Revision as of 10:00, 19 December 2005 editBobblewik (talk | contribs)66,026 editsm Assisted.Reduce links to date elements eg2005->2005. See Manual of Style. If you like this, please say so at Misplaced Pages talk:Bots#Bot_permission_please.3F← Previous edit | Latest revision as of 12:14, 15 January 2025 edit undoRafa9876 (talk | contribs)2 edits →Central and South America | ||
Line 1: | Line 1: | ||
{{Short description|Rise in sea levels due to climate change}} | |||
] records in geologically stable environments]] | |||
{{About|the current and projected rise in the world's average sea level|sea level rise in general|Past sea level}} | |||
] episode]] | |||
{{Redirect|Rising seas|the song|Rising Seas (song)}} | |||
{{Good article}} | |||
<noinclude>]</noinclude> | |||
'''Sea level rise''' is an increase in ]. Multiple complex factors may influence such changes. | |||
<noinclude> {{Webarchive|url=https://web.archive.org/web/20201125032604/https://svs.gsfc.nasa.gov/4853 |date=2020-11-25 }} ''NASA Visualization Studio'', 5 November 2020. {{PD-notice}}</ref>]]</noinclude> | |||
The sea level has risen more than 120 ]s since the peak of the last ] about 18,000 years ago. The bulk of that occurred before 6000 years ago. From 3000 years ago to the start of the 19th century sea level was almost constant, rising at 0.1 to 0.2 ]/yr; since 1900 the level has risen at 1 to 3 mm/yr {{ref|www.grida.no.275}}; since 1992 ] altimetry from ] indicates a rate of about 3 mm/yr {{ref|www.grida.no.276}}. This change may be the first signs of the ] of ] on sea level, which is predicted to cause significant rises in sea level over the course of the twenty-first century. | |||
Between 1901 and 2018, the average ] rose by {{cvt|15|–|25|cm|in|frac=2}}, with an increase of {{convert|2.3|mm|abbr=on}} per year since the 1970s.<ref name="IPCC AR6 WG1 Ch.9" />{{rp|1216}} This was faster than the sea level had ever risen over at least the past 3,000 years.<ref name="IPCC AR6 WG1 Ch.9" />{{rp|1216}} The rate accelerated to {{convert|4.62|mm|abbr=on}}/yr for the decade 2013–2022.<ref name=WMO_20230421/> ] due to human activities is the main cause.<ref name="IPCC_2021_WGI_SPM" />{{rp|5,8}} Between 1993 and 2018, melting ] and ]s accounted for 44% of sea level rise, with another 42% resulting from ] of ].<ref name="WCRP2018">{{cite journal |author=WCRP Global Sea Level Budget Group |year=2018 |title=Global sea-level budget 1993–present |journal=Earth System Science Data |volume=10 |issue=3 |pages=1551–1590 |bibcode=2018ESSD...10.1551W |doi=10.5194/essd-10-1551-2018 |quote=This corresponds to a mean sea-level rise of about 7.5 cm over the whole altimetry period. More importantly, the GMSL curve shows a net acceleration, estimated to be at 0.08mm/yr<sup>2</sup>. |doi-access=free|hdl=20.500.11850/287786 |hdl-access=free }}</ref>{{Rp|1576}} | |||
Over the last million years the sea level has changed by tens of meters many times, while many fewer variations of as much as 100 meters have taken place. Although during the past million years the sea level has generally been lower than it presently is, over geologic time scales the sea level has often been 100-200 meters higher than in recent times. | |||
Sea level rise lags behind changes in the ]'s temperature by many decades, and sea level rise will therefore continue to accelerate between now and 2050 in response to warming that has already happened.<ref name="us nrc 2011 long term slr">{{cite book |author=((National Academies of Sciences, Engineering, and Medicine)) |year=2011 |quote=Box SYN-1: Sustained warming could lead to severe impacts |chapter-url=https://nap.nationalacademies.org/read/12877/chapter/3 |page= |chapter=Synopsis |title=Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia |location=Washington, DC |publisher=The National Academies Press |doi=10.17226/12877 |isbn=978-0-309-15176-4 |access-date=2022-04-11 |archive-date=2023-06-30 |archive-url=https://web.archive.org/web/20230630084322/https://nap.nationalacademies.org/read/12877/chapter/3 |url-status=live }}</ref> What happens after that depends on human ]. If there are very deep cuts in emissions, sea level rise would slow between 2050 and 2100. It could then reach by 2100 slightly over {{cvt|30|cm|ft|frac=2}} from now and approximately {{cvt|60|cm|ft|frac=2}} from the 19th century. With high emissions it would instead accelerate further, and could rise by {{cvt|1.0|m|ft|frac=3}} or even {{cvt|1.6|m|ft|frac=3}} by 2100.<ref name="IPCC_2021_WGI_SPM" /><ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1302}} In the long run, sea level rise would amount to {{convert|2-3|m|ft|0|abbr=on}} over the next 2000 years if warming stays to its current {{convert|1.5|C-change|F-change}} over the pre-industrial past. It would be {{convert|19-22|m|ft}} if warming peaks at {{convert|5|C-change|F-change}}.<ref name="IPCC_2021_WGI_SPM">IPCC, 2021: {{Webarchive|url=https://web.archive.org/web/20210811205522/https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf |date=2021-08-11 }}. In: {{Webarchive|url=https://web.archive.org/web/20230526182346/https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf |date=2023-05-26 }} Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.). Cambridge University Press, Cambridge, UK and New York, US, pp. 3−32, {{doi|10.1017/9781009157896.001}}.</ref>{{rp|21}} | |||
==Overview== | |||
=== Local and eustatic sea level === | |||
], ], and ]s.]] | |||
Local “mean sea level” (LMSL) is defined as the height of the sea with respect to a land benchmark, averaged over a period of time, such as a month or a year, long enough that fluctuations caused by waves and tides are largely removed. One must adjust perceived changes in LMSL to take into account vertical movements of the land, which can be of the same order (mm/yr) as sea level changes. Some land movements occur due to the ] adjustment of the ] to the melting of ice sheets at the end of the last ]. Atmospheric pressure (the ]), ocean currents and local ocean temperature changes can all affect LMSL. | |||
Rising seas affect every coastal and island population on Earth.<ref name="wg1-5-5-1">{{cite book |author=Bindoff |first1=N. L. |title=Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change |last2=Willebrand |first2=J. |last3=Artale |first3=V. |last4=Cazenave |first4=A. |last5=Gregory |first5=J. |last6=Gulev |first6=S. |last7=Hanawa |first7=K. |last8=Le Quéré |first8=C. |last9=Levitus |first9=S. |date=2007 |isbn=978-0-521-88009-1 |editor=Solomon |editor-first=S. |language=en |chapter=Observations: Ocean Climate Change and Sea Level: §5.5.1: Introductory Remarks |author4-link=Anny Cazenave |access-date=25 January 2017 |editor2=Qin |editor-first2=D. |editor3=Manning |editor-first3=M. |editor4=Chen |editor-first4=Z. |editor5=Marquis |editor-first5=M. |editor6=Averyt |editor-first6=K. B. |editor7=Tignor |editor-first7=M. |editor8=Miller |editor-first8=H. L. |chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-5.html#5-5-1 |archive-url=https://web.archive.org/web/20170620210108/http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5.html |archive-date=20 June 2017 |author10=Nojiri, Y. |author11=Shum, C. K. |author12=Talley, L. D. |author13=Unnikrishnan, A.|publisher=Cambridge University Press}}</ref> This can be through flooding, higher ]s, ]s, and ]s. There are many knock-on effects. They lead to loss of coastal ]s like ]. ]s may reduce because of ] in ] water. Damage to ports disrupts sea trade.<ref name="IPCC-2001" /><ref name="Holder-2017" /> The sea level rise projected by 2050 will expose places currently inhabited by tens of millions of people to annual flooding. Without a sharp reduction in greenhouse gas emissions, this may increase to hundreds of millions in the latter decades of the century.<ref name="Kulp2019" /> | |||
“]” change (as opposed to local change) results in an alteration to the global sea levels, such as changes in the volume of water in the world oceans or changes in the volume of an ocean basin. | |||
Local factors like ] or land ] will greatly affect the severity of impacts. For instance, ] is likely to be two to three times greater than the global average by the end of the century.<ref>{{cite web |last1=Choi |first1=Charles Q. |date=27 June 2012|title=Sea Levels Rising Fast on U.S. East Coast |url=https://www.nationalgeographic.com/science/article/120625-sea-level-rise-east-coast-us-science-nature-climate-change |archive-url=https://web.archive.org/web/20210504002931/https://www.nationalgeographic.com/science/article/120625-sea-level-rise-east-coast-us-science-nature-climate-change |archive-date=May 4, 2021 |access-date=October 22, 2022 |website=National Oceanic and Atmospheric Administration}}</ref><ref name="NOAA-2022">{{Cite web |title=2022 Sea Level Rise Technical Report |url=https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html |access-date=2022-07-04 |website=oceanservice.noaa.gov |language=EN-US |archive-date=2022-11-29 |archive-url=https://web.archive.org/web/20221129070303/https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html |url-status=live }}</ref> Yet, of the 20 countries with the greatest exposure to sea level rise, twelve are in ], including ], ] and the Philippines.<ref name="AR6_WGII_Chapter10" /> The resilience and ] of ecosystems and countries also varies, which will result in more or less pronounced impacts.<ref>{{Cite journal|last=Mimura|first=Nobuo|date=2013|title=Sea-level rise caused by climate change and its implications for society|journal=Proceedings of the Japan Academy. Series B, Physical and Biological Sciences|volume=89|issue=7|pages=281–301|doi=10.2183/pjab.89.281|issn=0386-2208|pmc=3758961|pmid=23883609|bibcode=2013PJAB...89..281M}}</ref> The greatest ] in the near term will occur in the low-lying ] and ]. Sea level rise will make many of them uninhabitable later this century.<ref name="AR6_WGII_Chapter15">Mycoo, M., M. Wairiu, D. Campbell, V. Duvat, Y. Golbuu, S. Maharaj, J. Nalau, P. Nunn, J. Pinnegar, and O. Warrick, 2022: {{Webarchive|url=https://web.archive.org/web/20230630084058/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter15.pdf |date=2023-06-30 }}. In {{Webarchive|url=https://web.archive.org/web/20220228114918/https://www.ipcc.ch/report/ar6/wg2/ |date=2022-02-28 }} . Cambridge University Press, Cambridge, UK and New York, US, pp. 2043–2121. | |||
=== Short term and periodic changes === | |||
{{doi|10.1017/9781009325844.017}}.</ref> | |||
There are a variety of factors which can produce short-term (a few minutes to 14 months) changes in sea level. | |||
Societies can adapt to sea level rise in multiple ways. ], ], or protecting against sea level rise through hard-construction practices like ]s<ref>{{cite web |year=2013 |title=IPCC's New Estimates for Increased Sea-Level Rise |url=http://www.yaleclimateconnections.org/2013/10/ipccs-new-estimates-for-increased-sea-level-rise/ |publisher=Yale University Press |access-date=2015-09-01 |archive-date=2020-03-28 |archive-url=https://web.archive.org/web/20200328215506/https://www.yaleclimateconnections.org/2013/10/ipccs-new-estimates-for-increased-sea-level-rise/ |url-status=live }}</ref> are hard approaches. There are also soft approaches such as ] and ]. Sometimes these adaptation strategies go hand in hand. At other times choices must be made among different strategies.<ref name="Thomsen-2012">{{Cite journal |last1=Thomsen |first1=Dana C. |last2=Smith |first2=Timothy F. |last3=Keys |first3=Noni |date=2012 |title=Adaptation or Manipulation? Unpacking Climate Change Response Strategies |journal=Ecology and Society |volume=17 |issue=3 |doi=10.5751/es-04953-170320 |jstor=26269087 |doi-access=free|hdl=10535/8585 |hdl-access=free }}</ref> Poorer nations may also struggle to implement the same approaches to adapt to sea level rise as richer states. | |||
{| class="wikitable" | |||
{{TOC level|3}} | |||
! Short-term (periodic) causes | |||
! Time scale <br> (P = period) | |||
! Vertical effect | |||
|- | |||
! colspan="3" style="background:lightgray" | Periodic sea level changes | |||
|- | |||
| Astronomical ]s || 6-12 h P || 0.2-10+ m | |||
|- | |||
| Long-period tides || || | |||
|- | |||
| Rotational variations (]) || 14 month P | |||
|- | |||
! colspan="3" style="background:lightgray" | Meteorological and oceanographic fluctuations | |||
|- | |||
| ] || || | |||
|- | |||
| Winds (]s) || 1-5 days || Up to 5 m | |||
|- | |||
| Evaporation and precipitation (may also follow long-term pattern) || Days to weeks || | |||
|- | |||
| Ocean surface topography (changes in water density and currents) || Days to weeks || Up to 1 m | |||
|- | |||
| ]/southern oscillation || 6 mo every 5-10 yr || Up to 0.6 m | |||
|- | |||
! colspan="3" style="background:lightgray" | Seasonal variations | |||
|- | |||
| Seasonal water balance among oceans (Atlantic, Pacific, Indian) || || | |||
|- | |||
| Seasonal variations in slope of water surface || || | |||
|- | |||
| River runoff/floods || 2 months || 1 m | |||
|- | |||
| Seasonal water density changes (temperature and salinity) || 6 months || 0.2 m | |||
|- | |||
! colspan="3" style="background:lightgray" | Seiches | |||
|- | |||
| ]s (standing waves) || Minutes-hours || Up to 2 m | |||
|- | |||
! colspan="3" style="background:lightgray" | Earthquakes | |||
|- | |||
| ]s (generate catastrophic long-period waves) || Hours || Up to 10 m | |||
|- | |||
| Abrupt change in land level || Minutes || Up to 10 m | |||
|} | |||
== Observations == | |||
=== Longer term changes === | |||
]Between 1901 and 2018, the global mean sea level rose by about {{convert|20|cm|abbr=on}}.<ref name="IPCC_2021_WGI_SPM" /> More precise data gathered from satellite ] measurements found an increase of {{convert|7.5|cm|abbr=on}} from 1993 to 2017 (average of {{convert|2.9|mm|abbr=on}}/yr).<ref name="WCRP2018" /> This accelerated to {{convert|4.62|mm|abbr=on}}/yr for 2013–2022.<ref name="WMO_20230421">{{cite web |date=21 April 2023 |title=WMO annual report highlights continuous advance of climate change |url=https://wmo.int/news/media-centre/wmo-annual-report-highlights-continuous-advance-of-climate-change |publisher=World Meteorological Organization |quote=Press Release Number: 21042023. |access-date=18 December 2023 |archive-date=17 December 2023 |archive-url=https://web.archive.org/web/20231217002918/https://wmo.int/news/media-centre/wmo-annual-report-highlights-continuous-advance-of-climate-change |url-status=live }}</ref> ] data shows that this rate of sea level rise is the fastest it had been over at least the past 3,000 years.<ref name="IPCC AR6 WG1 Ch.9" />{{rp|1216}} | |||
] | |||
Various factors affect the volume or mass of the ocean, leading to long-term changes in eustatic sea level. The two primary influences are ] (because the volume of ] depends on temperature), and the ] of water locked up on land and sea as fresh water in rivers, lakes, glaciers, polar ice caps, and sea ice. Over much longer (]) timescales, changes in the shape of the ocean basins and in land/sea distribution will affect sea level. | |||
While sea level rise is uniform around the globe, some land masses are moving up or down as a consequence of ] (land sinking or settling) or ] (land rising as melting ice reduces weight). Therefore, local ] rise may be higher or lower than the global average. Changing ice masses also affect the distribution of sea water around the globe through gravity.<ref>{{Cite journal |last1=Katsman |first1=Caroline A. |last2=Sterl |first2=A. |last3=Beersma |first3=J. J. |last4=van den Brink |first4=H. W. |last5=Church |first5=J. A. |last6=Hazeleger |first6=W. |last7=Kopp |first7=R. E. |last8=Kroon |first8=D. |last9=Kwadijk |first9=J. |date=2011 |title=Exploring high-end scenarios for local sea level rise to develop flood protection strategies for a low-lying delta—the Netherlands as an example |journal=Climatic Change |volume=109 |issue=3–4 |pages=617–645 |doi=10.1007/s10584-011-0037-5 |issn=0165-0009 |s2cid=2242594 |doi-access=free|bibcode=2011ClCh..109..617K }}</ref><ref name="ipcc13">{{cite book |last1=Church |first1=J. A. |title=Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change |last2=Clark |first2=P. U. |publisher=Cambridge University Press |year=2013 |editor-last=Stocker |editor-first=T. F. |location=Cambridge, UK and New York, US |chapter=Sea Level Change |access-date=2018-08-12 |display-editors=etal |chapter-url=https://ipcc.ch/report/ar5/wg1/ |archive-url=https://web.archive.org/web/20200509055710/https://www.ipcc.ch/report/ar5/wg1/ |archive-date=2020-05-09 |url-status=live}}</ref> | |||
Observational estimates are that the rise in sea level due to rising temperature is about 1 mm/yr over recent decades. Observational and modelling studies of glaciers and ice caps indicate a contribution to sea-level rise of 0.2 to 0.4 mm/yr averaged over the 20th century. | |||
== Projections == | |||
====Glaciers and ice caps==== | |||
===Approaches used for projections=== | |||
Each year about 8 mm (0.3 inches) of water from the entire surface of the oceans goes into the Antarctica and Greenland ice sheets as snowfall. If no ice returned to the oceans, sea level would drop 80 mm (3 inches) every 10 years. Although approximately the same amount of water returns to the ocean in icebergs and from ice melting at the edges, scientists do not know which is greater -- the ice going in or the ice coming out. The difference between the ice input and output is called the '''mass balance''' and is important because it causes changes in global sea level. | |||
] | |||
Several approaches are used for sea level rise (SLR) projections.<ref name="Slangen2022" /> One is process-based modeling, where ice melting is computed through an ] and rising sea temperature and expansion through a ], and then these contributions are added up.<ref name="Moore2013">{{cite journal |last1=Moore |first1=John C. |last2=Grinsted |first2=Aslak |last3=Zwinger |first3=Thomas |last4=Jevrejeva |first4=Svetlana |date=10 June 2013 |title=Semiempirical and process-based global sea level projections |journal=Reviews of Geophysics |volume=51 |issue=3 |pages=484–522 |doi=10.1002/rog.20015 |bibcode=2013RvGeo..51..484M}}</ref> The so-called semi-empirical approach instead applies statistical techniques and basic physical modeling to the observed sea level rise and its reconstructions from the historical geological data (known as ] modeling).<ref name="Mengel2016" /> It was developed because process-based model projections in the past IPCC reports (such as the ] from 2007) were found to underestimate the already observed sea level rise.<ref name="Moore2013" /> | |||
] float on the surface of the sea and, if they melt, to first order they do not change sea level. Because they are fresh, however, their melting would cause a very small increase in sea levels, so small that it is generally neglected. It can however be argued that if ice shelves melt it is a precursor to the melting of ice sheets on Greenland and Antarctica. | |||
By 2013, improvements in modeling had addressed this issue, and model and semi-empirical projections for the year 2100 are now very similar.<ref name="Moore2013" /><ref name="Slangen2022" /> Yet, semi-empirical estimates are reliant on the quality of available observations and struggle to represent non-linearities, while processes without enough available information about them cannot be modeled.<ref name="Moore2013" /> Thus, another approach is to combine the opinions of a large number of scientists in what is known as a structured expert judgement (SEJ).<ref name="Slangen2022" /> | |||
* Scientists lack knowledge of changes in terrestrial storage of water. Between 1910 and 1990 such changes may have contributed from –1.1 to +0.4 mm/yr. | |||
* If all ] and ] melt, the projected rise in sea-level will be around 0.5 m. If the melting includes the ] and ] ] (both of which contain ice above sea level), then the rise is a more drastic 68.8 m. {{ref|www.grida.no.277}} | |||
* Climate changes during the 20th century are estimated from modelling studies to have led to contributions of between –0.2 and 0.0 mm/yr from Antarctica (the results of increasing precipitation) and 0.0 to 0.1 mm/yr from Greenland (from changes in both precipitation and runoff). | |||
* Estimates suggest that Greenland and Antarctica have contributed 0.0 to 0.5 mm/yr over the 20th century as a result of long-term adjustment to the end of the last ice age. | |||
Variations of these primary approaches exist.<ref name="Slangen2022" /> For instance, large climate models are always in demand, so less complex models are often used in their place for simpler tasks like projecting flood risk in the specific regions. A structured expert judgement may be used in combination with modeling to determine which outcomes are more or less likely, which is known as "shifted SEJ". Semi-empirical techniques can be combined with the so-called "intermediate-complexity" models.<ref name="Slangen2022" /> After 2016, some ice sheet modeling exhibited the so-called ice cliff instability in Antarctica, which results in substantially faster disintegration and retreat than otherwise simulated.<ref name="DeConto2016">{{Cite journal |last1=DeConto |first1=Robert M. |last2=Pollard |first2=David |date=30 March 2016 |title=Contribution of Antarctica to past and future sea-level rise |journal=Nature |language=en |volume=531 |issue=7596 |pages=591–597 |doi=10.1038/nature17145 |pmid=27029274 |bibcode=2016Natur.531..591D |s2cid=205247890}}</ref><ref>{{cite news |last=Gillis |first=Justin |date=30 March 2016 |title=Climate Model Predicts West Antarctic Ice Sheet Could Melt Rapidly |newspaper=The New York Times |url=https://www.nytimes.com/2016/03/31/science/global-warming-antarctica-ice-sheet-sea-level-rise.html |access-date=28 May 2024 |archive-date=9 June 2024 |archive-url=https://web.archive.org/web/20240609214842/https://www.nytimes.com/2016/03/31/science/global-warming-antarctica-ice-sheet-sea-level-rise.html |url-status=live }}</ref> The differences are limited with low warming, but at higher warming levels, ice cliff instability predicts far greater sea level rise than any other approach.<ref name="Slangen2022">{{cite journal |last1=Slangen |first1=A. B. A. |last2=Haasnoot |first2=M. |last3=Winter |first3=G. |date=30 March 2022 |title=Rethinking Sea-Level Projections Using Families and Timing Differences |journal=Earth's Future |volume=10 |issue=4 |page=e2021EF002576 |doi=10.1029/2021EF002576 |bibcode=2022EaFut..1002576S |url=https://www.vliz.be/imisdocs/publications/00/378000.pdf |access-date=28 May 2024 |archive-date=26 May 2024 |archive-url=https://web.archive.org/web/20240526230811/https://www.vliz.be/imisdocs/publications/00/378000.pdf |url-status=live }}</ref> | |||
The current rise in sea level observed from tide gauges, of about 1.8 mm/yr, is within the estimate range from the combination of factors above {{ref|www.grida.no.278}} but active research continues in this field. The uncertainty in the terrestrial storage term is particularly large. | |||
=== Projections for the 21st century === | |||
Since 1992 the TOPEX and JASON satellite programs have provided measurements of sea level change. The current data are available at {{ref|refbot.279}}. The data show a mean sea level increase of 2.8±0.4 mm/yr. This includes an apparent increase to 3.7±0.2 mm/yr during the period 1999 through 2004 {{ref|membrane.com.280}}. However, because significant short-term variability in sea level can occur, this recent increase does not necessarily indicate a long-term acceleration in sea level changes. Also, it should be noted that since satellite results are partially calibrated against tide gauge readings, they are not an entirely independent source. {{ref|sealevel.colorado.edu.281}} | |||
].<ref name="NOAA-2017">{{Cite web|url=https://tidesandcurrents.noaa.gov/publications/techrpt83_Global_and_Regional_SLR_Scenarios_for_the_US_final.pdf|title=January 2017 analysis from NOAA: Global and Regional Sea Level Rise Scenarios for the United States|access-date=2017-02-06|archive-date=2017-12-18|archive-url=https://web.archive.org/web/20171218140625/https://tidesandcurrents.noaa.gov/publications/techrpt83_Global_and_Regional_SLR_Scenarios_for_the_US_final.pdf|url-status=live}}</ref> RCPs are different scenarios for future concentrations of greenhouse gases.]] | |||
The ] is the largest and most influential scientific organization on climate change, and since 1990, it provides several plausible scenarios of 21st century sea level rise in each of its major reports. The differences between scenarios are mainly due to uncertainty about future ] emissions. These depend on future economic developments, and also future political action which is hard to predict. Each scenario provides an estimate for sea level rise as a range with a lower and upper limit to reflect the unknowns. The scenarios in the 2013–2014 ] (AR5) were called ]s, or RCPs and the scenarios in the ] (AR6) are known as ], or SSPs. A large difference between the two was the addition of SSP1-1.9 to AR6, which represents meeting the best ] goal of {{convert|1.5|C-change|F-change}}. In that case, the likely range of sea level rise by 2100 is {{cvt|28–55|cm|in|frac=2}}.<ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1302}} | |||
==== Geological influences ==== | |||
] projections from 2020 (lower left), research modeling the possibility of ice cliff instability (upper right) and combined expert projections of sea level rise from Greenland and Antarctica (lower right) were all considered before settling on the projections. Note that projections on the right use a larger scale, which ends at {{cvt|2.5|m|ft|frac=3}} instead of {{cvt|1.5|m|ft|frac=3}}<ref name="Kopp2023" /> ]] | |||
] | |||
The lowest scenario in AR5, RCP2.6, would see greenhouse gas emissions low enough to meet the goal of limiting warming by 2100 to {{convert|2|C-change|F-change}}. It shows sea level rise in 2100 of about {{convert|44|cm|abbr=on}} with a range of {{convert|28|-|61|cm|abbr=on}}. The "moderate" scenario, where {{CO2}} ''emissions'' take a decade or two to peak and its atmospheric ''concentration'' does not plateau until the 2070s is called RCP 4.5. Its likely range of sea level rise is {{cvt|36–71|cm|in|frac=2}}. The highest scenario in RCP8.5 pathway sea level would rise between {{cvt|52 and 98|cm|in|frac=2}}.<ref name="ipcc13" /><ref name="CAT" >{{cite web |url=https://climateactiontracker.org/global/cat-thermometer/ |title=The CAT Thermometer |access-date=8 January 2023 |archive-date=14 April 2019 |archive-url=https://web.archive.org/web/20190414131223/https://climateactiontracker.org/global/cat-thermometer/ |url-status=live }}</ref> AR6 had equivalents for both scenarios, but it estimated larger sea level rise under both. In AR6, the SSP1-2.6 pathway results in a range of {{cvt|32–62|cm|in|frac=2}} by 2100. The "moderate" SSP2-4.5 results in a {{cvt|44–76|cm|in|frac=2}} range by 2100 and SSP5-8.5 led to {{cvt|65–101|cm|in|frac=2}}.<ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1302}} | |||
This general increase of projections in AR6 came after the improvements in ice-sheet modeling and the incorporation of structured expert judgements.<ref name="Kopp2023" /> These decisions came as the observed ice-sheet erosion ] and ] had matched the upper-end range of the AR5 projections by 2020,<ref>{{cite news |title=Ice sheet melt on track with 'worst-case climate scenario' |language=en |work=www.esa.int |url=https://www.esa.int/Applications/Observing_the_Earth/Space_for_our_climate/Ice_sheet_melt_on_track_with_worst-case_climate_scenario |access-date=8 September 2020 |archive-date=9 June 2023 |archive-url=https://web.archive.org/web/20230609213115/https://www.esa.int/Applications/Observing_the_Earth/Space_for_our_climate/Ice_sheet_melt_on_track_with_worst-case_climate_scenario |url-status=live }}</ref><ref name="Slater-2020">{{cite journal |last1=Slater |first1=Thomas |last2=Hogg |first2=Anna E. |last3=Mottram |first3=Ruth |author-link3=Ruth Mottram |date=31 August 2020 |title=Ice-sheet losses track high-end sea-level rise projections |url=https://www.nature.com/articles/s41558-020-0893-y |journal=Nature Climate Change |language=en |volume=10 |issue=10 |pages=879–881 |bibcode=2020NatCC..10..879S |doi=10.1038/s41558-020-0893-y |issn=1758-6798 |archive-url=https://web.archive.org/web/20200902132539/https://www.nature.com/articles/s41558-020-0893-y |archive-date=2 September 2020 |access-date=8 September 2020 |s2cid=221381924}}</ref> and the finding that AR5 projections were likely too slow next to an extrapolation of observed sea level rise trends, while the subsequent reports had improved in this regard.<ref name="Grinsted-2021">{{Cite journal |last1=Grinsted |first1=Aslak |last2=Christensen |first2=Jens Hesselbjerg |date=2 February 2021 |title=The transient sensitivity of sea level rise |url=https://os.copernicus.org/articles/17/181/2021/ |journal=Ocean Science |volume=17 |issue=1 |pages=181–186 |bibcode=2021OcSci..17..181G |doi=10.5194/os-17-181-2021 |issn=1812-0784 |s2cid=234353584 |doi-access=free |hdl=11250/3135359 |hdl-access=free |access-date=3 February 2021 |archive-date=19 June 2022 |archive-url=https://web.archive.org/web/20220619123914/https://os.copernicus.org/articles/17/181/2021/ |url-status=live }}</ref> Further, AR5 was criticized by multiple researchers for excluding detailed estimates the impact of "low-confidence" processes like marine ice sheet and marine ice cliff instability,<ref name="pmid30013142" /><ref name="Pollard2015" /><ref name="Hansen2016">{{cite journal |last1=Hansen |first1=James |last2=Sato |first2=Makiko |last3=Hearty |first3=Paul |last4=Ruedy |first4=Reto |last5=Kelley |first5=Maxwell |last6=Masson-Delmotte |first6=Valerie |last7=Russell |first7=Gary |last8=Tselioudis |first8=George |last9=Cao |first9=Junji |last10=Rignot |first10=Eric |last11=Velicogna |first11=Isabella |date=22 March 2016 |title=Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous |journal=Atmospheric Chemistry and Physics |volume=16 |issue=6 |pages=3761–3812 |arxiv=1602.01393 |bibcode=2016ACP....16.3761H |doi=10.5194/acp-16-3761-2016 |first18=Michael |first19=Kwok-Wai |last19=Lo |first12=Blair |last18=Bauer |first17=Allegra N. |last17=Legrande |first16=Pushker |last16=Kharecha |first15=Karina |last15=von Schuckmann |first14=Evgeniya |last14=Kandiano |first13=Bailey |last13=Donovan |last12=Tormey |author-link11=Isabella Velicogna |s2cid=9410444 |doi-access=free}}</ref> which can substantially accelerate ice loss to potentially add "tens of centimeters" to sea level rise within this century.<ref name="ipcc13" /> AR6 includes a version of SSP5-8.5 where these processes take place, and in that case, sea level rise of up to {{cvt|1.6|m|ft|frac=3}} by 2100 could not be ruled out.<ref name="IPCC AR6 WG1 Ch.9">{{Cite journal |last1=Fox-Kemper |first1=B. |last2=Hewitt |first2=Helene T. |author2-link=Helene Hewitt |last3=Xiao |first3=C. |last4=Aðalgeirsdóttir |first4=G. |last5=Drijfhout |first5=S. S. |last6=Edwards |first6=T. L. |last7=Golledge |first7=N. R. |last8=Hemer |first8=M. |last9=Kopp |first9=R. E. |last10=Krinner |first10=G. |last11=Mix |first11=A. |date=2021 |editor-last=Masson-Delmotte |editor-first=V. |editor2-last=Zhai |editor2-first=P. |editor3-last=Pirani |editor3-first=A. |editor4-last=Connors |editor4-first=S. L. |editor5-last=Péan |editor5-first=C. |editor6-last=Berger |editor6-first=S. |editor7-last=Caud |editor7-first=N. |editor8-last=Chen |editor8-first=Y. |editor9-last=Goldfarb |editor9-first=L. |title=Chapter 9: Ocean, Cryosphere and Sea Level Change |url=https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf |journal=Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change |publisher=Cambridge University Press, Cambridge, UK and New York, US |page= |access-date=2022-10-18 |archive-date=2022-10-24 |archive-url=https://web.archive.org/web/20221024162651/https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf |url-status=live }}</ref>{{Rp|page=1302}} | |||
At times during Earth's long history, continental drift has arranged the land masses into very different configurations from those of today. When there were large amounts of continental crust near the poles, the rock record shows unusually low sea levels during ice ages, because there was lots of polar land mass upon which snow and ice could accumulate. During times when the land masses clustered around the equator, ice ages had much less effect on sea level. However, over most of geologic time, long-term sea level has been higher than today (see graph above). Only during at the Permo-Triassic boundary ~250 million years ago was long-term sea level lower than today. | |||
==== Role of instability processes ==== | |||
During the glacial/interglacial cycles over the past few million years, sea level has varied by somewhat more than a hundred metres. This is primarily due to the growth and decay of ice sheets (mostly in the northern hemisphere) with water evaporated from the sea. The melting of the Greenland and Antarctica ice sheets would result in a sea level rise of approximately 80 meters. | |||
] | |||
The greatest uncertainty with sea level rise projections is associated with the so-called ] (MISI), and, even more so, ''Marine Ice Cliff Instability'' (MICI).<ref name="Robel2019" /><ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1302}} These processes are mainly associated with West Antarctic Ice Sheet, but may also apply to some of Greenland's glaciers.<ref name="Zhang2022" /> The former suggests that when glaciers are mostly underwater on retrograde (backwards-sloping) bedrock, the water melts more and more of their height as their retreat continues, thus accelerating their breakdown on its own. This is widely accepted, but is difficult to model.<ref name="Robel2019" /><ref name="Zhang2022" /> | |||
The latter posits that coastal ice cliffs which exceed ~{{cvt|90|m|ft|frac=2}} in above-ground height and are ~{{cvt|800|m|ft|frac=2}} in basal (underground) height are likely to rapidly collapse under their own weight once the ] propping them up are gone.<ref name="Zhang2022" /> The collapse then exposes the ice masses following them to the same instability, potentially resulting in a self-sustaining cycle of cliff collapse and rapid ice sheet retreat.<ref name="Pollard2015" /><ref name="Pattyn 2018">{{Cite journal |last=Pattyn |first=Frank |author-link=Frank Pattyn |date=2018 |title=The paradigm shift in Antarctic ice sheet modelling |journal=Nature Communications |language=En |volume=9 |issue=1 |page=2728 |bibcode=2018NatCo...9.2728P |doi=10.1038/s41467-018-05003-z |issn=2041-1723 |pmc=6048022 |pmid=30013142}}</ref><ref>{{Cite journal|last1=Dow|first1=Christine F.|last2=Lee|first2=Won Sang|last3=Greenbaum|first3=Jamin S.|last4=Greene|first4=Chad A.|last5=Blankenship|first5=Donald D.|last6=Poinar|first6=Kristin|last7=Forrest|first7=Alexander L.|last8=Young|first8=Duncan A.|last9=Zappa|first9=Christopher J.|date=2018-06-01|title=Basal channels drive active surface hydrology and transverse ice shelf fracture|journal=Science Advances|language=en|volume=4|issue=6|pages=eaao7212|doi=10.1126/sciadv.aao7212|issn=2375-2548|pmc=6007161|pmid=29928691|bibcode=2018SciA....4.7212D}}</ref> This theory had been highly influential - in a 2020 survey of 106 experts, the 2016 paper which suggested {{cvt|1|m|ft|frac=2}} or more of sea level rise by 2100 from Antarctica alone,<ref name="DeConto2016"/> was considered even more important than the 2014 ].<ref name="Horton2020">{{Cite journal |last1=Horton |first1=Benjamin P. |last2=Khan |first2=Nicole S. |last3=Cahill |first3=Niamh |last4=Lee |first4=Janice S. H. |last5=Shaw |first5=Timothy A. |last6=Garner |first6=Andra J. |last7=Kemp |first7=Andrew C. |last8=Engelhart |first8=Simon E. |last9=Rahmstorf |first9=Stefan |date=2020-05-08 |title=Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey |journal=npj Climate and Atmospheric Science |volume=3 |issue=1 |page=18 |doi=10.1038/s41612-020-0121-5 |bibcode=2020npCAS...3...18H |s2cid=218541055 |hdl=10356/143900 |hdl-access=free}}</ref> Even more rapid sea level rise was proposed in a 2016 study led by ], which hypothesized multi-meter sea level rise in 50–100 years as a plausible outcome of high emissions,<ref name="Hansen2016" /> but it remains a minority view amongst the scientific community.<ref>{{cite news |year=2015 |title=James Hansen's controversial sea level rise paper has now been published online |newspaper=The Washington Post |url=https://www.washingtonpost.com/news/energy-environment/wp/2015/07/23/controversial-sea-level-rise-paper-is-now-published-online/ |quote="There is no doubt that the sea level rise, within the IPCC, is a very conservative number," says ], a climate and hurricane researcher at the ], who has also reviewed the Hansen study. "So the truth lies somewhere between IPCC and Jim." |access-date=2017-09-11 |archive-date=2019-11-26 |archive-url=https://web.archive.org/web/20191126005216/https://www.washingtonpost.com/news/energy-environment/wp/2015/07/23/controversial-sea-level-rise-paper-is-now-published-online/ |url-status=live }}</ref> | |||
<br style="clear:both;"> | |||
] (viewed from the top) would do a lot to determine how quickly it may proceed<ref name="Schlemm2022" />]] | |||
{| class="wikitable" | |||
Marine ice cliff instability had also been very controversial, since it was proposed as a modelling exercise,<ref name="Zhang2022">{{Cite conference |last=Zhang |first=Zhe |date=7 November 2021 |title=Reviewing the elements of marine ice cliff instability |conference=The International Conference on Materials Chemistry and Environmental Engineering (CONF-MCEE 2021) |location=California, United States |journal=Journal of Physics: Conference Series |volume=2152 |doi=10.1088/1742-6596/2152/1/012057 |doi-access=free }}</ref> and the observational evidence from both the past and the present is very limited and ambiguous.<ref name="Gilford2020" /> So far, only one episode of ] from the ] period appears truly consistent with this theory,<ref name="Wise2017" /> but it had lasted for an estimated 900 years,<ref name="Wise2017">{{Cite journal |last1=Wise |first1=Matthew G. |last2=Dowdeswell |first2=Julian A. |last3=Jakobsson |first3=Martin |last4=Larter |first4=Robert D. |date=October 2017 |title=Evidence of marine ice-cliff instability in Pine Island Bay from iceberg-keel plough marks |url=https://nora.nerc.ac.uk/id/eprint/514800/1/Nature_final_accepted_ms.pdf |journal=Nature |language=en |volume=550 |issue=7677 |pages=506–510 |doi=10.1038/nature24458 |pmid=29072274 |bibcode=2017Natur.550..506W |issn=0028-0836 |archive-url=https://web.archive.org/web/20200506155034/https://nora.nerc.ac.uk/id/eprint/514800/1/Nature_final_accepted_ms.pdf |archive-date=May 6, 2020}}</ref> so it is unclear if it supports rapid sea level rise in the present.<ref name="Gilford2020" /> Modelling which investigated the hypothesis after 2016 often suggested that the ice shelves in the real world may collapse too slowly to make this scenario relevant,<ref>{{cite journal |last1=Clerc |first1=Fiona |last2=Minchew |first2=Brent M. |last3=Behn |first3=Mark D. |date=21 October 2019 |title=Marine Ice Cliff Instability Mitigated by Slow Removal of Ice Shelves |url=https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2019GL084183 |journal=Geophysical Research Letters |volume=50 |issue=4 |pages=e2022GL102400 |doi=10.1029/2019GL084183 |bibcode=2019GeoRL..4612108C |via=American Geophysical Union |hdl=1912/25343 |hdl-access=free |access-date=3 June 2024 |archive-date=3 June 2024 |archive-url=https://web.archive.org/web/20240603163939/https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2019GL084183 |url-status=live }}</ref> or that ] - debris produced as the glacier breaks down - would quickly build up in front of the glacier and significantly slow or even outright stop the instability soon after it began.<ref>{{cite news|url=https://www.sciencenews.org/article/climate-marine-ice-cliffs-sheets-collapse-not-inevitable-sea-level|title=Collapse may not always be inevitable for marine ice cliffs|last1=Perkins|first1=Sid|date=17 June 2021|access-date=9 January 2023|agency=ScienceNews|archive-date=23 March 2023|archive-url=https://web.archive.org/web/20230323154132/https://www.sciencenews.org/article/climate-marine-ice-cliffs-sheets-collapse-not-inevitable-sea-level|url-status=live}}</ref><ref>{{Cite journal |last1=Bassis |first1=J. N. |last2=Berg |first2=B. |last3=Crawford |first3=A. J. |last4=Benn |first4=D. I. |date=18 June 2021 |title=Transition to marine ice cliff instability controlled by ice thickness gradients and velocity |url=https://www.science.org/doi/10.1126/science.abf6271 |journal=Science |language=en |volume=372 |issue=6548 |pages=1342–1344 |bibcode=2021Sci...372.1342B |doi=10.1126/science.abf6271 |issn=0036-8075 |pmid=34140387 |hdl-access=free |hdl=10023/23422 |access-date=3 June 2024 |archive-date=3 June 2024 |archive-url=https://web.archive.org/web/20240603163939/https://www.science.org/doi/10.1126/science.abf6271 |url-status=live }}</ref><ref>{{Cite journal |last1=Crawford |first1=Anna J. |last2=Benn |first2=Douglas I. |last3=Todd |first3=Joe |last4=Åström |first4=Jan A. |last5=Bassis |first5=Jeremy N. |last6=Zwinger |first6=Thomas |date=11 May 2021 |title=Marine ice-cliff instability modeling shows mixed-mode ice-cliff failure and yields calving rate parameterization |journal=Nature Communications |volume=12 |issue=1 |page=2701 |doi=10.1038/s41467-021-23070-7 |pmid=33976208 |pmc=8113328 |bibcode=2021NatCo..12.2701C }}</ref><ref name="Schlemm2022">{{Cite journal |last1=Schlemm |first1=Tanja |last2=Feldmann |first2=Johannes |last3=Winkelmann |first3=Ricarda |last4=Levermann |first4=Anders |date=24 May 2022 |title=Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet |journal=The Cryosphere |volume=16 |issue=5 |pages=1979–1996 |doi=10.5194/tc-16-1979-2022 |doi-access=free|bibcode=2022TCry...16.1979S }}</ref> | |||
! Long-term causes | |||
! Range of effect | |||
! Vertical effect | |||
|- | |||
! colspan="3" style="background:lightgray" | Change in volume of ocean basins | |||
|- | |||
| ] and seafloor spreading (plate divergence/convergence) and change in seafloor elevation (mid-ocean volcanism) || Eustatic || 0.01 mm/yr | |||
|- | |||
| Marine ]ation || Eustatic || < 0.01 mm/yr | |||
|- | |||
! colspan="3" style="background:lightgray" | Change in mass of ocean water | |||
|- | |||
| Melting or accumulation of continental ice || Eustatic || 10 mm/yr | |||
|- | |||
| colspan="3" | • '''Climate changes during the 20th century''' | |||
|- | |||
| •• ] (the results of increasing precipitation) || Eustatic || -0.2 to 0.0 mm/yr | |||
|- | |||
| •• ] (from changes in both precipitation and runoff) || Eustatic || 0.0 to 0.1 mm/yr | |||
|- | |||
| colspan="3" | • '''Long-term adjustment to the end of the last ice age''' | |||
|- | |||
| •• Greenland and Antarctica contribution over 20th century || Eustatic || 0.0 to 0.5 mm/yr | |||
|- | |||
| Release of water from earth's interior || Eustatic | |||
|- | |||
| Release or accumulation of continental hydrologic reservoirs || Eustatic | |||
|- | |||
! colspan="3" style="background:lightgray" | Uplift or subsidence of Earth's surface (]) | |||
|- | |||
| Thermal-isostasy (temperature/density changes in earth's interior) || Local effect | |||
|- | |||
| Glacio-isostasy (loading or unloading of ice) || Local effect|| 10 mm/yr | |||
|- | |||
| Hydro-isostasy (loading or unloading of water) || Local effect | |||
|- | |||
| Volcano-isostasy (magmatic extrusions) || Local effect | |||
|- | |||
| Sediment-isostasy (deposition and erosion of sediments) || Local effect|| < 4 mm/yr | |||
|- | |||
! colspan="3" style="background:lightgray" | Tectonic uplift/subsidence | |||
|- | |||
| Vertical and horizontal motions of crust (in response to fault motions) || Local effect|| 1-3 mm/yr | |||
|- | |||
! colspan="3" style="background:lightgray" | Sediment compaction | |||
|- | |||
| Sediment compression into denser matrix (particularly significant in and near ]s) || Local effect | |||
|- | |||
| Loss of interstitial fluids (withdrawal of groundwater or oil) || Local effect|| ≤ 55 mm/yr | |||
|- | |||
| Earthquake-induced vibration || Local effect | |||
|- | |||
! colspan="3" style="background:lightgray" | Departure from geoid | |||
|- | |||
| Shifts in hydrosphere, aesthenosphere, core-mantle interface || Local effect | |||
|- | |||
| Shifts in earth's rotation, axis of spin, and precession of equinox || Eustatic | |||
|- | |||
| External gravitational changes || Eustatic | |||
|- | |||
| Evaporation and precipitation (if due to a long-term pattern) || Local effect | |||
|} | |||
Due to these uncertainties, some scientists - including the originators of the hypothesis, Robert DeConto and David Pollard - have suggested that the best way to resolve the question would be to precisely determine sea level rise during the ].<ref name="Gilford2020" /> MICI can be effectively ruled out if SLR at the time was lower than {{cvt|4|m|ft|frac=2}}, while it is very likely if the SLR was greater than {{cvt|6|m|ft|frac=2}}.<ref name="Gilford2020">{{cite journal |last1=Gilford |first1=Daniel M. |last2=Ashe |first2=Erica L. |last3=DeConto |first3=Robert M. |last4=Kopp |first4=Robert E. |last5=Pollard |first5=David |last6=Rovere |first6=Alessio |date=5 October 2020 |title=Could the Last Interglacial Constrain Projections of Future Antarctic Ice Mass Loss and Sea-Level Rise? |url=https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2019JF005418 |journal=Journal of Geophysical Research: Earth Surface |volume=124 |issue=7 |pages=1899–1918 |doi=10.1029/2019JF005418 |bibcode=2020JGRF..12505418G |via=American Geophysical Union|hdl=10278/3749063 |hdl-access=free }}</ref> As of 2023, the most recent analysis indicates that the Last Interglacial SLR is unlikely to have been higher than {{cvt|2.7|m|ft|frac=2}},<ref name="Dumitru2023" /> as higher values in other research, such as {{cvt|5.7|m|ft|frac=2}},<ref>{{cite journal |last1=Barnett |first1=Robert L. |last2=Austermann |first2=Jacqueline |last3=Dyer |first3=Blake |last4=Telfer |first4=Matt W. |last5=Barlow |first5=Natasha L. M. |last6=Boulton |first6=Sarah J. |last7=Carr |first7=Andrew S. |last8=Creel |first8=Roger |date=15 September 2023 |title=Constraining the contribution of the Antarctic Ice Sheet to Last Interglacial sea level |journal=Science Advances |volume=9 |issue=27 |pages=eadf0198 |doi=10.1126/sciadv.adf0198 |pmid=37406130 |pmc=10321746 |bibcode=2023SciA....9F.198B }}</ref> appear inconsistent with the new ] data from ] and the known history of the Greenland Ice Sheet.<ref name="Dumitru2023">{{cite journal |last1=Dumitru |first1=Oana A. |last2=Dyer |first2=Blake |last3=Austermann |first3=Jacqueline |last4=Sandstrom |first4=Michael R. |last5=Goldstein |first5=Steven L. |last6=D'Andrea |first6=William J. |last7=Cashman |first7=Miranda |last8=Creel |first8=Roger |last9=Bolge |first9=Louise |last10=Raymo |first10=Maureen E. |date=15 September 2023 |title=Last interglacial global mean sea level from high-precision U-series ages of Bahamian fossil coral reefs |journal=Quaternary Science Reviews |volume=318 |page=108287 |doi=10.1016/j.quascirev.2023.108287 |doi-access=free |bibcode=2023QSRv..31808287D }}</ref> | |||
== Past changes in sea level == | |||
] | |||
=== |
=== Post-2100 sea level rise === | ||
] | |||
For generations, geologists have been trying to explain the obvious cyclicity of ] deposits observed everywhere we look. The prevailing theories hold that this cyclicity primarily represents the response of depositional processes to the rise and fall of sea level. In the rock record, geologists see times when sea level was astoundingly low alternating with times when sea level was much higher than today, and these anomalies often appear worldwide. For instance, during the depths of the last ] 18,000 years ago when hundreds of thousands of cubic miles of ice was stacked up on the continents as glaciers, sea level was 390 feet (120 m) lower, locations that today support coral reefs were left high and dry, and coastlines were miles farther basinward from the present-day coastline. It was during this time of very low sea level that there was a dry land connection between Asia and Alaska over which humans are believed to have migrated to North America (see ]). | |||
Even if the temperature stabilizes, significant sea-level rise (SLR) will continue for centuries,<ref name="nrccon">{{cite book |author=National Research Council |title=Advancing the Science of Climate Change |publisher=The National Academies Press |year=2010 |isbn=978-0-309-14588-6 |location=Washington, DC |page=245 |chapter=7 Sea Level Rise and the Coastal Environment |doi=10.17226/12782 |access-date=2011-06-17 |chapter-url=http://books.nap.edu/openbook.php?record_id=12782&page=245 |archive-date=2015-08-13 |archive-url=https://web.archive.org/web/20150813203235/http://books.nap.edu/openbook.php?record_id=12782 |url-status=live }}</ref> consistent with ] of sea level rise.<ref name="ipcc13" />{{rp|1189}} This is due to the high level of inertia in the carbon cycle and the climate system, owing to factors such as the slow diffusion of heat into the ], leading to a longer climate response time.<ref>{{Cite journal |last1=Hansen |first1=J. |last2=Russell |first2=G. |last3=Lacis |first3=A. |last4=Fung |first4=I. |last5=Rind |first5=D. |last6=Stone |first6=P. |date=1985-08-30 |title=Climate Response Times: Dependence on Climate Sensitivity and Ocean Mixing |url=https://pubs.giss.nasa.gov/docs/1985/1985_Hansen_ha09600g.pdf |journal=Science |language=en |volume=229 |issue=4716 |pages=857–859 |doi=10.1126/science.229.4716.857 |pmid=17777925 |bibcode=1985Sci...229..857H |issn=0036-8075 |archive-url=https://web.archive.org/web/20210327184018/https://pubs.giss.nasa.gov/docs/1985/1985_Hansen_ha09600g.pdf |archive-date=March 27, 2021 |via=NASA}}</ref> A 2018 paper estimated that sea level rise in 2300 would increase by a median of 20 cm (8 in) for every five years {{CO2}} emissions increase before peaking. It shows a 5% likelihood of a {{cvt|1|m|ft|frac=2}} increase due to the same. The same estimate found that if the temperature stabilized below {{convert|2|C-change|F-change}}, 2300 sea level rise would still exceed {{cvt|1.5|m|ft|frac=2}}. Early ] and slowly falling temperatures could limit it to {{cvt|70–120|cm|in|frac=2}}.<ref>{{Cite journal |last1=Mengel |first1=Matthias |last2=Nauels |first2=Alexander |last3=Rogelj |first3=Joeri |last4=Schleussner |first4=Carl-Friedrich |date=20 February 2018 |title=Committed sea-level rise under the Paris Agreement and the legacy of delayed mitigation action |journal=Nature Communications |volume=9 |issue=1 |page=601 |doi=10.1038/s41467-018-02985-8 |pmid=29463787 |pmc=5820313 |bibcode=2018NatCo...9..601M}}</ref> | |||
However, for the past 6000 years (long before mankind started keeping written records) the world's sea level has been gradually approaching the level we see today. During the previous interglacial about 120,000 years ago, sea level was for a short time about 6 m higher than today, as evidenced by wave-cut notches along cliffs in the ]. There are also Pleistocene ] left stranded about 3 meters above today's sea level along the southwestern coastline of West Caicos Island in the British West Indies. These once-submerged reefs and nearby paleo-beach deposits are silent testament that sea level spent enough time at that higher level to allow the reefs to grow (exactly where this extra sea water came from—Antarctica or Greenland—has not yet been determined). Abundant similar evidence of geologically recent sea level positions can be found around the world. | |||
By 2021, the ] was able to provide estimates for sea level rise in 2150. Keeping warming to 1.5{{Nbsp}}°C under the SSP1-1.9 scenario would result in sea level rise in the 17–83% range of {{cvt|37–86|cm|in|frac=2}}. In the SSP1-2.6 pathway the range would be {{cvt|46–99|cm|in|frac=2}}, for SSP2-4.5 a {{cvt|66–133|cm|in|frac=2}} range by 2100 and for SSP5-8.5 a rise of {{cvt|98–188|cm|in|frac=2}}. It stated that the "low-confidence, high impact" projected {{cvt|0.63-1.60|m|ft|frac=2}} mean sea level rise by 2100, and that by 2150, the total sea level rise in his scenario would be in the range of {{cvt|0.98 - 4.82|m|ft|frac=2}} by 2150.<ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1302}} AR6 also provided lower-confidence estimates for year 2300 sea level rise under SSP1-2.6 and SSP5-8.5 with various impact assumptions. In the best case scenario, under SSP1-2.6 with no ice sheet acceleration after 2100, the estimate was only {{Convert|0.8 - 2.0|m|ft}}. In the worst estimated scenario, SSP-8.5 with ice cliff instability, the projected range for total sea level rise was {{Convert|9.5 - 16.2|m|ft}} by the year 2300.<ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1306}} | |||
===Estimates=== | |||
See IPCC TAR, figure 11.4{{ref|www.grida.no.282}} for a graph of sea level changes over the past 140 000 years. | |||
Projections for subsequent years are more difficult. In 2019, when 22 experts on ice sheets were asked to estimate 2200 and 2300 SLR under the 5{{Nbsp}}°C warming scenario, there were 90% ]s of −{{cvt|10|cm|in|frac=2}} to {{cvt|740|cm|ft|frac=2}} and −{{cvt|9|cm|in|frac=2}} to {{cvt|970|cm|ft|frac=2}}, respectively. (Negative values represent the extremely low probability of large climate change-induced increases in ] greatly elevating ice sheet ].)<ref name="PNAS22">{{cite journal |last1=Bamber |first1=Jonathan L. |last2=Oppenheimer |first2=Michael |last3=Kopp |first3=Robert E. |last4=Aspinall |first4=Willy P. |last5=Cooke |first5=Roger M. |date=May 2019 |title=Ice sheet contributions to future sea-level rise from structured expert judgment |journal=Proceedings of the National Academy of Sciences |volume=116 |issue=23 |pages=11195–11200 |bibcode=2019PNAS..11611195B |doi=10.1073/pnas.1817205116 |pmc=6561295 |pmid=31110015 |doi-access=free}}</ref> In 2020, 106 experts who contributed to 6 or more papers on sea level estimated median {{cvt|118|cm|in|frac=2}} SLR in the year 2300 for the low-warming RCP2.6 scenario and the median of {{cvt|329|cm|in|frac=2}} for the high-warming RCP8.5. The former scenario had the 5%–95% confidence range of {{cvt|24–311|cm|in|frac=2}}, and the latter of {{cvt|88–783|cm|in|frac=2}}.<ref name="Horton2020" /> | |||
* Sea-level rise estimates from ] altimetry since 1992 (about 2.8 mm/yr) exceed those from tide gauges. It is unclear whether this represents an increase over the last decades; variability; true differences between satellites and tide gauges; or problems with satellite ]. | |||
* Measurements have detected no significant acceleration in the recent rate of sea level rise. | |||
* Based on ] data, the rate of global average sea level rise during the 20th century lies in the range 0.8 to 3.3 mm/yr, with an average rate of 1.8 mm/yr.{{ref|www.grida.no.283}} | |||
* Recent studies of Roman wells in ] and of Roman '']e'' in Italy indicate that sea level stayed fairly constant from a few hundred years AD to a few hundred years ago. | |||
* Based on geological data, global average sea level may have risen at an average rate of about 0.5 mm/yr over the last 6 000 years and at an average rate of 0.1 to 0.2 mm/yr over the last 3,000 years. | |||
* Since the ] about 20 000 years ago, sea level has risen by over 120 m (averaging 6 mm/yr) as a result of melting of major ice sheets. A rapid rise took place between 15 000 and 6 000 years ago at an average rate of 10 mm/yr which accounted for 90 m of the rise; thus in the period since 20 000 years BP (excluding the rapid rise from 15-6 kyr BP) the average rate was 3 mm/yr. | |||
* A significant event was Meltwater Pulse 1A (mwp-1A), when sea level rose approximately 20 m over a 500 year period about 14 200 years ago. This is a rate of about 40 mm/yr. Recent studies suggest the primary source was meltwater from the ], perhaps causing the south-to-north cold pulse marked by the ] ], which preceded the ] ]. | |||
] will also have an effect on local sea levels).|alt=A map showing major SLR impact in south-east Asia, Northern Europe and the East Coast of the US]] | |||
== Future sea level rise == | |||
Tide gauges and satellite altimetry suggest an increase in sea level of 1.5-3 mm/yr over the past 100 years. The IPCC predicts that by 2100, ] will lead to a sea level rise of 110 to 880 mm (details below). Rejecting some IPCC assumptions, Mörner (2004) has argued that sea level rise will not exceed 200 mm, within a range of either +100±100 mm or +50±150 mm depending on assumptions. | |||
After 500 years, sea level rise from thermal expansion alone may have reached only half of its eventual level - likely within ranges of {{cvt|0.5-2|m|ft|frac=2}}.<ref name="solomon">{{cite journal |last1=Solomon |first1=Susan |last2=Plattner |first2=Gian-Kasper |last3=Knutti |first3=Reto |last4=Friedlingstein |first4=Pierre |date=10 February 2009 |title=Irreversible climate change due to carbon dioxide emissions |journal=Proceedings of the National Academy of Sciences |volume=106 |issue=6 |pages=1704–1709 |bibcode=2009PNAS..106.1704S |doi=10.1073/pnas.0812721106 |pmc=2632717 |pmid=19179281 |doi-access=free}}</ref> Additionally, ] of Greenland and Antarctica ice sheets are likely to play a larger role over such timescales.<ref name="Pattyn-2018">{{cite journal |last1=Pattyn |first1=Frank |last2=Ritz |first2=Catherine |last3=Hanna |first3=Edward |last4=Asay-Davis |first4=Xylar |last5=DeConto |first5=Rob |last6=Durand |first6=Gaël |last7=Favier |first7=Lionel |last8=Fettweis |first8=Xavier |last9=Goelzer |first9=Heiko |last10=Golledge |first10=Nicholas R. |last11=Kuipers Munneke |first11=Peter |date=12 November 2018 |title=The Greenland and Antarctic ice sheets under 1.5 °C global warming |url=https://dipot.ulb.ac.be/dspace/bitstream/2013/278021/3/ReviewOnePointFive_v7.pdf |journal=Nature Climate Change |volume=8 |issue=12 |pages=1053–1061 |bibcode=2018NatCC...8.1053P |doi=10.1038/s41558-018-0305-8 |first13=Sophie |last13=Nowicki |s2cid=91886763 |last12=Lenaerts |first18=Michiel |last14=Payne |last18=van den Broeke |first17=Luke D. |last17=Trusel |first16=Hélène |last16=Seroussi |first15=Alexander |last15=Robinson |first14=Antony J. |first12=Jan T. M. |access-date=31 October 2019 |archive-date=7 March 2020 |archive-url=https://web.archive.org/web/20200307041816/https://dipot.ulb.ac.be/dspace/bitstream/2013/278021/3/ReviewOnePointFive_v7.pdf |url-status=live }}</ref> Ice loss from ] is likely to dominate very long-term SLR, especially if the warming exceeds {{convert|2|C-change|F-change}}. Continued carbon dioxide emissions from fossil fuel sources could cause additional tens of metres of sea level rise, over the next millennia.<ref>{{Cite journal |last1=Clark |first1=Peter U. |last2=Shakun |first2=Jeremy D. |last3=Marcott |first3=Shaun A. |last4=Mix |first4=Alan C. |last5=Eby |first5=Michael |date=April 2016 |title=Consequences of twenty-first-century policy for multi-millennial climate and sea-level change |url=https://ir.library.oregonstate.edu/concern/articles/mk61rj62n |journal=Nature Climate Change |language=en |volume=6 |issue=4 |pages=360–369 |doi=10.1038/nclimate2923 |bibcode=2016NatCC...6..360C |issn=1758-6798 |archive-url=https://web.archive.org/web/20200711054610/https://ir.library.oregonstate.edu/downloads/5999n523k |archive-date=July 11, 2020 |via=Oregon State University}}</ref> Burning of all fossil fuels on Earth is sufficient to melt the entire Antarctic ice sheet, causing about {{Cvt|58|m|ft}} of sea level rise.<ref>{{cite journal |last1=Winkelmann |first1=Ricarda |author1-link=Ricarda Winkelmann |last2=Levermann |first2=Anders |last3=Ridgwell |first3=Andy |last4=Caldeira |first4=Ken |date=11 September 2015 |title=Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet |journal=Science Advances |volume=1 |issue=8 |pages=e1500589 |bibcode=2015SciA....1E0589W |doi=10.1126/sciadv.1500589 |pmc=4643791 |pmid=26601273}}</ref> | |||
These sea level rises could lead to difficulties for shore-based communities: for example, many major cities such as ] already need storm-surge defences, and would need more if sea level rose. TAR chapter 11{{ref|www.grida.no.284}}. | |||
Year 2021 IPCC estimates for the amount of sea level rise over the next 2,000 years project that: | |||
Future sea level rise, like the recent rise, is not expected to be globally uniform. Some regions show a sea level rise substantially more than the global average (in many cases of more than twice the average), and others a sea level fall {{ref|www.grida.no.285}}. However, models disagree as to the likely pattern of sea level change {{ref|www.grida.no.286}}. | |||
* At a warming peak of {{convert|1.5|C-change|F-change}}, global sea levels would rise {{cvt|2-3|m|ft|frac=2}} | |||
* At a warming peak of {{convert|2|C-change|F-change}}, sea levels would rise {{cvt|2-6|m|ft|frac=2}} | |||
* At a warming peak of {{convert|5|C-change|F-change}}, sea levels would rise {{cvt|19-22|m|ft|frac=2}}<ref name="IPCC_2021_WGI_SPM" />{{rp|SPM-21}} | |||
Sea levels would continue to rise for several thousand years after the ceasing of emissions, due to the slow nature of climate response to heat. The same estimates on a timescale of 10,000 years project that: | |||
=== IPCC results === | |||
* At a warming peak of {{convert|1.5|C-change|F-change}}, global sea levels would rise {{cvt|6-7|m|ft|frac=2}} | |||
* At a warming peak of {{convert|2|C-change|F-change}}, sea levels would rise {{cvt|8-13|m|ft|frac=2}} | |||
* At a warming peak of {{convert|5|C-change|F-change}}, sea levels would rise {{cvt|28-37|m|ft|frac=2}}<ref name="IPCC AR6 WG1 Ch.9" />{{rp|1306}} | |||
== Measurements == | |||
The results from the IPCC ] sea level chapter (convening authors ] and ]) are given below. | |||
Variations in the amount of water in the oceans, changes in its volume, or varying land elevation compared to the sea surface can drive sea level changes. Over a consistent time period, assessments can attribute contributions to sea level rise and provide early indications of change in trajectory. This helps to inform adaptation plans.<ref>{{Cite web |title=2022 Sea Level Rise Technical Report |url=https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html#step4 |access-date=2022-02-22 |website=oceanservice.noaa.gov |language=EN-US |archive-date=2022-11-29 |archive-url=https://web.archive.org/web/20221129070303/https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html#step4 |url-status=live }}</ref> The different techniques used to measure changes in sea level do not measure exactly the same level. Tide gauges can only measure relative sea level. ]s can also measure absolute sea level changes.<ref name="Rovere-2016-2">{{cite journal |last1=Rovere |first1=Alessio |last2=Stocchi |first2=Paolo |last3=Vacchi |first3=Matteo |date=2 August 2016 |title=Eustatic and Relative Sea Level Changes |journal=Current Climate Change Reports |volume=2 |issue=4 |pages=221–231 |doi=10.1007/s40641-016-0045-7 |bibcode=2016CCCR....2..221R |s2cid=131866367 |doi-access=free}}</ref> To get precise measurements for sea level, researchers studying the ice and oceans factor in ongoing ]. They look in particular at ], and the ] and ].<ref name="WCRP2018" /> | |||
=== Satellites === | |||
] continued the sea surface measurements started by TOPEX/Poseidon. It was followed by the ] on ], and by ].]] | |||
Since the launch of ] in 1992, an overlapping series of ] has been continuously recording the sea level and its changes.<ref>{{cite web |title=Ocean Surface Topography from Space |url=http://sealevel.jpl.nasa.gov/missions/topex/ |archive-url=https://web.archive.org/web/20110722010847/http://sealevel.jpl.nasa.gov/missions/topex/ |archive-date=2011-07-22 |publisher=NASA/JPL}}</ref> These satellites can measure the hills and valleys in the sea caused by currents and detect trends in their height. To measure the distance to the sea surface, the satellites send a microwave pulse towards Earth and record the time it takes to return after reflecting off the ocean's surface. ]s correct the additional delay caused by ] in the ]. Combining these data with the location of the spacecraft determines the sea-surface height to within a few centimetres.<ref>{{Cite web |title=Jason-3 Satellite – Mission |url=https://www.nesdis.noaa.gov/jason-3/mission.html |access-date=2018-08-22 |website=www.nesdis.noaa.gov |archive-date=2019-09-06 |archive-url=https://web.archive.org/web/20190906144644/https://www.nesdis.noaa.gov/jason-3/mission.html |url-status=live }}</ref> These satellite measurements have estimated rates of sea level rise for 1993–2017 at {{convert|3.0|±|0.4|mm|frac=64|in}} per year.<ref name="Nerem-2018">{{cite journal |last1=Nerem |first1=R. S. |last2=Beckley |first2=B. D. |last3=Fasullo |first3=J. T. |last4=Hamlington |first4=B. D. |last5=Masters |first5=D. |last6=Mitchum |first6=G. T. |date=27 February 2018 |title=Climate-change–driven accelerated sea-level rise detected in the altimeter era |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=115 |issue=9 |pages=2022–2025 |bibcode=2018PNAS..115.2022N |doi=10.1073/pnas.1717312115 |pmc=5834701 |pmid=29440401 |doi-access=free}}</ref> | |||
{| class="wikitable" | |||
! IPCC change factors 1990-2100 | |||
! IS92a prediction | |||
! SRES prediction | |||
|- | |||
| Thermal expansion || 110 to 430 mm | |||
|- | |||
| Glaciers || 0.01 to 0.23 m {{ref|www.grida.no.287}}<br>(or 0.05 to 0.11 m){{ref|www.grida.no.288}} | |||
|- | |||
| Greenland ice || –20 to 90 mm | |||
|- | |||
| Antarctic ice || –170 to 20 mm | |||
|- | |||
| Terrestrial storage || –83 to 30 mm | |||
|- | |||
| Ongoing contributions from ice sheets in response to past climate change || 0 to 0.05 m | |||
|- | |||
| Thawing of permafrost || 0 to 5 mm | |||
|- | |||
| Deposition of sediment || not specified | |||
|- | |||
! Total global-average sea level rise<br>''(IPCC result, not sum of above)'' {{ref|www.grida.no.289}} !! 110 to 770 mm !! 90 to 880 mm <br>(central value of 480 mm) | |||
|} | |||
Satellites are useful for measuring regional variations in sea level. An example is the substantial rise between 1993 and 2012 in the western tropical Pacific. This sharp rise has been linked to increasing ]. These occur when the ] (PDO) and the ] (ENSO) change from one state to the other.<ref>{{cite journal |last1=Merrifield |first1=Mark A. |last2=Thompson |first2=Philip R. |last3=Lander |first3=Mark |date=July 2012 |title=Multidecadal sea level anomalies and trends in the western tropical Pacific |journal=Geophysical Research Letters |volume=39 |issue=13 |pages=n/a |bibcode=2012GeoRL..3913602M |doi=10.1029/2012gl052032 |s2cid=128907116}}</ref> The PDO is a basin-wide climate pattern consisting of two phases, each commonly lasting 10 to 30 years. The ENSO has a shorter period of 2 to 7 years.<ref>{{cite journal |last1=Mantua |first1=Nathan J. |last2=Hare |first2=Steven R. |last3=Zhang |first3=Yuan |last4=Wallace |first4=John M. |last5=Francis |first5=Robert C. |date=June 1997 |title=A Pacific Interdecadal Climate Oscillation with Impacts on Salmon Production |journal=Bulletin of the American Meteorological Society |volume=78 |issue=6 |pages=1069–1079 |bibcode=1997BAMS...78.1069M |doi=10.1175/1520-0477(1997)078<1069:APICOW>2.0.CO;2 |doi-access=free}}</ref> | |||
The sum of these components indicates a rate of eustatic sea level rise (corresponding to a change in ocean volume) from 1910 to 1990 ranging from –0.8 to 2.2 mm/yr, with a central value of 0.7 mm/yr. The upper bound is close to the observational upper bound (2.0 mm/yr), but the central value is less than the observational lower bound (1.0 mm/yr), i.e., the sum of components is biased low compared to the observational estimates. The sum of components indicates an acceleration of only 0.2 (mm/yr)/century, with a range from –1.1 to +0.7 (mm/yr)/century, consistent with observational finding of no acceleration in sea level rise during the ]. The estimated rate of sea level rise from anthropogenic climate change from 1910 to 1990 (from modelling studies of thermal expansion, glaciers and ice sheets) ranges from 0.3 to 0.8 mm/yr. It is very likely that ] warming has contributed significantly to the observed sea level rise, through thermal expansion of sea water and widespread loss of land ice {{ref|www.grida.no.290}}. | |||
=== Tide gauges === | |||
A common perception is that the rate of sea level rise should have accelerated during the latter half of the ]. The tide gauge data for the ] show no significant acceleration. We have obtained estimates based on AOGCMs for the terms directly related to anthropogenic climate change in the ], i.e., thermal expansion, ice sheets, glaciers and ice caps... The total computed rise {{ref|www.grida.no.291}} indicates an acceleration of only 0.2 (mm/yr)/century, with a range from -1.1 to +0.7 (mm/yr)/century, consistent with observational finding of no acceleration in sea level rise during the ]. The sum of terms not related to recent climate change is -1.1 to +0.9 mm/yr (i.e., excluding thermal expansion, glaciers and ice caps, and changes in the ice sheets due to 20th century climate change). This range is less than the observational lower bound of sea level rise. Hence it is very likely that these terms alone are an insufficient explanation, implying that 20th century climate change has made a contribution to 20th century sea level rise {{ref|www.grida.no.292}}. | |||
{{Webarchive|url=https://web.archive.org/web/20190228065905/https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level |date=2019-02-28 }} ''NOAA Climate'', 19 November 2019.</ref>]] | |||
The global network of ]s is the other important source of sea-level observations. Compared to the satellite record, this record has major spatial gaps but covers a much longer period.<ref name="Rhein-2013">{{Cite book |last1=Rhein |first1=Monika |title=IPCC AR5 WGI |last2=Rintoul |first2=Stephan |publisher=Cambridge University Press |year=2013 |location=New York |page=285 |chapter=Observations: Ocean |author-link1=Monika Rhein |access-date=2018-08-26 |chapter-url=https://ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter03_FINAL.pdf |archive-url=https://web.archive.org/web/20180613012554/https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter03_FINAL.pdf |archive-date=2018-06-13}}</ref> Coverage of tide gauges started mainly in the ]. Data for the ] remained scarce up to the 1970s.<ref name="Rhein-2013" /> The longest running sea-level measurements, NAP or ] were established in 1675, in ].<ref>{{cite web |title=Other Long Records not in the PSMSL Data Set |url=http://www.psmsl.org/data/longrecords/ |access-date=11 May 2015 |publisher=PSMSL |archive-date=20 April 2020 |archive-url=https://web.archive.org/web/20200420160218/https://www.psmsl.org/data/longrecords/ |url-status=live }}</ref> Record collection is also extensive in ]. They include measurements by ], an amateur meteorologist, beginning in 1837. Lempriere established a sea-level benchmark on a small cliff on the ] near the ] convict settlement in 1841.<ref>{{cite journal |last=Hunter |first=John |author2=R. Coleman |author3=D. Pugh |date=2003 |title=The Sea Level at Port Arthur, Tasmania, from 1841 to the Present |url=https://figshare.com/articles/journal_contribution/22846694 |journal=Geophysical Research Letters |volume=30 |issue=7 |page=1401 |bibcode=2003GeoRL..30.1401H |doi=10.1029/2002GL016813 |s2cid=55384210}}</ref> | |||
==== Uncertainties and criticisms regarding IPCC results ==== | |||
* Tide records with a rate of 180 mm/century going back to the ] show no measurable acceleration throughout the late ] and first half of the ]. The IPCC attributes about 60 mm/century to melting and other eustatic processes, leaving a residual of 120 mm of ] rise to be accounted for. Global ocean temperatures by Levitus et al are in accord with coupled ocean/atmosphere modeling of greenhouse warming, with heat-related change of 30 mm. Melting of polar ice sheets at the upper limit of the IPCC estimates could close the gap, but severe limits are imposed by the observed perturbations in Earth rotation. (Munk 2002) | |||
* By the time of the IPCC TAR, attribution of sea level changes had a large unexplained gap between direct and indirect estimates of global sea level rise. Most direct estimates from tide gauges give 1.5–2.0 mm/yr, whereas indirect estimates based on the two processes responsible for global sea level rise, namely mass and volume change, are significantly below this range. Estimates of the volume increase due to ocean warming give a rate of about 0.5 mm/yr and the rate due to mass increase, primarily from the melting of continental ice, is thought to be even smaller. One study confirmed tide gauge data is correct, and concluded there must be a continental source of 1.4 mm/yr of fresh water. (Miller 2004) | |||
* From (Douglas 2002): "In the last dozen years, published values of ] GSL rise have ranged from 1.0 to 2.4 mm/yr. In its Third Assessment Report, the IPCC discusses this lack of consensus at length and is careful not to present a best estimate of ] GSL rise. By design, the panel presents a snapshot of published analyses over the previous decade or so and interprets the broad range of estimates as reflecting the uncertainty of our knowledge of GSL rise. We disagree with the IPCC interpretation. In our view, values much below 2 mm/yr are inconsistent with regional observations of sea-level rise and with the continuing physical response of Earth to the most recent episode of deglaciation." | |||
* Nils-Axel Mörner, states: "All handling by IPCC of the Sea Level questions have been done in a way that cannot be accepted and that certainly not concur with modern knowledge of the mode and mechanism of sea level changes. ... It seems that the authors involved in were chosen not because of their deep knowledge in the subject, but rather because they should say what the climate model had predicted. This chapter has a low and unacceptable standard." {{ref|www.pog.su.se.293}} | |||
* The strong 1997-] El Niño caused regional and global sea level variations, including a temporary global increase of perhaps 20 mm. The IPCC TAR's examination of satellite trends says '' the major 1997/] El Niño-Southern Oscillation (ENSO) event could bias the above estimates of sea level rise and also indicate the difficulty of separating long-term trends from climatic variability'' {{ref|www.grida.no.294}}. | |||
Together with satellite data for the period after 1992, this network established that global mean sea level rose {{Convert|19.5|cm|in|abbr=on}} between 1870 and 2004 at an average rate of about 1.44 mm/yr. (For the 20th century the average is 1.7 mm/yr.)<ref name="church2">{{cite journal |author=Church, J.A. |author2=White, N.J. |date=2006 |title=20th century acceleration in global sea-level rise |journal=Geophysical Research Letters |volume=33 |issue=1 |pages=L01602 |bibcode=2006GeoRL..33.1602C |citeseerx=10.1.1.192.1792 |doi=10.1029/2005GL024826 |s2cid=129887186}}</ref> By 2018, data collected by Australia's ] (CSIRO) had shown that the global mean sea level was rising by {{Convert|3.2|mm|in|abbr=on|frac=32}} per year. This was double the average 20th century rate.<ref>{{Cite web |title=Historical sea level changes: Last decades |url=http://www.cmar.csiro.au/sealevel/sl_hist_last_decades.html |access-date=2018-08-26 |website=www.cmar.csiro.au |archive-date=2020-03-18 |archive-url=https://web.archive.org/web/20200318220615/http://www.cmar.csiro.au/sealevel/sl_hist_last_decades.html |url-status=live }}</ref><ref>{{cite web |last=Neil |first=White |title=Historical Sea Level Changes |url=http://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html |access-date=25 April 2013 |publisher=CSIRO |archive-date=13 May 2020 |archive-url=https://web.archive.org/web/20200513230040/http://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html |url-status=live }}</ref> The 2023 ] report found further acceleration to 4.62 mm/yr over the 2013–2022 period.<ref name=WMO_20230421/> These observations help to check and verify predictions from climate change simulations. | |||
=== Glacier contribution === | |||
The results from Dyurgerov show a sharp increase in the contribution of mountain and subpolar glaciers to sea level rise since 1996 (0.5 mm/yr) to 1998 (2mm/yr) with an average of approx. 0.35 mm/yr since 1960. (Dyurgerov, Mark. 2002. Glacier Mass Balance and Regime: Data of Measurements and Analysis. INSTAAR Occasional Paper No. 55, ed. M. Meier and R. Armstrong. Boulder, CO: Institute of Arctic and Alpine Research, University of Colorado. | |||
Distributed by National Snow and Ice Data Center, Boulder, CO. A shorter discussion is at {{ref|nsidc.org.295}}) | |||
Of interest is also Arendt et al, (''Science'', 297, p. 382, July 2002) who estimate the contribution of Alaskan glaciers of 0.14±0.04 mm/yr between the mid 1950s to the mid 1990s increasing to 0.27 mm/yr in the middle and late 1990s. | |||
Regional differences are also visible in the tide gauge data. Some are caused by local sea level differences. Others are due to vertical land movements. In ], only some land areas are rising while the others are sinking. Since 1970, most tidal stations have measured higher seas. However sea levels along the northern ] have dropped due to ].<ref>{{cite web |date=18 November 2021 |title=Global and European sea level rise |url=https://www.eea.europa.eu/ims/global-and-european-sea-level-rise |website=European Environment Agency |access-date=10 October 2022 |archive-date=27 August 2023 |archive-url=https://web.archive.org/web/20230827001932/https://www.eea.europa.eu/ims/global-and-european-sea-level-rise |url-status=live }}</ref> | |||
=== Greenland contribution === | |||
Krabill ''et al.'' (''Science'', Vol 289, Issue 5478, 428-430, ] ]) estimate a net contribution from Greenland to be at least 0.13 mm/yr in the 1990s. Joughin ''et al.'' (''Nature'', Vol 432, p608, ]) have measured a doubling of the speed of Jacobshavn Isbrae between 1997 and 2003. This is Greenland's largest outlet glacier and drains 6.5% of the ice sheet, and is thought to be responsible for increasing the rate of sea level rise by about 0.06 millimeters per year, or roughly 4 percent of the ] rate of sea level increase. {{ref|www.spaceref.com.296}} In 2004, Rignot ''et al.'' (''Geophysical Research Letters'', v31, L10401) estimated a contribution of 0.04±0.01 mm/yr to sea level rise from southeast Greenland. | |||
===Past sea level rise=== | |||
In July 2005 it was reported {{ref|news.independent.co.uk.297}} that the Kangerdlugssuaq glacier, on Greenland's east coast, was moving towards the sea three times faster than a decade earlier. Kangerdlugssuaq is around 1000 m thick, 7.2 km (4.5 ]) wide, and drains about 4% of the ice from the Greenland ice sheet. Measurements of Kangerdlugssuaq in 1988 and 1996 showed it moving at between 5 and 6 km/yr (3.1 to 3.7 miles/yr) (in 2005 it was moving at 14 km/yr (8.7 miles/yr). | |||
{{Main|Past sea level|Sea level#Change|Marine transgression}} | |||
If the entire Greenland ice sheet were to melt (which is estimated to take at least 1000 years), sea levels would rise up to 7 metres. | |||
]]]An understanding of ] is an important guide to where current changes in sea level will end up. In the recent geological past, thermal expansion from increased temperatures and changes in land ice are the dominant reasons of sea level rise. The last time that the Earth was {{convert|2|C-change|F-change}} warmer than pre-industrial temperatures was 120,000 years ago. This was when warming due to ] (changes in the amount of sunlight due to slow changes in the Earth's orbit) caused the ] ]. Sea levels during that warmer interglacial were at least {{Convert|5|m|ft|abbr=on|}} higher than now.<ref>{{Cite web |date=2019-08-30 |title=Scientists discover evidence for past high-level sea rise |url=https://phys.org/news/2019-08-scientists-evidence-high-level-sea.html |access-date=2019-09-07 |website=phys.org |language=en-us |archive-date=2019-12-13 |archive-url=https://web.archive.org/web/20191213220151/https://phys.org/news/2019-08-scientists-evidence-high-level-sea.html |url-status=live }}</ref> The Eemian warming was sustained over a period of thousands of years. The size of the rise in sea level implies a large contribution from the Antarctic and Greenland ice sheets.<ref name="ipcc13" />{{rp|1139}} Levels of atmospheric carbon dioxide of around 400 ] (similar to 2000s) had increased temperature by over {{convert|2-3|C-change|F-change}} around three million years ago. This temperature increase eventually melted one third of Antarctica's ice sheet, causing sea levels to rise 20 meters above the preindustrial levels.<ref>{{Cite web |title=Present CO2 levels caused 20-metre-sea-level rise in the past |url=https://www.nioz.nl/en/news/present-co2-levels-caused-20-metre-sea-level-rise-in-the-past |publisher=Royal Netherlands Institute for Sea Research |access-date=2020-02-03 |archive-date=2020-08-01 |archive-url=https://web.archive.org/web/20200801030150/https://www.nioz.nl/en/news/present-co2-levels-caused-20-metre-sea-level-rise-in-the-past |url-status=live }}</ref> | |||
Since the ], about 20,000 years ago, sea level has risen by more than {{Convert|125|m|ft|-1}}. Rates vary from less than 1 mm/year during the pre-industrial era to 40+ mm/year when major ice sheets over Canada and Eurasia melted. ] are periods of fast sea level rise caused by the rapid disintegration of these ice sheets. The rate of sea level rise started to slow down about 8,200 years before today. Sea level was almost constant for the last 2,500 years. The recent trend of rising sea level started at the end of the 19th or beginning of the 20th century.<ref>{{cite journal |last1=Lambeck |first1=Kurt |last2=Rouby |first2=Hélène |last3=Purcell |first3=Anthony |last4=Sun |first4=Yiying |last5=Sambridge |first5=Malcolm |date=28 October 2014 |title=Sea level and global ice volumes from the Last Glacial Maximum to the Holocene |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=111 |issue=43 |pages=15296–15303 |bibcode=2014PNAS..11115296L |doi=10.1073/pnas.1411762111 |pmc=4217469 |pmid=25313072 |doi-access=free}}</ref> | |||
=== Polar ice === | |||
The sea level could rise above its current level if more polar ice melts. However, compared to the heights of the ice ages, today there are very few continental ice sheets remaining to be melted. It is estimated that Antarctica, if fully melted, would contribute more than 60 metres of sea level rise and Greenland would contribute more than 7 metres. Small glaciers and ice caps might contribute about 0.5 metres; this number is in the uncertainty of the estimates from Antarctica or Greenland but could be expected to be fast (within the coming century) whereas Greenland would be slow (perhaps 1500 years to fully deglaciate at the fastest likely rate) and Antarctica even slower {{ref|www.grida.no.298}}. | |||
== Causes == | |||
In 2002, Rignot and Thomas (''Science'', v297, 1502-1506, 2002) found that the West Antarctic and Greenland ice sheets were losing mass, while the East Antarctic ice sheet was probably in balance (although they could not determine the sign of the mass balance for The East Antarctic ice sheet). Kwok and Comiso (''J. Climate'', v15, 487-501, 2002) also discovered that temperature and pressure anomalies around West Antarctica and on the other side of the Antarctic Peninsula correlate with recent ] events. | |||
] | |||
=== Effects of climate change === | |||
In 2004 Rignot et al. (''Geophysical Research Letters'', v31, L10401) estimated a contribution of 0.04±0.01 mm/yr to sea level rise from South East Greenland. In the same year, Thomas et al. (Science, v306, 255-258, 2004) found evidence of an accelerated contribution to sea level rise from West Antarctica. The data showed that the Amundsen Sea sector of the West Antarctic Ice sheet was discharging 250 cubic kilometres of ice every year, which was 60% more than precipitation accumulation in the catchment areas. This alone was sufficient to raise sea level at 0.24 mm/yr. Further, thinning rates for the glaciers studied in 2002-] had increased over the values measured in the early 1990s. The bedrock underlying the glaciers was found to be hundreds of meters deeper than previously known, indicating exit routes for ice from further inland in the Byrd Subpolar Basin. Thus the West Antarctic ice sheet may not be as stable as has been supposed. | |||
{{See also|Effects of climate change}} | |||
The three main reasons why global warming causes sea levels to rise are ], water inflow from melting ice sheets and water inflow from glaciers. Other factors affecting sea level rise include changes in snow mass, and flow from terrestrial water storage, though the contribution from these is thought to be small.<ref name="WCRP2018"/> Glacier retreat and ocean expansion have dominated sea level rise since the start of the 20th century.<ref name="Mengel2016" /> Some of the losses from glaciers are offset when ] falls as snow, accumulates and over time forms glacial ice. If precipitation, surface processes and ice loss at the edge ] each other, sea level remains the same. Because of this precipitation began as water vapor evaporated from the ocean surface, ] can even increase ice build-up. However, this effect is not enough to fully offset ice losses, and sea level rise continues to accelerate.<ref name="AR6_WGII_Chapter9">Trisos, C. H., I. O. Adelekan, E. Totin, A. Ayanlade, J. Efitre, A. Gemeda, K. Kalaba, C. Lennard, C. Masao, Y. Mgaya, G. Ngaruiya, D. Olago, N. P. Simpson, and S. Zakieldeen 2022: {{Webarchive|url=https://web.archive.org/web/20221206082533/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter09.pdf|date=2022-12-06}}. In {{Webarchive|url=https://web.archive.org/web/20220228114918/https://www.ipcc.ch/report/ar6/wg2/|date=2022-02-28}} . Cambridge University Press, Cambridge, UK and New York, US, pp. 2043–2121 {{doi|10.1017/9781009325844.011}}.</ref><ref name="IMBIE2018" /><ref name="Rignot2019" /><ref name="Zwally2021" /> | |||
The contributions of the two large ice sheets, in ] and ], are likely to increase in the 21st century.<ref name="Mengel2016">{{cite journal |last1=Mengel |first1=Matthias |last2=Levermann |first2=Anders |last3=Frieler |first3=Katja |last4=Robinson |first4=Alexander |last5=Marzeion |first5=Ben |last6=Winkelmann |first6=Ricarda |title=Future sea level rise constrained by observations and long-term commitment |journal=Proceedings of the National Academy of Sciences |date=8 March 2016 |volume=113 |issue=10 |pages=2597–2602 |doi=10.1073/pnas.1500515113 |pmc=4791025 |pmid=26903648 |bibcode=2016PNAS..113.2597M |doi-access=free}}</ref> They store most of the land ice (~99.5%) and have a sea-level equivalent (SLE) of {{Convert|7.4|m|ftin|abbr=on}} for Greenland and {{Convert|58.3|m|ftin|abbr=on}} for Antarctica.<ref name="WCRP2018"/> Thus, melting of all the ice on Earth would result in about {{Convert|70|m|ftin|abbr=on}} of sea level rise,<ref>{{cite web |title=How would sea level change if all glaciers melted? |url=https://www.usgs.gov/faqs/how-would-sea-level-change-if-all-glaciers-melted |website=United States Geological Survey |access-date=15 January 2024 |archive-date=31 July 2023 |archive-url=https://web.archive.org/web/20230731120648/https://www.usgs.gov/faqs/how-would-sea-level-change-if-all-glaciers-melted |url-status=live }}</ref> although this would require at least 10,000 years and up to {{convert|10|C-change|F-change}} of global warming.<ref name="ArmstrongMcKay2022" /><ref name="ArmstrongMcKayExplainer" /> | |||
In 2005 it was reported that during 1992-], East Antarctica thickened at an average rate of about 18 mm/yr while West Antarctica showed an overall thinning of 9 mm/yr. associated with increased precipitation. A gain of this magnitude is enough to slow sea-level rise by 0.12±0.02 mm/yr. (Davis et al., ''Science 2005'') {{ref|refbot299}}. | |||
== |
=== Ocean heating === | ||
{{Main|Ocean heat content}} | |||
Based on the projected increases stated above, the IPCC TAR WG II report notes that current and future climate change would be expected to have a number of impacts, particularly on coastal systems {{ref|www.grida.no.300}}. Such impacts may include increased coastal erosion, higher storm-surge flooding, inhibition of primary production processes, more extensive coastal inundation, changes in surface water quality and groundwater characteristics, increased loss of property and coastal habitats, increased flood risk and potential loss of life, loss of nonmonetary cultural resources and values, impacts on agriculture and aquaculture through decline in soil and water quality, and loss of tourism, recreation, and transportation functions. | |||
] created by human-induced ].<ref name=NOAA_NASA_OHC_1957_>''Top 700 meters:'' {{cite web |last1=Lindsey |first1=Rebecca |last2=Dahlman |first2=Luann |title=Climate Change: Ocean Heat Content |url=https://www.climate.gov/news-features/understanding-climate/climate-change-ocean-heat-content |website=climate.gov |publisher=National Oceanic and Atmospheric Administration (NOAA) |archive-url=https://archive.today/20231029171303/https://www.climate.gov/news-features/understanding-climate/climate-change-ocean-heat-content |archive-date=29 October 2023 |date=6 September 2023 |url-status=live}} ● ''Top 2000 meters:'' {{cite web |title=Ocean Warming / Latest Measurement: December 2022 / 345 (± 2) zettajoules since 1955 |url=https://climate.nasa.gov/vital-signs/ocean-warming/ |website=NASA.gov |publisher=National Aeronautics and Space Administration |archive-url=https://web.archive.org/web/20231020033606/https://climate.nasa.gov/vital-signs/ocean-warming/ |archive-date=20 October 2023 |url-status=live}}</ref>]] | |||
The oceans store more than 90% of the extra heat added to the climate system by ] and act as a buffer against its effects.<ref>{{Cite journal |last1=Cheng |first1=Lijing |last2=Foster |first2=Grant |last3=Hausfather |first3=Zeke |last4=Trenberth |first4=Kevin E. |last5=Abraham |first5=John |date=2022 |title=Improved Quantification of the Rate of Ocean Warming |journal=Journal of Climate |volume=35 |issue=14 |pages=4827–4840 |bibcode=2022JCli...35.4827C |doi=10.1175/JCLI-D-21-0895.1 |doi-access=free}}</ref> This means that the same amount of heat that would increase the average world ocean temperature by {{convert|0.01|C-change|F-change}} would increase atmospheric temperature by approximately {{convert|10|C-change|F-change}}.<ref>{{cite journal |author1=Levitus, S. |author2=Boyer, T. |author3=Antonov, J. |title=Warming of the world ocean: 1955–2003 |year=2005 |journal=Geophysical Research Letters |volume=32 |issue=2 |doi=10.1029/2004GL021592 |doi-access=free|bibcode=2005GeoRL..32.2604L}}</ref> So a small change in the mean temperature of the ocean represents a very large change in the total heat content of the climate system. Winds and currents move heat into deeper parts of the ocean. Some of it reaches depths of more than {{Convert|2000|m|ft|sigfig=2|abbr=on}}.<ref>{{Cite web|url=https://www.scientificamerican.com/article/deep-ocean-waters-are-trapping-vast-stores-of-heat/|title=Deep Ocean Waters Are Trapping Vast Stores of Heat|last=Upton|first=John|date=2016-01-19|website=Scientific American|access-date=2019-02-01|archive-date=2020-06-30|archive-url=https://web.archive.org/web/20200630010341/https://www.scientificamerican.com/article/deep-ocean-waters-are-trapping-vast-stores-of-heat/|url-status=live}}</ref> | |||
When the ocean gains heat, ] and sea level rises. Warmer water and water under great pressure (due to depth) expand more than cooler water and water under less pressure.<ref name="ipcc13" />{{rp|1161}} Consequently, cold ] water will expand less than warm tropical water. Different climate models present slightly different patterns of ocean heating. So their projections do not agree fully on how much ocean heating contributes to sea level rise.<ref>{{Cite journal|last1=Kuhlbrodt|first1=T|last2=Gregory|first2=J.M.|date=2012|title=Ocean heat uptake and its consequences for the magnitude of sea level rise and climate change|journal=Geophysical Research Letters|volume=39|issue=18|pages=L18608|doi=10.1029/2012GL052952|bibcode=2012GeoRL..3918608K|s2cid=19120823|url=http://centaur.reading.ac.uk/28951/1/Kuhlbrodt_Gregory_GRL_2012.pdf|access-date=2019-10-31|archive-date=2020-07-31|archive-url=https://web.archive.org/web/20200731215122/http://centaur.reading.ac.uk/28951/1/Kuhlbrodt_Gregory_GRL_2012.pdf|url-status=live}}</ref> | |||
There is an implication that many of these impacts will be detrimental. The report does, however, note that owing to the great diversity of coastal environments; regional and local differences in projected relative sea level and climate changes; and differences in the resilience and adaptive capacity of ecosystems, sectors, and countries, the impacts will be highly variable in time and space and will not necessarily be negative in all situations. | |||
=== Ice loss on the Antarctic continent === | |||
To date, sea level changes have not been implicated in any substantial environmental, humanitarian, or economic losses. Previous claims have been made that parts of the island nations of ] was "sinking" as a result of sea level rise. However, subsequent reviews have suggested that the loss of land area was the result of erosion during and following the actions of 1997 cyclones Gavin, Hina, and Keli. {{ref|www.pacificislands.cc.301}} {{ref|outside.away.com.302}} The islands in questions were not populated. Reuters has reported other Pacific islands are facing a severe risk including Tegua island in ], data shows no net sea level rise. According to Patrick J. Michaels, "In fact, areas to the west such as Tuvalu show substantial declines in sea level over that period."{{ref|www.cnsnews.com.303}} <!-- Source needed: and the Cantaret Islands off ]. --> | |||
] | |||
] is Antarctica's largest. It is about the size of ] and up to several hundred metres thick.]] | |||
The large volume of ice on the Antarctic continent stores around 60% of the world's fresh water. Excluding ] this is 90%.<ref>{{cite web |title=Antarctic Factsheet |url=https://www.bas.ac.uk/science/science-and-society/education/antarctic-factsheet-geographical-statistics/ |publisher=British Antarctic Survey |access-date=15 January 2024 |archive-date=15 January 2024 |archive-url=https://web.archive.org/web/20240115190903/https://www.bas.ac.uk/science/science-and-society/education/antarctic-factsheet-geographical-statistics/ |url-status=live }}</ref> Antarctica is experiencing ice loss from coastal glaciers in the ] and some glaciers of ]. However it is gaining mass from the increased snow build-up inland, particularly in the East. This leads to contradicting trends.<ref name="Zwally2021" /><ref name="NASA2023" /> There are different satellite methods for measuring ice mass and change. Combining them helps to reconcile the differences.<ref name="IMBIE2012">{{Cite journal|last1=Shepherd|first1=Andrew|last2=Ivins|first2=Erik|date=2012|title=A Reconciled Estimate of Ice-Sheet Mass Balance|url=http://www.escholarship.org/uc/item/0vq404h7|journal=]|volume=338|issue=6111|pages=1183–1189|bibcode=2012Sci...338.1183S|doi=10.1126/science.1228102|pmid=23197528|collaboration=] team|hdl=2060/20140006608|s2cid=32653236|access-date=2020-11-10|archive-date=2023-01-23|archive-url=https://web.archive.org/web/20230123141116/https://escholarship.org/uc/item/0vq404h7|url-status=live}}</ref> However, there can still be variations between the studies. In 2018, a ] estimated average annual ice loss of 43 billion tons (Gt) across the entire continent between 1992 and 2002. This tripled to an annual average of 220 Gt from 2012 to 2017.<ref name="IMBIE2018">{{cite journal |title=Mass balance of the Antarctic Ice Sheet from 1992 to 2017 |journal=Nature |date=13 June 2018 |volume=558 |issue=7709 |pages=219–222 |doi=10.1038/s41586-018-0179-y |hdl=2268/225208 |pmid=29899482 |bibcode=2018Natur.558..219I |author1=IMBIE team |s2cid=49188002 |hdl-access=free}}</ref><ref>{{cite news |author=Scott K. Johnson |date=2018-06-13 |title=Latest estimate shows how much Antarctic ice has fallen into the sea |work=] |url=https://arstechnica.com/science/2018/06/latest-estimate-shows-how-much-antarctic-ice-has-fallen-into-the-sea |access-date=2018-06-15 |archive-date=2018-06-15 |archive-url=https://web.archive.org/web/20180615083459/https://arstechnica.com/science/2018/06/latest-estimate-shows-how-much-antarctic-ice-has-fallen-into-the-sea/ |url-status=live }}</ref> However, a 2021 analysis of data from four different research satellite systems (], ], ] and ]) indicated annual mass loss of only about 12 Gt from 2012 to 2016. This was due to greater ice gain in East Antarctica than estimated earlier.<ref name="Zwally2021" /> | |||
In the future, it is known that West Antarctica at least will continue to lose mass, and the likely future losses of sea ice and ], which block warmer currents from direct contact with the ice sheet, can accelerate declines even in East Antarctica.<ref name="Greene2018" /><ref name="CNN_Jan2019">{{cite web|work=CNN|url=https://edition.cnn.com/2019/01/14/world/climate-change-antarctica-ice-melt-twin-studies/index.html|title=Antarctica ice melt has accelerated by 280% in the last 4 decades|date=14 January 2019|access-date=January 14, 2019|quote=Melting is taking place in the most vulnerable parts of Antarctica ... parts that hold the potential for multiple metres of sea level rise in the coming century or two|archive-date=30 June 2020|archive-url=https://web.archive.org/web/20200630182349/https://edition.cnn.com/2019/01/14/world/climate-change-antarctica-ice-melt-twin-studies/index.html|url-status=live}}</ref> Altogether, Antarctica is the source of the largest uncertainty for future sea level projections.<ref name="Nature_20210505A">{{cite journal |last1=Edwards |first1=Tamsin L. |last2=Nowicki |first2=Sophie |last3=Marzeion |first3=Ben |last4=Hock |first4=Regine |last5=Goelzer |first5=Heiko |last6=Seroussi |first6=Hélène |display-authors=4 |date=5 May 2021 |title=Projected land ice contributions to twenty-first-century sea level rise |url=https://www.nature.com/articles/s41586-021-03302-y |journal=Nature |volume=593 |issue=7857 |pages=74–82 |bibcode=2021Natur.593...74E |doi=10.1038/s41586-021-03302-y |issn=0028-0836 |pmid=33953415 |hdl=1874/412157 |archive-url=https://web.archive.org/web/20210511000000/https://www.nature.com/articles/s41586-021-03302-y |archive-date=11 May 2021 |s2cid=233871029 |hdl-access=free }} Alt URL https://eprints.whiterose.ac.uk/173870/ {{Webarchive|url=https://web.archive.org/web/20230322230428/https://eprints.whiterose.ac.uk/173870/ |date=2023-03-22 }}</ref> In 2019, the ] assessed several studies attempting to estimate 2300 sea level rise caused by ice loss in Antarctica alone, arriving at projected estimates of {{Convert|0.07 - 0.37|m|ft}} for the low emission RCP2.6 scenario, and {{Convert|0.60 - 2.89|m|ft}} in the high emission RCP8.5 scenario.<ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1272}} This wide range of estimates is mainly due to the uncertainties regarding marine ice sheet and marine ice cliff instabilities.<ref name="Robel2019" /><ref name="Horton2020" /><ref name="Slangen2022" /> | |||
== Satellite sea level measurement == | |||
==== East Antarctica ==== | |||
Sea-level rise estimates from ] altimetry since 1992 (about 2.8 mm/yr) exceed those from tide gauges. It is unclear whether this represents an increase over the last decades; variability; true differences between satellites and tide gauges; or problems with satellite ].{{ref|www.grida.no.304}} | |||
{{Further|East Antarctic Ice Sheet}} | |||
The world's largest potential source of sea level rise is the ] (EAIS). It is 2.2 km thick on average and holds enough ice to raise global sea levels by 53.3 m (174 ft 10 in)<ref>{{cite journal |last1=Fretwell |first1=P. |last2=Pritchard |first2=H. D. |last3=Vaughan |first3=D. G. |last4=Bamber |first4=J. L. |last5=Barrand |first5=N. E. |last6=Bell |first6=R. |last7=Bianchi |first7=C. |last8=Bingham |first8=R. G. |last9=Blankenship |first9=D. D. |last10=Casassa |first10=G. |last11=Catania |first11=G. |last12=Callens |first12=D. |last13=Conway |first13=H. |last14=Cook |first14=A. J. |last15=Corr |first15=H. F. J. |last16=Damaske |first16=D. |last17=Damm |first17=V. |last18=Ferraccioli |first18=F. |last19=Forsberg |first19=R. |last20=Fujita |first20=S. |last21=Gim |first21=Y. |last22=Gogineni |first22=P. |last23=Griggs |first23=J. A. |last24=Hindmarsh |first24=R. C. A. |last25=Holmlund |first25=P. |last26=Holt |first26=J. W. |last27=Jacobel |first27=R. W. |last28=Jenkins |first28=A. |last29=Jokat |first29=W. |last30=Jordan |first30=T. |last31=King |first31=E. C. |last32=Kohler |first32=J. |last33=Krabill |first33=W. |last34=Riger-Kusk |first34=M. |last35=Langley |first35=K. A. |last36=Leitchenkov |first36=G. |last37=Leuschen |first37=C. |last38=Luyendyk |first38=B. P. |last39=Matsuoka |first39=K. |last40=Mouginot |first40=J. |last41=Nitsche |first41=F. O. |last42=Nogi |first42=Y. |last43=Nost |first43=O. A. |last44=Popov |first44=S. V. |last45=Rignot |first45=E. |last46=Rippin |first46=D. M. |last47=Rivera |first47=A. |last48=Roberts |first48=J. |last49=Ross |first49=N. |last50=Siegert |first50=M. J. |last51=Smith |first51=A. M. |last52=Steinhage |first52=D. |last53=Studinger |first53=M. |last54=Sun |first54=B. |last55=Tinto |first55=B. K. |last56=Welch |first56=B. C. |last57=Wilson |first57=D. |last58=Young |first58=D. A. |last59=Xiangbin |first59=C. |last60=Zirizzotti |first60=A. |title=Bedmap2: improved ice bed, surface and thickness datasets for Antarctica |journal=The Cryosphere |date=28 February 2013 |volume=7 |issue=1 |pages=375–393 |doi=10.5194/tc-7-375-2013 |bibcode=2013TCry....7..375F |doi-access=free|hdl=1808/18763 |hdl-access=free }}</ref> Its great thickness and high elevation make it more stable than the other ice sheets.<ref name="Singh2020">{{Cite journal |last1=Singh |first1=Hansi A. |last2=Polvani |first2=Lorenzo M. |date=10 January 2020 |title=Low Antarctic continental climate sensitivity due to high ice sheet orography |journal=npj Climate and Atmospheric Science |language=en |volume=3 |issue=1 |page=39 |doi=10.1038/s41612-020-00143-w |s2cid=222179485 |doi-access=free |bibcode=2020npCAS...3...39S}}</ref> As of the early 2020s, most studies show that it is still gaining mass.<ref name="King2012">{{Cite journal|last1 = King|first1 = M. A.|last2 = Bingham|first2 = R. J.|last3 = Moore|first3 = P.|last4 = Whitehouse|first4 = P. L.|last5 = Bentley|first5 = M. J.|last6 = Milne|first6 = G. A.|doi = 10.1038/nature11621|title = Lower satellite-gravimetry estimates of Antarctic sea-level contribution|journal = Nature|volume = 491|issue = 7425|pages = 586–589|year = 2012|pmid = 23086145|bibcode = 2012Natur.491..586K|s2cid = 4414976}}</ref><ref name="IMBIE2018"/><ref name="Zwally2021" /><ref name="NASA2023">{{cite web |title=Antarctic Ice Mass Loss 2002-2023 |url=https://svs.gsfc.nasa.gov/31158 |author=NASA |date=7 July 2023 |access-date=15 January 2024 |archive-date=18 January 2024 |archive-url=https://web.archive.org/web/20240118033629/https://svs.gsfc.nasa.gov/31158 |url-status=live }}</ref> Some analyses have suggested it began to lose mass in the 2000s.<ref>{{cite journal |last1=Chen |first1=J. L. |last2=Wilson |first2=C. R. |last3=Blankenship |first3=D. |last4=Tapley |first4=B. D. |year=2009 |title=Accelerated Antarctic ice loss from satellite gravity measurements |journal=Nature Geoscience |volume=2 |issue=12 |pages=859 |doi=10.1038/ngeo694 |bibcode=2009NatGe...2..859C |s2cid=130927366}}</ref><ref name="Rignot2019">{{cite journal |last1=Rignot |first1=Eric |last2=Mouginot |first2=Jérémie |last3=Scheuchl |first3=Bernd |last4=van den Broeke |first4=Michiel |last5=van Wessem |first5=Melchior J. |last6=Morlighem |first6=Mathieu |title=Four decades of Antarctic Ice Sheet mass balance from 1979–2017 |journal=Proceedings of the National Academy of Sciences |date=22 January 2019 |volume=116 |issue=4 |pages=1095–1103 |doi=10.1073/pnas.1812883116 |pmid=30642972 |pmc=6347714 |bibcode=2019PNAS..116.1095R |doi-access=free}}</ref><ref name="CNN_Jan2019"/> However they over-extrapolated some observed losses on to the poorly observed areas. A more complete observational record shows continued mass gain.<ref name="Zwally2021">{{Cite journal |last1=Zwally |first1=H. Jay |last2=Robbins |first2=John W. |last3=Luthcke |first3=Scott B. |last4=Loomis |first4=Bryant D. |last5=Rémy |first5=Frédérique |date=29 March 2021 |title=Mass balance of the Antarctic ice sheet 1992–2016: reconciling results from GRACE gravimetry with ICESat, ERS1/2 and Envisat altimetry |journal=Journal of Glaciology |language=en |volume=67 |issue=263 |pages=533–559 |doi=10.1017/jog.2021.8 |bibcode=2021JGlac..67..533Z |quote=Although their methods of interpolation or extrapolation for areas with unobserved output velocities have an insufficient description for the evaluation of associated errors, such errors in previous results (Rignot and others, 2008) caused large overestimates of the mass losses as detailed in Zwally and Giovinetto (Zwally and Giovinetto, 2011).|doi-access=free }}</ref> | |||
Since 1992 the '''NASA/CNES ]''' (''T/P'') and ''']''' satellite programs have provided measurements of sea level change. The current data are available at ''http://sealevel.colorado.edu/'' and ''http://sealevel.jpl.nasa.gov/''. The data show a mean sea level increase of 2.8±0.4 mm/yr. This includes an apparent increase to 3.7±0.2 mm/yr during the period 1999 through 2004 {{ref|membrane.com.305}}. Satellites '''ERS-1''' (] ]-] ]),{{ref|earth.esa.int.306}} '''ERS-2''' (] ]-),{{ref|www.esa.int.307}} and '''Envisat''' (] ]-) also have sea surface altimeter components but are of limited use for measuring global mean sea level due to less detailed coverage. | |||
] | |||
In spite of the net mass gain, some East Antarctica glaciers have lost ice in recent decades due to ] and declining structural support from the local ],<ref name="Greene2018">{{cite journal |last1=Greene |first1=Chad A. |last2=Young |first2=Duncan A. |last3=Gwyther |first3=David E. |last4=Galton-Fenzi |first4=Benjamin K. |last5=Blankenship |first5=Donald D. |title=Seasonal dynamics of Totten Ice Shelf controlled by sea ice buttressing |journal=The Cryosphere |date=6 September 2018 |volume=12 |issue=9 |pages=2869–2882 |doi=10.5194/tc-12-2869-2018 |bibcode=2018TCry...12.2869G |doi-access=free}}</ref> such as ],<ref name="BrancatoRignot2020">{{cite journal|last1=Brancato |first1=V. |last2=Rignot |first2=E. |last3=Milillo |first3=P. |last4=Morlighem |first4=M. |last5=Mouginot |first5=J. |last6=An |first6=L. |last7=Scheuchl |first7=B. |last8=Jeong |first8=S. |last9=Rizzoli |first9=P. |last10=Bueso Bello |first10=J.L. |last11=Prats-Iraola |first11=P. |title=Grounding line retreat of Denman Glacier, East Antarctica, measured with COSMO-SkyMed radar interferometry data |journal=Geophysical Research Letters |year=2020 |volume=47 |issue=7 |pages=e2019GL086291|issn=0094-8276 |doi=10.1029/2019GL086291 |bibcode=2020GeoRL..4786291B |doi-access=free}}</ref><ref>{{cite news|newspaper=]|url=https://www.bbc.com/news/science-environment-52007637|title=Climate change: Earth's deepest ice canyon vulnerable to melting|last=Amos|first=Jonathan|date=2020-03-23|access-date=2024-01-13|archive-date=2024-01-13|archive-url=https://web.archive.org/web/20240113200523/https://www.bbc.com/news/science-environment-52007637|url-status=live}}</ref> and ].<ref>{{cite journal |last1=Greene |first1=Chad A. |last2=Blankenship |first2=Donald D. |last3=Gwyther |first3=David E. |last4=Silvano |first4=Alessandro |last5=van Wijk |first5=Esmee |title=Wind causes Totten Ice Shelf melt and acceleration |journal=Science Advances |date=1 November 2017 |volume=3 |issue=11 |pages=e1701681 |doi=10.1126/sciadv.1701681 |pmid=29109976 |pmc=5665591 |bibcode=2017SciA....3E1681G}}</ref><ref>{{cite journal |last1=Roberts |first1=Jason |last2=Galton-Fenzi |first2=Benjamin K. |last3=Paolo |first3=Fernando S. |last4=Donnelly |first4=Claire |last5=Gwyther |first5=David E. |last6=Padman |first6=Laurie |last7=Young |first7=Duncan |last8=Warner |first8=Roland |last9=Greenbaum |first9=Jamin |last10=Fricker |first10=Helen A. |last11=Payne |first11=Antony J. |last12=Cornford |first12=Stephen |last13=Le Brocq |first13=Anne |last14=van Ommen |first14=Tas |last15=Blankenship |first15=Don |last16=Siegert |first16=Martin J. |title=Ocean forced variability of Totten Glacier mass loss |journal=Geological Society, London, Special Publications |date=2018 |volume=461 |issue=1 |pages=175–186 |doi=10.1144/sp461.6 |bibcode=2018GSLSP.461..175R |s2cid=55567382 |url=https://research-information.bristol.ac.uk/en/publications/ocean-forced-variability-of-totten-glacier-mass-loss(27694a07-b3c7-45fd-bdfb-74eb6b09c3e0).html |doi-access=free|hdl=10871/28918 |hdl-access=free }}</ref> Totten Glacier is particularly important because it stabilizes the ]. Subglacial basins like Aurora and ] are major ice reservoirs together holding as much ice as all of West Antarctica.<ref>{{cite journal |last1=Greenbaum |first1=J. S. |last2=Blankenship |first2=D. D. |last3=Young |first3=D. A. |last4=Richter |first4=T. G. |last5=Roberts |first5=J. L. |last6=Aitken |first6=A. R. A. |last7=Legresy |first7=B. |last8=Schroeder |first8=D. M. |last9=Warner |first9=R. C. |last10=van Ommen |first10=T. D. |last11=Siegert |first11=M. J. |title=Ocean access to a cavity beneath Totten Glacier in East Antarctica |journal=Nature Geoscience |date=16 March 2015 |volume=8 |issue=4 |pages=294–298 |doi=10.1038/ngeo2388 |bibcode=2015NatGe...8..294G}}</ref> They are more vulnerable than the rest of East Antarctica.<ref name="Pollard2015">{{cite journal |last1=Pollard |first1=David |last2=DeConto |first2=Robert M. |last3=Alley |first3=Richard B. |title=Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure |journal=Earth and Planetary Science Letters |date=February 2015 |volume=412 |pages=112–121 |doi=10.1016/j.epsl.2014.12.035 |bibcode=2015E&PSL.412..112P |doi-access=free}}</ref> Their collective ] probably lies at around {{convert|3|C-change|F-change}} of global warming. It may be as high as {{convert|6|C-change|F-change}} or as low as {{convert|2|C-change|F-change}}. Once this tipping point is crossed, the collapse of these subglacial basins could take place over as little as 500 or as much as 10,000 years. The median timeline is 2000 years.<ref name="ArmstrongMcKay2022" /><ref name="ArmstrongMcKayExplainer" /> Depending on how many subglacial basins are vulnerable, this causes sea level rise of between {{convert|1.4|m|ftin|abbr=on}} and {{convert|6.4|m|ftin|abbr=on}}.<ref name="Pan2021">{{Cite journal|last1=Pan |first1=Linda |last2=Powell |first2=Evelyn M. |last3=Latychev |first3=Konstantin |last4=Mitrovica |first4=Jerry X. |last5=Creveling |first5=Jessica R. |last6=Gomez |first6=Natalya |last7=Hoggard |first7=Mark J. |last8=Clark |first8=Peter U. |date=30 April 2021 |title=Rapid postglacial rebound amplifies global sea level rise following West Antarctic Ice Sheet collapse |journal=Science Advances |volume=7 |issue=18 |doi=10.1126/sciadv.abf7787 |pmid=33931453 |pmc=8087405 |bibcode=2021SciA....7.7787P}}</ref> | |||
On the other hand, the whole EAIS would not definitely collapse until global warming reaches {{convert|7.5|C-change|F-change}}, with a range between {{convert|5|C-change|F-change}} and {{convert|10|C-change|F-change}}. It would take at least 10,000 years to disappear.<ref name="ArmstrongMcKay2022" /><ref name="ArmstrongMcKayExplainer" /> Some scientists have estimated that warming would have to reach at least {{convert|6|C-change|F-change}} to melt two thirds of its volume.<ref name="Garbe2020">{{Cite journal |last1=Garbe |first1=Julius |last2=Albrecht |first2=Torsten |last3=Levermann |first3=Anders |last4=Donges |first4=Jonathan F. |last5=Winkelmann |first5=Ricarda |date=2020 |title=The hysteresis of the Antarctic Ice Sheet |url=https://www.nature.com/articles/s41586-020-2727-5 |journal=Nature |volume=585 |issue=7826 |pages=538–544 |doi=10.1038/s41586-020-2727-5 |pmid=32968257 |bibcode=2020Natur.585..538G |s2cid=221885420 |access-date=2022-10-23 |archive-date=2023-08-19 |archive-url=https://web.archive.org/web/20230819234302/https://www.nature.com/articles/s41586-020-2727-5 |url-status=live }}</ref> | |||
* TOPEX/Poseidon began their series of measurements in 1992. The POSEIDON-1 altimeter operates 10% of the time. | |||
* Jason-1, launched ], ], is presently flying the same groundtrack, leading Poseidon.{{ref|sealevel.jpl.nasa.gov.308}} | |||
* After Jason-1 calibration is complete, ''T/P'' will be moved to an orbit midway between Jason-1 groundtracks, providing increased coverage. | |||
==== West Antarctica ==== | |||
Because significant short-term variability in sea level can occur, extracting the global mean sea level information is complex. Also, the satellite data has a much shorter record than tidal gauges, which have been found to require years of operation to extract trends. | |||
{{Further|West Antarctic Ice Sheet}} | |||
] | |||
There is a range of distances involved. | |||
East Antarctica contains the largest potential source of sea level rise. However the ] (WAIS) is substantially more vulnerable. Temperatures on West Antarctica have increased significantly, unlike East Antarctica and the ]. The trend is between {{convert|0.08|C-change|F-change}} and {{convert|0.96|C-change|F-change}} per decade between 1976 and 2012.<ref>{{cite journal |last1=Ludescher |first1=Josef |last2=Bunde |first2=Armin |last3=Franzke |first3=Christian L. E. |last4=Schellnhuber |first4=Hans Joachim |title=Long-term persistence enhances uncertainty about anthropogenic warming of Antarctica |journal=Climate Dynamics |date=16 April 2015 |volume=46 |issue=1–2 |pages=263–271 |doi=10.1007/s00382-015-2582-5 |bibcode=2016ClDy...46..263L |s2cid=131723421}}</ref> Satellite observations recorded a substantial increase in WAIS melting from 1992 to 2017. This resulted in {{Convert|7.6 ± 3.9|mm|in|frac=64|abbr=on}} of Antarctica sea level rise. Outflow glaciers in the ] played a disproportionate role.<ref name="RignotBamber2008">{{cite journal |last1=Rignot |first1=Eric |last2=Bamber |first2=Jonathan L. |last3=van den Broeke |first3=Michiel R. |last4=Davis |first4=Curt |last5=Li |first5=Yonghong |last6=van de Berg |first6=Willem Jan |last7=van Meijgaard |first7=Erik |title=Recent Antarctic ice mass loss from radar interferometry and regional climate modelling |journal=Nature Geoscience |date=13 January 2008 |volume=1 |issue=2 |pages=106–110 |doi=10.1038/ngeo102 |bibcode=2008NatGe...1..106R |s2cid=784105 |url=http://www.escholarship.org/uc/item/26f4j9vv |access-date=11 December 2019 |archive-date=2 March 2020 |archive-url=https://web.archive.org/web/20200302093403/https://escholarship.org/uc/item/26f4j9vv |url-status=live }}</ref> | |||
* 140 to 320 mm: Increased height of sea level within 1997-] ] Pacific region.{{ref|www.earth.nasa.gov.309}} | |||
* 140 mm: Range of typical regional sea level variations (±70 mm).{{ref|ibis.grdl.noaa.gov.310}} | |||
* 100 mm: Accuracy of ERS-1 radar altimeter.{{ref|earth.esa.int.311}} | |||
* 43 mm: Accuracy of ocean surface height calculations with ''T/P''.{{ref|sealevel.jpl.nasa.gov.312}} | |||
* 30 to 40 mm: Accuracy of TOPEX and POSEIDON-1 radar altimeters, which measure distance to ocean surface. | |||
* 20 to 30 mm: Accuracy of determination of ''T/P'' satellite orbital height (laser ranging, doppler shifts, GPS). | |||
* 20 mm: Accuracy of Jason-1 POSEIDON-2 radar altimeter.{{ref|www.jason.oceanobs.com.313}} | |||
* 7-14 mm: Global mean sea level surge during 1997-] ] period.{{ref|sealevel.jpl.nasa.gov.314}} | |||
* Several mm: Precision of global mean sea level measurement after averaging 10-day coverage.{{ref|sealevel.jpl.nasa.gov.315}} | |||
* 10 mm: Stability of ''T/P'' orbit heights over 4 years.{{ref|ams.allenpress.com.316}} | |||
* 2.8 ±0.4 mm: Average annual global sea level rise since 1992 according to ''T/P''. | |||
* 2 mm: ''T/P'' drift of unknown source.{{ref|ams.allenpress.com.317}} | |||
] | |||
There apparently is a problem with the ERS-2 altimeter. | |||
Mean sea level changes were compared between satellites for 60°N and 60°S from May ] to June ]:{{ref|earth.esa.int.318}} | |||
* -4.7 ±1.5 mm/yr for ERS-1 | |||
* -5.6 ±1.3 mm/yr for TOPEX | |||
* +9.0 ±2.1 mm/yr for ERS-2 | |||
The ''median'' estimated increase in sea level rise from Antarctica by 2100 is ~{{convert|11|cm|in|round=5|abbr=on}}. There is no difference between scenarios, because the increased warming would ] and increase ] accumulation over the EAIS at about the same rate as it would increase ice loss from WAIS.<ref name="IPCC AR6 WG1 Ch.9" /> However, most of the ] underlying the WAIS lies well below sea level, and it has to be buttressed by the ] and ] glaciers. If these glaciers were to collapse, the entire ice sheet would as well.<ref name="Pollard2015"/> Their disappearance would take at least several centuries, but is considered almost inevitable, as their bedrock ] deepens inland and becomes more vulnerable to meltwater, in what is known as marine ice sheet instability.<ref name="Robel2019">{{cite journal |last1=Robel |first1=Alexander A. |last2=Seroussi |first2=Hélène |last3=Roe |first3=Gerard H. |title=Marine ice sheet instability amplifies and skews uncertainty in projections of future sea-level rise |journal=Proceedings of the National Academy of Sciences |date=23 July 2019 |volume=116 |issue=30 |pages=14887–14892 |doi=10.1073/pnas.1904822116 |pmid=31285345 |pmc=6660720 |bibcode=2019PNAS..11614887R |doi-access=free}}</ref><ref name="Pettit2021">{{Cite web|last1=Voosen|first1=Paul|date=13 December 2021|title=Ice shelf holding back keystone Antarctic glacier within years of failure|url=https://www.science.org/content/article/ice-shelf-holding-back-keystone-antarctic-glacier-within-years-failure|access-date=2022-10-22|website=]|language=en|quote=Because Thwaites sits below sea level on ground that dips away from the coast, the warm water is likely to melt its way inland, beneath the glacier itself, freeing its underbelly from bedrock. A collapse of the entire glacier, which some researchers think is only centuries away, would raise global sea level by 65 centimeters.|archive-date=2023-04-18|archive-url=https://web.archive.org/web/20230418221429/https://www.science.org/content/article/ice-shelf-holding-back-keystone-antarctic-glacier-within-years-failure|url-status=live}}</ref><ref name=BBC1 >{{cite news |last=Amos |first=Jonathan |date=13 December 2021 |title=Thwaites: Antarctic glacier heading for dramatic change |url=https://www.bbc.com/news/science-environment-59644494 |work=] |location=London |access-date=December 14, 2021 |archive-date=22 January 2022 |archive-url=https://web.archive.org/web/20220122115541/https://www.bbc.com/news/science-environment-59644494 |url-status=live }}</ref> | |||
Ongoing altimeter comparisons are available at: ''http://www7300.nrlssc.navy.mil/altimetry/intercomp.html''<br> | |||
The various readings there are of current sea level variations, not global sea level, so the comparison is only in differences between the values. That data is of variations in centimeters; further processing is done to reach the millimeter-level resolution needed for mean sea level studies. | |||
The contribution of these glaciers to global sea levels has already accelerated since the year 2000. The Thwaites Glacier now accounts for 4% of global sea level rise.<ref name="Pettit2021" /><ref>{{cite web|url=https://www.theatlantic.com/science/archive/2018/06/after-decades-of-ice-loss-antarctica-is-now-hemorrhaging-mass/562748/|work=The Atlantic|year=2018|title=After Decades of Losing Ice, Antarctica Is Now Hemorrhaging It|access-date=2018-08-29|archive-date=2020-03-19|archive-url=https://web.archive.org/web/20200319000046/https://www.theatlantic.com/science/archive/2018/06/after-decades-of-ice-loss-antarctica-is-now-hemorrhaging-mass/562748/|url-status=live}}</ref><ref>{{cite web|url=http://www.antarcticglaciers.org/glaciers-and-climate/ice-ocean-interactions/marine-ice-sheets/|work=AntarcticGlaciers.org|year=2014|title=Marine ice sheet instability|access-date=2018-08-29|archive-date=2020-05-03|archive-url=https://web.archive.org/web/20200503235803/http://www.antarcticglaciers.org/glaciers-and-climate/ice-ocean-interactions/marine-ice-sheets/|url-status=live}}</ref> It could start to lose even more ice if the ] fails and would no longer stabilize it, which could potentially occur in mid-2020s.<ref name=Kaplan1>{{cite news |last=Kaplan |first=Sarah |date=December 13, 2021 |title=Crucial Antarctic ice shelf could fail within five years, scientists say |url=https://www.washingtonpost.com/climate-environment/2021/12/13/thwaites-glacier-melt-antarctica/ |newspaper=] |location=Washington DC |access-date=December 14, 2021 |archive-date=August 19, 2023 |archive-url=https://web.archive.org/web/20230819193033/https://www.washingtonpost.com/climate-environment/2021/12/13/thwaites-glacier-melt-antarctica/ |url-status=live }}</ref> A combination of ice sheet instability with other important but hard-to-model processes like hydrofracturing (meltwater collects atop the ice sheet, pools into fractures and forces them open)<ref name="pmid30013142">{{cite journal |last1=Pattyn |first1=Frank |author-link=Frank Pattyn |date=16 July 2018 |title=The paradigm shift in Antarctic ice sheet modelling |journal=Nature Communications |volume=9 |issue=1 |page=2728 |bibcode=2018NatCo...9.2728P |doi=10.1038/s41467-018-05003-z |pmc=6048022 |pmid=30013142}}</ref> or smaller-scale changes in ocean circulation<ref>{{Cite journal |last1=Golledge |first1=Nicholas R. |last2=Keller |first2=Elizabeth D. |last3=Gomez |first3=Natalya |last4=Naughten |first4=Kaitlin A. |last5=Bernales |first5=Jorge |last6=Trusel |first6=Luke D. |last7=Edwards |first7=Tamsin L. |date=2019 |title=Global environmental consequences of twenty-first-century ice-sheet melt |journal=Nature |language=en |volume=566 |issue=7742 |pages=65–72 |doi=10.1038/s41586-019-0889-9 |pmid=30728520 |bibcode=2019Natur.566...65G |s2cid=59606358 |issn=1476-4687}}</ref><ref>{{Cite journal |last1=Moorman |first1=Ruth |last2=Morrison |first2=Adele K. |last3=Hogg |first3=Andrew McC |date=2020-08-01 |title=Thermal Responses to Antarctic Ice Shelf Melt in an Eddy-Rich Global Ocean–Sea Ice Model |journal=Journal of Climate |language=EN |volume=33 |issue=15 |pages=6599–6620 |doi=10.1175/JCLI-D-19-0846.1 |bibcode=2020JCli...33.6599M |s2cid=219487981 |issn=0894-8755}}</ref><ref name="Naughten2023">{{cite journal |last1=A. Naughten |first1=Kaitlin |last2=R. Holland |first2=Paul |last3=De Rydt |first3=Jan |date=23 October 2023 |title=Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first century |journal=Nature Climate Change |volume=13 |issue=11 |pages=1222–1228 |bibcode=2023NatCC..13.1222N |doi=10.1038/s41558-023-01818-x |s2cid=264476246 |doi-access=free}}</ref> could cause the WAIS to contribute up to {{convert|41|cm|in|0|abbr=on}} by 2100 under the low-emission scenario and up to {{convert|57|cm|in|0|abbr=on}} under the highest-emission one.<ref name="IPCC AR6 WG1 Ch.9" /> Ice cliff instability would cause a contribution of {{cvt|1|m|ft|frac=2}} or more if it were applicable.<ref name="DeConto2016" /><ref name="Kopp2023" /> | |||
Comparisons of ''T/P'' with Pacific island tide gauge data show that the monthly mean deviations are accurate at the level of 20 mm.{{ref|ibis.grdl.noaa.gov.319}} | |||
The melting of all the ] in West Antarctica would increase the total sea level rise to {{convert|4.3|m|ftin|abbr=on}}.<ref name="BEDMAP2-2013">{{cite journal |last1=Fretwell |first1=P. |display-authors=et al |title=Bedmap2: improved ice bed, surface and thickness datasets for Antarctica |journal=The Cryosphere |volume=7 |issue=1 |page=390 |date=28 February 2013 |url=http://www.the-cryosphere.net/7/375/2013/tc-7-375-2013.pdf |access-date=6 January 2014 |doi=10.5194/tc-7-375-2013 |bibcode=2013TCry....7..375F |s2cid=13129041 |doi-access=free |archive-date=16 February 2020 |archive-url=https://web.archive.org/web/20200216072841/https://www.the-cryosphere.net/7/375/2013/tc-7-375-2013.pdf |url-status=live}}</ref> However, mountain ]s not in contact with water are less vulnerable than the majority of the ice sheet, which is located below the sea level.<ref name="Hein2016">{{Cite journal |last1=Hein |first1=Andrew S. |last2=Woodward |first2=John |last3=Marrero |first3=Shasta M. |last4=Dunning |first4=Stuart A. |last5=Steig |first5=Eric J. |last6=Freeman |first6=Stewart P. H. T. |last7=Stuart |first7=Finlay M. |last8=Winter |first8=Kate |last9=Westoby |first9=Matthew J. |last10=Sugden |first10=David E. |date=3 February 2016 |title=Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years |journal=Nature Communications |volume=7 |page=10325 |doi=10.1038/ncomms10325 |pmid=26838462 |pmc=4742792 |bibcode=2016NatCo...710325H}}</ref> Its collapse would cause ~{{convert|3.3|m|ftin|abbr=on}} of sea level rise.<ref name="Bamber2009">{{cite journal |last1=Bamber |first1=J.L. |last2=Riva |first2=R.E.M. |last3=Vermeersen |first3=B.L.A. |last4=LeBrocq |first4=A.M. |title=Reassessment of the Potential Sea-Level Rise from a Collapse of the West Antarctic Ice Sheet |journal=Science |date=14 May 2009 |volume=324 |issue=5929 |pages=901–903 |doi=10.1126/science.1169335 |pmid=19443778 |bibcode=2009Sci...324..901B |s2cid=11083712}}</ref> This disappearance would take an estimated 2000 years. The absolute minimum for the loss of West Antarctica ice is 500 years, and the potential maximum is 13,000 years.<ref name="ArmstrongMcKay2022">{{Cite journal |last1=Armstrong McKay |first1=David |last2=Abrams |first2=Jesse |last3=Winkelmann |first3=Ricarda |last4=Sakschewski |first4=Boris |last5=Loriani |first5=Sina |last6=Fetzer |first6=Ingo |last7=Cornell |first7=Sarah |last8=Rockström |first8=Johan |last9=Staal |first9=Arie |last10=Lenton |first10=Timothy |date=9 September 2022 |title=Exceeding 1.5°C global warming could trigger multiple climate tipping points |url=https://www.science.org/doi/10.1126/science.abn7950 |journal=Science |language=en |volume=377 |issue=6611 |pages=eabn7950 |doi=10.1126/science.abn7950 |pmid=36074831 |hdl=10871/131584 |s2cid=252161375 |issn=0036-8075 |access-date=23 October 2022 |archive-date=14 November 2022 |archive-url=https://web.archive.org/web/20221114143835/https://www.science.org/doi/10.1126/science.abn7950 |url-status=live |hdl-access=free }}</ref><ref name="ArmstrongMcKayExplainer">{{Cite web |last=Armstrong McKay |first=David |date=9 September 2022 |title=Exceeding 1.5°C global warming could trigger multiple climate tipping points – paper explainer |url=https://climatetippingpoints.info/2022/09/09/climate-tipping-points-reassessment-explainer/ |access-date=2 October 2022 |website=climatetippingpoints.info |language=en |archive-date=18 July 2023 |archive-url=https://web.archive.org/web/20230718085705/https://climatetippingpoints.info/2022/09/09/climate-tipping-points-reassessment-explainer/ |url-status=live }}</ref> | |||
Also, it should be noted that since satellite results are partially calibrated against tide gauge readings, they are not an entirely independent source. {{ref|sealevel.colorado.edu.320}} | |||
Once ice loss from the West Antarctica is triggered, the only way to restore it to near-present values is by lowering the global temperature to {{convert|1|C-change|F-change}} ''below'' the preindustrial level. This would be {{convert|2|C-change|F-change}} below the temperature of 2020.<ref name="Garbe2020" /> Other researchers suggested that a ] intervention to stabilize the ice sheet's glaciers may delay its loss by centuries and give more time to adapt. However this is an uncertain proposal, and would end up as one of the most expensive projects ever attempted.<ref name="Wolovick2023a">{{Cite journal |last1=Wolovick |first1=Michael |last2=Moore |first2=John |last3=Keefer |first3=Bowie |date=27 March 2023 |title=Feasibility of ice sheet conservation using seabed anchored curtains |url=https://academic.oup.com/pnasnexus/article/2/4/pgad103/7087219 |journal=PNAS Nexus |volume=2 |issue=3 |pages=pgad053 |language=en |doi=10.1093/pnasnexus/pgad053 |pmid=37007716 |pmc=10062297 |access-date=27 October 2023 |archive-date=6 January 2024 |archive-url=https://web.archive.org/web/20240106123807/https://academic.oup.com/pnasnexus/article/2/4/pgad103/7087219 |url-status=live }}</ref><ref name="Wolovick2023b">{{Cite journal |last1=Wolovick |first1=Michael |last2=Moore |first2=John |last3=Keefer |first3=Bowie |date=27 March 2023 |title=The potential for stabilizing Amundsen Sea glaciers via underwater curtains |url=https://academic.oup.com/pnasnexus/article/2/4/pgad103/7087219 |journal=PNAS Nexus |volume=2 |issue=4 |pages=pgad103 |language=en |doi=10.1093/pnasnexus/pgad103 |pmid=37091546 |pmc=10118300 |access-date=27 October 2023 |archive-date=6 January 2024 |archive-url=https://web.archive.org/web/20240106123807/https://academic.oup.com/pnasnexus/article/2/4/pgad103/7087219 |url-status=live }}</ref> | |||
The strong 1997-] ] event "has imprinted a strong signature on the sea surface height field in the mid-latitude eastern Pacific. This signal will be tracked over the next decade as the eastern boundary manifestation of this El Niño event propagates westward toward the Kuroshio Extension."{{ref|sealevel.jpl.nasa.gov.321}} | |||
] Text and images are available under a {{Webarchive|url=https://web.archive.org/web/20171016050101/https://creativecommons.org/licenses/by/4.0/ |date=2017-10-16 }}.</ref>]] | |||
Other satellites: | |||
* '''Geosat Follow-On''' is a U.S. Navy altimeter mission that was launched on ], ]. On ], ], the Navy accepted the satellite as operational. During its mission life, the satellite will be retained in the GEOSAT Exact Repeat Mission (ERM) orbit (800 km altitude, 108 deg inclination, 0.001 eccentricity, and, 100 min period). This 17-day Exact Repeat Orbit (ERO) retraces the ERM ground track to +/-1 km. As with the original GEOSAT ERM, the data will be available for ocean science through NOAA/NOS and NOAA/NESDIS. Radar Altimeter - single frequency (13.5 GHz) with 35 mm height precision. Note that the GPS receiver is not functional. | |||
** Geosat Follow-On @ NOAA/LSA{{ref|ibis.grdl.noaa.gov.322}} | |||
** NAVY GEOSAT FOLLOW-ON (GFO) ALTIMETRY MISSION{{ref|gfo.bmpcoe.org.323}} | |||
** NASA WFF Geosat Follow-On{{ref|gfo.wff.nasa.gov.324}} | |||
Other sea level analysis: | |||
* Sea Level Analysis from ERS Altimetry{{ref|nng.esoc.esa.de.325}} | |||
* Ssalto/Duacs multimission altimeter products{{ref|www.jason.oceanobs.com.326}}: Combined current data from Topex/Poseidon, Geosat Follow On, Jason-1 and Envisat. | |||
=== Ice sheet loss in Greenland === | |||
== References == | |||
Most ice on Greenland is in the ] which is {{Convert|3|km|ft|abbr=on|sigfig=1}} at its thickest. The rest of Greenland ice forms isolated glaciers and ice caps. The average annual ice loss in Greenland more than doubled in the early 21st century compared to the 20th century.<ref>{{cite journal |last1=Kjeldsen |first1=Kristian K. |last2=Korsgaard |first2=Niels J. |last3=Bjørk |first3=Anders A. |last4=Khan |first4=Shfaqat A. |last5=Box |first5=Jason E. |last6=Funder |first6=Svend |last7=Larsen |first7=Nicolaj K. |last8=Bamber |first8=Jonathan L. |last9=Colgan |first9=William |last10=van den Broeke |first10=Michiel |last11=Siggaard-Andersen |first11=Marie-Louise |last12=Nuth |first12=Christopher |last13=Schomacker |first13=Anders |last14=Andresen |first14=Camilla S. |last15=Willerslev |first15=Eske |last16=Kjær |first16=Kurt H. |title=Spatial and temporal distribution of mass loss from the Greenland Ice Sheet since AD 1900 |journal=Nature |date=16 December 2015 |volume=528 |issue=7582 |pages=396–400 |doi=10.1038/nature16183 |pmid=26672555 |bibcode=2015Natur.528..396K |hdl=10852/50174 |s2cid=4468824 |url=https://research-information.bris.ac.uk/en/publications/spatial-and-temporal-distribution-of-mass-loss-from-the-greenland-ice-sheet-since-ad-1900(29ed76ed-b8f7-4b99-bf59-a275b0a22ce7).html|hdl-access=free }}</ref> Its contribution to sea level rise correspondingly increased from 0.07 mm per year between 1992 and 1997 to 0.68 mm per year between 2012 and 2017. Total ice loss from the Greenland ice sheet between 1992 and 2018 amounted to 3,902 gigatons (Gt) of ice. This is equivalent to a SLR contribution of 10.8 mm.<ref>{{Cite journal|last1=Shepherd|first1=Andrew|last2=Ivins|first2=Erik|last3=Rignot|first3=Eric|last4=Smith|first4=Ben|last5=van den Broeke|first5=Michiel|last6=Velicogna|first6=Isabella|author-link6=Isabella Velicogna|last7=Whitehouse|first7=Pippa|last8=Briggs|first8=Kate|last9=Joughin|first9=Ian|last10=Krinner|first10=Gerhard|last11=Nowicki|first11=Sophie|date=2020-03-12|title=Mass balance of the Greenland Ice Sheet from 1992 to 2018|journal=Nature|language=en|volume=579|issue=7798|pages=233–239|doi=10.1038/s41586-019-1855-2|pmid=31822019|hdl=2268/242139|s2cid=219146922|issn=1476-4687|url=https://orbi.uliege.be/handle/2268/242139|access-date=2020-05-11|archive-date=2022-10-23|archive-url=https://web.archive.org/web/20221023151210/https://orbi.uliege.be/handle/2268/242139|url-status=live|hdl-access=free}}</ref> The contribution for the 2012–2016 period was equivalent to 37% of sea level rise from ''land ice'' sources (excluding thermal expansion).<ref name="Bamber2018">{{cite journal |last1=Bamber |first1=Jonathan L |last2=Westaway |first2=Richard M |last3=Marzeion |first3=Ben |last4=Wouters |first4=Bert |title=The land ice contribution to sea level during the satellite era |journal=Environmental Research Letters |date=1 June 2018 |volume=13 |issue=6 |page=063008 |doi=10.1088/1748-9326/aac2f0 |bibcode=2018ERL....13f3008B |doi-access=free|hdl=1983/58218615-dedd-43a8-a8ea-79fb83130613 |hdl-access=free }}</ref> This observed rate of ice sheet melting is at the higher end of predictions from past ] assessment reports.<ref>{{Cite web|url=https://news.uci.edu/2019/12/19/greenland-ice-loss-is-at-worse-case-scenario-levels-study-finds/|title=Greenland ice loss is at 'worse-case scenario' levels, study finds|date=2019-12-19|website=UCI News|language=en-US|access-date=2019-12-28|archive-date=2020-04-03|archive-url=https://web.archive.org/web/20200403190232/https://news.uci.edu/2019/12/19/greenland-ice-loss-is-at-worse-case-scenario-levels-study-finds/|url-status=live}}</ref><ref name="Slater-2020"/> | |||
* {{Journal reference | Author=Cazenave, A.; Nerem, R. S. | Title=Present-day sea level change: Observations and causes | Journal=Rev. Geophys | Volume=42 | Year=2004 | Pages=RG3001}} {{doi|10.1029/2003RG000139}} | |||
] | |||
* {{Book reference | Author=Emery, K.O., and D. G. Aubrey | Title=Sea levels, land levels, and tide gauges | Publisher=New York: Springer-Verlag | Year=1991 | ID=ISBN 0387974490}} | |||
In 2021, ] estimated that by 2100, the melting of Greenland ice sheet would most likely add around {{cvt|6|cm|in|frac=2}} to sea levels under the low-emission scenario, and {{cvt|13|cm|in|frac=2}} under the high-emission scenario. The first scenario, ], largely fulfils the ] goals, while the other, SSP5-8.5, has the emissions accelerate throughout the century. The uncertainty about ] can affect both pathways. In the best-case scenario, ice sheet under SSP1-2.6 gains enough mass by 2100 through ] feedbacks to reduce the sea levels by {{cvt|2|cm|in|frac=2}}. In the worst case, it adds {{cvt|15|cm|in|frac=2}}. For SSP5-8.5, the best-case scenario is adding {{cvt|5|cm|in|frac=2}} to sea levels, and the worst-case is adding {{cvt|23|cm|in|frac=2}}.<ref name="IPCC AR6 WG1 Ch.9" />{{Rp|page=1260}} | |||
* {{Journal reference | Author=Mörner, Nils-Axel | Title=Estimating future sea level changes from past records | Journal=Global and Planetary Change | Volume=40 | Issue=1-2 | Year=2004 | Pages=49-54}} {{doi|10.1016/S0921-8181(03)00097-3}} | |||
* {{Journal reference | Author=Mörner, Nils-Axel; Tooley, Michael; Possnert, Göran | Title=New perspectives for the future of the Maldives | Journal=Global and Planetary Change | Volume=40 | Issue=1-2 | Year=2004 | Pages=177-182}} {{doi|10.1016/S0921-8181(03)00108-5}} | |||
* {{Web reference | title=Sea Level Variations of the United States 1854-1999 | work=NOAA Technical Report NOS CO-OPS 36 | URL=http://co-ops.nos.noaa.gov/publications/techrpt36doc.pdf | date=] | year=2005}} | |||
* {{Journal reference | Author=Clark, P. U., Mitrovica, J. X., Milne, G. A. & Tamisiea | Title=Sea-Level Fingerprinting as a Direct Test for the Source of Global Meltwater Pulse 1A | Journal=Science | Volume=295 | Year=2002 | Pages=2438-2441}} | |||
* {{Journal reference | Author=Eelco J. Rohling, Robert Marsh, Neil C. Wells, Mark Siddall and Neil R. Edwards | Title=Similar meltwater contributions to glacial sea level changes from Antarctic and northern ice sheets | Journal=Nature | Volume=430 | Issue=] | Year=2004 | Pages=1016-1021}} {{doi|10.1038/nature02859}} | |||
* {{Journal reference | Author=Walter Munk | Title=Twentieth century sea level: An enigma | Journal=Geophysics | Volume=99 | Issue=10 | Year=2002 | Pages=6550-6555}} | |||
* {{Journal reference | Author=Laury Miller and Bruce C. Douglas | Title=Mass and volume contributions to twentieth-century global sea level rise | Journal=Nature | Volume=428 | Year=2004 | Pages=406-409}} {{doi|10.1038/nature02309}} | |||
* {{Journal reference | Author=Bruce C. Douglas and W. Richard Peltier | Title=The Puzzle of Global Sea-Level Rise | Journal=Physics Today | Volume=55 | Issue=3 | Year=2002 | Pages=35-41}} {{Web reference | title=The Puzzle of Global Sea-Level Rise | work=Physics Today | URL=http://www.aip.org/pt/vol-55/iss-3/p35.html | date=] | year=2005}} | |||
* {{Journal reference|Author=B. C. Douglas|Journal=J. Geophys. Res.|Volume=7|Issue=c8|Pages=12699|Year=1992|Title=Global sea level acceleration}} {{doi|10.1029/92JC01133}} | |||
* Warrick, R. A., C. L. Provost, M. F. Meier, J. Oerlemans, and P. L. Woodworth. 1996. Changes in sea level, in Climate Change 1995: The Science of Climate Change. pp. 359-405. | |||
* {{Journal reference|Author=R. Kwok, J. C. Comiso|Journal=Journal of Climate|Volume=15|Issue=5|Pages=487-501|Year=2002|Title=Southern Ocean Climate and Sea Ice Anomalies Associated with the Southern Oscillation}} {{doi|<nowiki>10.1175/1520-0442(2002)015<0487:SOCASI>2.0.CO;2</nowiki>}} | |||
Greenland's peripheral glaciers and ice caps crossed an irreversible tipping point around 1997. Sea level rise from their loss is now unstoppable.<ref>{{cite journal |last1=Noël |first1=B. |last2=van de Berg |first2=W. J |last3=Lhermitte |first3=S. |last4=Wouters |first4=B. |last5=Machguth |first5=H. |last6=Howat |first6=I. |last7=Citterio |first7=M. |last8=Moholdt |first8=G. |last9=Lenaerts |first9=J. T. M. |last10=van den Broeke |first10=M. R. |title=A tipping point in refreezing accelerates mass loss of Greenland's glaciers and ice caps |journal=Nature Communications |date=31 March 2017 |volume=8 |issue=1 |page=14730 |doi=10.1038/ncomms14730 |pmid=28361871 |pmc=5380968 |bibcode=2017NatCo...814730N}}</ref><ref>{{cite news|title=Warming Greenland ice sheet passes point of no return|url=https://news.osu.edu/warming-greenland-ice-sheet-passes-point-of-no-return/|date=13 August 2020|access-date=15 August 2020|work=Ohio State University|archive-date=5 September 2023|archive-url=https://web.archive.org/web/20230905013943/https://news.osu.edu/warming-greenland-ice-sheet-passes-point-of-no-return/|url-status=live}}</ref><ref>{{cite journal|last1=King|first1=Michalea D.|last2=Howat|first2=Ian M.|last3=Candela|first3=Salvatore G.|last4=Noh|first4=Myoung J.|last5=Jeong|first5=Seongsu|last6=Noël|first6=Brice P. Y.|last7=van den Broeke|first7=Michiel R.|last8=Wouters|first8=Bert|last9=Negrete|first9=Adelaide|date=13 August 2020|title=Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat|journal=Communications Earth & Environment|language=en|volume=1|issue=1|pages=1–7|doi=10.1038/s43247-020-0001-2|bibcode=2020ComEE...1....1K |issn=2662-4435|doi-access=free}} ] Text and images are available under a ].</ref> However the temperature changes in future, the warming of 2000–2019 had already damaged the ice sheet enough for it to eventually lose ~3.3% of its volume. This is leading to {{cvt|27|cm|in|frac=2}} of future sea level rise.<ref>{{cite journal |last1=Box |first1=Jason E. |last2=Hubbard |first2=Alun |last3=Bahr |first3=David B. |last4=Colgan |first4=William T. |last5=Fettweis |first5=Xavier |last6=Mankoff |first6=Kenneth D. |last7=Wehrlé |first7=Adrien |last8=Noël |first8=Brice |last9=van den Broeke |first9=Michiel R. |last10=Wouters |first10=Bert |last11=Bjørk |first11=Anders A. |last12=Fausto |first12=Robert S. |title=Greenland ice sheet climate disequilibrium and committed sea-level rise |journal=Nature Climate Change |date=29 August 2022 |volume=12 |issue=9 |pages=808–813 |doi=10.1038/s41558-022-01441-2 |bibcode=2022NatCC..12..808B |s2cid=251912711 |doi-access=free |hdl=10037/26654 |hdl-access=free }}</ref> At a certain level of global warming, the Greenland ice sheet will almost completely melt. Ice cores show this happened at least once over the last million years, during which the temperatures have at most been {{convert|2.5|C-change|F-change}} warmer than the preindustrial average.<ref>{{Cite journal|last1=Irvalı|first1=Nil|last2=Galaasen|first2=Eirik V.|last3=Ninnemann|first3=Ulysses S.|last4=Rosenthal|first4=Yair|last5=Born|first5=Andreas|last6=Kleiven|first6=Helga (Kikki) F.|date=18 December 2019 |title=A low climate threshold for south Greenland Ice Sheet demise during the Late Pleistocene|journal=Proceedings of the National Academy of Sciences|volume=117|issue=1|pages=190–195|language=en|doi=10.1073/pnas.1911902116|issn=0027-8424|pmid=31871153|pmc=6955352|doi-access=free}}</ref><ref name="Christ2021">{{cite journal |last1=Christ |first1=Andrew J. |last2=Bierman |first2=Paul R. |last3=Schaefer |first3=Joerg M.|last4=Dahl-Jensen |first4=Dorthe |last5=Steffensen |first5=Jørgen P. |last6=Corbett |first6=Lee B. |last7=Peteet |first7=Dorothy M. |last8=Thomas |first8=Elizabeth K. |last9=Steig |first9=Eric J. |last10=Rittenour |first10=Tammy M. |last11=Tison |first11=Jean-Louis |last12=Blard |first12=Pierre-Henri |last13=Perdrial |first13=Nicolas |last14=Dethier |first14=David P. |last15=Lini |first15=Andrea |last16=Hidy |first16=Alan J. |last17=Caffee |first17=Marc W. |last18=Southon |first18=John |title=A multimillion-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century |journal=Proceedings of the National Academy of Sciences of the United States|date=30 March 2021 |volume=118 |issue=13 |pages=e2021442118 |doi=10.1073/pnas.2021442118 |pmid=33723012 |pmc=8020747 |bibcode=2021PNAS..11821442C |doi-access=free}}</ref> | |||
== Notes == | |||
# {{note|www.grida.no.275}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/425.htm | date=2005-12-16 }} | |||
2012 modelling suggested that the tipping point of the ice sheet was between {{convert|0.8|C-change|F-change}} and {{convert|3.2|C-change|F-change}}.<ref>{{cite journal |last1=Robinson |first1=Alexander |last2=Calov |first2=Reinhard |last3=Ganopolski |first3=Andrey |title=Multistability and critical thresholds of the Greenland ice sheet |journal=Nature Climate Change |date=11 March 2012 |volume=2 |issue=6 |pages=429–432 |doi=10.1038/nclimate1449 |bibcode=2012NatCC...2..429R}}</ref> 2023 modelling has narrowed the tipping threshold to a {{convert|1.7|C-change|F-change}}-{{convert|2.3|C-change|F-change}} range, which is consistent with the empirical {{convert|2.5|C-change|F-change}} upper limit from ice cores. If temperatures reach or exceed that level, reducing the global temperature to {{convert|1.5|C-change|F-change}} above pre-industrial levels or lower would prevent the loss of the entire ice sheet. One way to do this in theory would be large-scale ], but there would still be cause of greater ice losses and sea level rise from Greenland than if the threshold was not breached in the first place.<ref name="Bochow2023">{{cite journal |last1=Bochow |first1=Nils |last2=Poltronieri |first2=Anna |last3=Robinson |first3=Alexander |last4=Montoya |first4=Marisa |last5=Rypdal |first5=Martin |last6=Boers |first6=Niklas |date=18 October 2023 |title=Overshooting the critical threshold for the Greenland ice sheet |journal=Nature |volume=622 |issue=7983 |pages=528–536 |bibcode=2023Natur.622..528B |doi=10.1038/s41586-023-06503-9 |pmc=10584691 |pmid=37853149}}</ref> If the tipping point instead is durably but mildly crossed, the ice sheet would take between 10,000 and 15,000 years to disintegrate entirel, with a most likely estimate of 10,000 years.<ref name="ArmstrongMcKay2022" /><ref name="ArmstrongMcKayExplainer" /> If climate change continues along its worst trajectory and temperatures continue to rise quickly over multiple centuries, it would only take 1,000 years.<ref name="Aschwanden2019">{{Cite journal |last1=Aschwanden |first1=Andy |last2=Fahnestock |first2=Mark A. |last3=Truffer |first3=Martin |last4=Brinkerhoff |first4=Douglas J. |last5=Hock |first5=Regine |last6=Khroulev |first6=Constantine |last7=Mottram |first7=Ruth |last8=Khan |first8=S. Abbas |date=19 June 2019 |title=Contribution of the Greenland Ice Sheet to sea level over the next millennium |journal=Science Advances |volume=5 |issue=6 |pages=218–222 |language=EN |doi=10.1126/sciadv.aav9396 |pmid=31223652 |pmc=6584365 |bibcode=2019SciA....5.9396A}}</ref> | |||
# {{note|www.grida.no.276}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/426.htm | date=2005-12-16 }} | |||
# {{note|www.grida.no.277}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/412.htm#tab113 | date=2005-12-16 }} | |||
=== Mountain glacier loss === | |||
# {{note|www.grida.no.278}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/428.htm | date=2005-12-16 }} | |||
] | |||
# {{note|refbot.279}} {{Web reference | title=University of Colorado Global mean sea level | url=http://sealevel.colorado.edu | date=2005-12-16 }} | |||
# {{note|membrane.com.280}} {{Web reference | title=Satellite Measurements of Sea Level Rise | url=http://membrane.com/sidd/sealevel.html | date=2005-12-16 }} | |||
There are roughly 200,000 glaciers on Earth, which are spread out across all continents.<ref name="Huss-2015">{{cite journal |last1=Huss |first1=Matthias |last2=Hock |first2=Regine |title=A new model for global glacier change and sea-level rise |journal=Frontiers in Earth Science |date=30 September 2015 |volume=3 |page=54 |doi=10.3389/feart.2015.00054 |bibcode=2015FrEaS...3...54H |s2cid=3256381 |doi-access=free|hdl=20.500.11850/107708 |hdl-access=free }}</ref> Less than 1% of glacier ice is in mountain glaciers, compared to 99% in Greenland and ]. However, this small size also makes mountain glaciers more vulnerable to melting than the larger ice sheets. This means they have had a disproportionate contribution to historical sea level rise and are set to contribute a smaller, but still significant fraction of sea level rise in the 21st century.<ref>{{cite journal |last1=Radić |first1=Valentina |last2=Hock |first2=Regine |title=Regionally differentiated contribution of mountain glaciers and ice caps to future sea-level rise |journal=Nature Geoscience |date=9 January 2011 |volume=4 |issue=2 |pages=91–94 |doi=10.1038/ngeo1052 |bibcode=2011NatGe...4...91R}}</ref> Observational and modelling studies of ] show they contribute 0.2-0.4 mm per year to sea level rise, averaged over the 20th century.<ref>{{cite report |doi=10.7265/N52N506F |year=2002 |last1=Dyurgerov |first1=Mark |title=Glacier Mass Balance and Regime Measurements and Analysis, 1945-2003}}</ref> The contribution for the 2012–2016 period was nearly as large as that of Greenland. It was 0.63 mm of sea level rise per year, equivalent to 34% of sea level rise from ''land ice'' sources.<ref name="Bamber2018" /> Glaciers contributed around 40% to sea level rise during the 20th century, with estimates for the 21st century of around 30%.<ref name="WCRP2018"/> | |||
# {{note|sealevel.colorado.edu.281}} {{Web reference | title=Global mean sea level calibration | url=http://sealevel.colorado.edu/calibration.html | date=2005-12-16 }} | |||
# {{note|www.grida.no.282}} {{Web reference | title= IPCC TAR, figure 11.4 | url=http://www.grida.no/climate/ipcc_tar/wg1/fig11-4.htm | date=2005-12-16 }} | |||
In 2023, a '']'' paper estimated that at {{convert|1.5|C-change|F-change}}, one quarter of mountain glacier mass would be lost by 2100 and nearly half would be lost at {{convert|4|C-change|F-change}}, contributing ~{{cvt|9|cm|in|frac=2}} and ~{{cvt|15|cm|in|frac=2}} to sea level rise, respectively. Glacier mass is disproportionately concentrated in the most resilient glaciers. So in practice this would remove 49-83% of glacier formations. It further estimated that the current likely trajectory of {{convert|2.7|C-change|F-change}} would result in the SLR contribution of ~{{cvt|11|cm|in|frac=2}} by 2100.<ref>{{Cite journal |last1=Rounce |first1=David R. |last2=Hock |first2=Regine |last3=Maussion |first3=Fabien |last4=Hugonnet |first4=Romain |last5=Kochtitzky |first5=William |last6=Huss |first6=Matthias |last7=Berthier |first7=Etienne |last8=Brinkerhoff |first8=Douglas |last9=Compagno |first9=Loris |last10=Copland |first10=Luke |last11=Farinotti |first11=Daniel |last12=Menounos |first12=Brian |last13=McNabb |first13=Robert W. |date=5 January 2023 |title=Global glacier change in the 21st century: Every increase in temperature matters |url=https://www.science.org/doi/10.1126/science.abo1324 |journal=Science |language=en |volume=79 |issue=6627 |pages=78–83 |doi=10.1126/science.abo1324 |pmid=36603094 |bibcode=2023Sci...379...78R |s2cid=255441012 |hdl=10852/108771 |hdl-access=free |access-date=8 January 2023 |archive-date=12 January 2023 |archive-url=https://web.archive.org/web/20230112211316/https://www.science.org/doi/10.1126/science.abo1324 |url-status=live }}</ref> Mountain glaciers are even more vulnerable over the longer term. In 2022, another ''Science'' paper estimated that almost no mountain glaciers could survive once warming crosses {{convert|2|C-change|F-change}}. Their complete loss is largely inevitable around {{convert|3|C-change|F-change}}. There is even a possibility of complete loss after 2100 at just {{convert|1.5|C-change|F-change}}. This could happen as early as 50 years after the tipping point is crossed, although 200 years is the most likely value, and the maximum is around 1000 years.<ref name="ArmstrongMcKay2022" /><ref name="ArmstrongMcKayExplainer" /> | |||
# {{note|www.grida.no.283}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/422.htm#tab119 | date=2005-12-16 }} | |||
# {{note|www.grida.no.284}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/408.htm | date=2005-12-16 }} | |||
=== Sea ice loss === | |||
# {{note|www.grida.no.285}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/432.htm | date=2005-12-16 }} | |||
Sea ice loss contributes very slightly to global sea level rise. If the melt water from ice floating in the sea was exactly the same as sea water then, according to ], no rise would occur. However melted sea ice contains less ] than sea water and is therefore less ], with a slightly greater volume per unit of mass. If all floating ] and ] were to melt sea level would only rise by about {{convert|4|cm|in|frac=2|abbr=on}}.<ref>{{cite journal |last1=Noerdlinger |first1=Peter D. |last2=Brower |first2=Kay R. |title=The melting of floating ice raises the ocean level |journal=Geophysical Journal International |date=July 2007 |volume=170 |issue=1 |pages=145–150 |doi=10.1111/j.1365-246X.2007.03472.x |bibcode=2007GeoJI.170..145N |doi-access=free}}</ref> | |||
# {{note|www.grida.no.286}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/fig11-13.htm | date=2005-12-16 }} | |||
] observations in gigatons per year, April 2002 to November 2014 (glaciers and ice sheets are excluded).]] | |||
# {{note|www.grida.no.287}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/409.htm | date=2005-12-16 }} | |||
# {{note|www.grida.no.288}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/434.htm#11542 | date=2005-12-16 }} | |||
=== Changes to land water storage === | |||
# {{note|www.grida.no.289}} {{Web reference | title=Climate Change 2001: The Scientific Basis (See above) | url=http://www.grida.no/climate/ipcc_tar/wg1/409.htm | date=2005-12-16 }} | |||
{{See also|Groundwater-related subsidence|}} | |||
# {{note|www.grida.no.290}} {{Web reference | title=Climate Change 2001: The Scientific Basis (See above) | url=http://www.grida.no/climate/ipcc_tar/wg1/409.htm | date=2005-12-16 }} | |||
# {{note|www.grida.no.291}} {{Web reference | title=Climate Change 2001: The Scientific Basis | url=http://www.grida.no/climate/ipcc_tar/wg1/426.htm#fig1110 | date=2005-12-16 }} | |||
Human activity impacts how much water is stored on land. ]s retain large quantities of water, which is stored on land rather than flowing into the sea, though the total quantity stored will vary from time to time. On the other hand, humans extract water from lakes, ]s and ] for drinking and ]. This often causes ]. Furthermore, the ] is influenced by climate change and ]. In the 20th century, these processes had approximately cancelled out each other's impact on sea level rise, but dam building has slowed down and is expected to stay low for the 21st century.<ref>{{cite journal |last1=Wada |first1=Yoshihide |last2=Reager |first2=John T. |last3=Chao |first3=Benjamin F. |last4=Wang |first4=Jida |last5=Lo |first5=Min-Hui |last6=Song |first6=Chunqiao |last7=Li |first7=Yuwen |last8=Gardner |first8=Alex S. |title=Recent Changes in Land Water Storage and its Contribution to Sea Level Variations |journal=Surveys in Geophysics |date=15 November 2016 |volume=38 |issue=1 |pages=131–152 |doi=10.1007/s10712-016-9399-6 |pmid=32269399 |pmc=7115037}}</ref><ref name="ipcc13" />{{rp|1155}} | |||
# {{note|www.grida.no.292}} {{Web reference | title=Climate Change 2001: The Scientific Basis (See above) | url=http://www.grida.no/climate/ipcc_tar/wg1/428.htm | date=2005-12-16 }} | |||
# {{note|www.pog.su.se.293}} {{Web reference | title=http://www.pog.su.se/sea/HP-14.%20IPCC-3.pdf | url=http://www.pog.su.se/sea/HP-14.%20IPCC-3.pdf | date=2005-12-16 }} | |||
Water redistribution caused by ] from 1993 to 2010 caused a drift of Earth's ] by {{convert|78.48|cm|in}}. This caused groundwater depletion equivalent to a global sea level rise of {{convert|6.24|mm|inches}}.<ref name=GeophysRschLtrs_20230615>{{cite journal |last1=Seo |first1=Ki-Weon |last2=Ryu |first2=Dongryeol |last3=Eom |first3=Jooyoung |last4=Jeon |first4=Taewhan |last5=Kim |first5=Jae-Seung |last6=Youm |first6=Kookhyoun |last7=Chen |first7=Jianli |last8=Wilson |first8=Clark R. |title=Drift of Earth's Pole Confirms Groundwater Depletion as a Significant Contributor to Global Sea Level Rise 1993–2010 |journal=Geophysical Research Letters |date=15 June 2023 |volume=50 |issue=12 |page=e2023GL103509 |doi=10.1029/2023GL103509 |bibcode=2023GeoRL..5003509S |s2cid=259275991 |doi-access=free |hdl=10397/109234 |hdl-access=free }}</ref> | |||
# {{note|www.grida.no.294}} {{Web reference | title=Climate Change 2001: The Scientific Basis (See above) | url=http://www.grida.no/climate/ipcc_tar/wg1/426.htm | date=2005-12-16 }} | |||
# {{note|nsidc.org.295}} {{Web reference | title=SOTC: Global Sea Level | url=http://nsidc.org/sotc/sea_level.html | date=2005-12-16 }} | |||
{{Clear}} | |||
# {{note|www.spaceref.com.296}} {{Web reference | title=Report shows movement of glacier has doubled speed : SpaceRef - Your Space Reference | url=http://www.spaceref.com/news/viewpr.html?pid=15611 | date=2005-12-16 }} | |||
# {{note|news.independent.co.uk.297}} {{Web reference | title=Independent Online Edition | url=http://news.independent.co.uk/world/environment/article301493.ece | date=2005-12-16 }} | |||
== Impacts == | |||
# {{note|www.grida.no.298}} {{Web reference | title=Climate Change 2001: The Scientific Basis (See above) | url=http://www.grida.no/climate/ipcc_tar/wg1/412.htm#tab113 | date=2005-12-16 }} | |||
{{See also|Coast#Human impacts|l1=Human impacts on coasts|Coastal development hazards|l2=|Coastal erosion|||}} | |||
# {{note|refbot299}} Snowfall-Driven Growth in East Antarctic Ice Sheet Mitigates Recent Sea-Level Rise -- Davis et al. 308 (5730): 1898 -- Science {{doi|10.1126/science.1110662}} | |||
# {{note|www.grida.no.300}} {{Web reference | title=Climate Change 2001: Impacts, Adaptation and Vulnerability | url=http://www.grida.no/climate/ipcc_tar/wg2/292.htm | date=2005-12-16 }} | |||
=== On people and societies === | |||
# {{note|www.pacificislands.cc.301}} {{Web reference | title=Pacific Islands | url=http://www.pacificislands.cc/pm122001/pmdefault.php?urlarticleid=0009 | date=2005-12-16 }} | |||
{{Multiple image|align=left |total_width=450 | |||
# {{note|outside.away.com.302}} {{Web reference | title=Tuvalu Toodle-oo : Outside Online | url=http://outside.away.com/outside/features/200212/200212_tuvalu_1.html | date=2005-12-16 }} | |||
| image1= 1950- High tide flooding, by year - NOAA tide gauges (U.S.).svg |caption1= High tide flooding, also called tidal flooding, has become much more common in the past seven decades.<ref name="N0AAHighTideFlooding201802">{{cite web |last1=Sweet |first1=William V. |last2=Dusek |first2=Greg |last3=Obeysekera |first3=Jayantha |last4=Marra |first4=John J. |title=Patterns and Projections of High Tide Flooding Along the U.S. Coastline Using a Common Impact Threshold |url=https://tidesandcurrents.noaa.gov/publications/techrpt86_PaP_of_HTFlooding.pdf |website=tidesandcurrents.NOAA.gov |publisher=National Oceanic and Atmospheric Administration (NOAA) |archive-url=https://web.archive.org/web/20221015221519/https://tidesandcurrents.noaa.gov/publications/techrpt86_PaP_of_HTFlooding.pdf |archive-date=15 October 2022 |page=4 |date=February 2018 |quote=Fig. 2b |url-status=live}}</ref> | |||
# {{note|www.cnsnews.com.303}} {{News reference | title=Climatologist Rejects 'Global Warming' as Cause for Island Evacuation -- 12/07/2005 | url=http://www.cnsnews.com/ViewCulture.asp?Page=%5CCulture%5Carchive%5C200512%5CCUL20051207a.html | author=Marc Morano | org=Cybercast News Service | urldate=2005-12-16 }} | |||
| image2= 2000- Declared flood disasters - US.svg|caption2= The number of floods declared to be disasters by the ] (FEMA) has increased, especially since 2010.<ref name=NYTimes_20241022>{{cite news |last1=Flavelle |first1=Christopher |title=America's Flooding Problem |url=https://www.nytimes.com/2024/10/22/briefing/americas-flooding-problem.html |newspaper=The New York Times |date=22 October 2024 |archive-url=https://archive.today/20241022105521/https://www.nytimes.com/2024/10/22/briefing/americas-flooding-problem.html |archive-date=22 October 2024 |url-status=live }}</ref> | |||
# {{note|www.grida.no.304}} {{Web reference | title=Climate Change 2001: The Scientific Basis (See above) | url=http://www.grida.no/climate/ipcc_tar/wg1/426.htm | date=2005-12-16 }} | |||
}} | |||
# {{note|membrane.com.305}} {{Web reference | title=Satellite Measurements of Sea Level Rise (See above) | url=http://membrane.com/sidd/sealevel.html | date=2005-12-16 }} | |||
Sea-level rise has many impacts. They include higher and more frequent high-tide and ] flooding and increased ]. Other impacts are inhibition of ] processes, more extensive coastal inundation, and changes in surface ] and ]. These can lead to a greater loss of property and coastal habitats, loss of life during floods and loss of cultural resources. There are also impacts on agriculture and ]. There can also be loss of tourism, recreation, and transport-related functions.<ref name="IPCC-2001">{{Cite report|url=https://www.ipcc.ch/site/assets/uploads/2018/03/WGI_TAR_full_report.pdf|title=TAR Climate Change 2001: The Scientific Basis|date=2001|publisher=International Panel on Climate Change, Cambridge University Press|isbn=0521-80767-0|access-date=23 July 2021|archive-date=5 December 2021|archive-url=https://web.archive.org/web/20211205084026/https://www.ipcc.ch/site/assets/uploads/2018/03/WGI_TAR_full_report.pdf|url-status=live}}</ref>{{rp|356}} ] changes such as ] or ] of low-lying coastal zones exacerbate coastal flooding impacts. Regions already vulnerable to rising sea level also struggle with coastal flooding. This washes away land and alters the landscape.<ref>{{Cite journal|last=Wu|first=Tao|date=October 2021|title=Quantifying coastal flood vulnerability for climate adaptation policy using principal component analysis|journal=Ecological Indicators|language=en|volume=129|page=108006|doi=10.1016/j.ecolind.2021.108006|bibcode=2021EcInd.12908006W|doi-access=free}}</ref> | |||
# {{note|earth.esa.int.306}} {{Web reference | title=ERS | url=http://earth.esa.int/ers/ | date=2005-12-16 }} | |||
# {{note|www.esa.int.307}} {{Web reference | title=ESA - Observing the Earth - ERS overview | url=http://www.esa.int/export/esaEO/SEMGWH2VQUD_index_0_m.html | date=2005-12-16 }} | |||
Changes in emissions are likely to have only a small effect on the extent of sea level rise by 2050.<ref name="us nrc 2011 long term slr" /> So projected sea level rise could put tens of millions of people at risk by then. Scientists estimate that 2050 levels of sea level rise would result in about 150 million people under the water line during high tide. About 300 million would be in places flooded every year. This projection is based on the distribution of population in 2010. It does not take into account the effects of ] and ]. These figures are 40 million and 50 million more respectively than the numbers at risk in 2010.<ref name="Kulp2019">{{cite journal |last1=Kulp |first1=Scott A. |last2=Strauss |first2=Benjamin H. |title=New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding |journal=Nature Communications |date=29 October 2019 |volume=10 |issue=1 |page=4844 |doi=10.1038/s41467-019-12808-z |pmid=31664024 |pmc=6820795 |bibcode=2019NatCo..10.4844K}}</ref><ref>{{cite news|url=https://www.ecowatch.com/sea-level-rise-predictions-2641159739.html|title=300 Million People Worldwide Could Suffer Yearly Flooding by 2050|last1=Rosane|first1=Olivia|date=October 30, 2019|access-date=31 October 2019|agency=Ecowatch|archive-date=9 December 2019|archive-url=https://web.archive.org/web/20191209224048/https://www.ecowatch.com/sea-level-rise-predictions-2641159739.html|url-status=live}}</ref> By 2100, there would be another 40 million people under the water line during high tide if sea level rise remains low. This figure would be 80 million for a high estimate of median sea level rise.<ref name="Kulp2019" /> Ice sheet processes under the highest ] would result in sea level rise of well over {{convert|1|m|ft|frac=4|spell=in}} by 2100. This could be as much as over {{convert|2|m|ft|frac=2|spell=in}},<ref name="NOAA-2022" /><ref name="IPCC_2021_WGI_SPM" />{{rp|TS-45}} This could result in as many as 520 million additional people ending up under the water line during high tide and 640 million in places flooded every year, compared to the 2010 population distribution.<ref name="Kulp2019" /> | |||
# {{note|sealevel.jpl.nasa.gov.308}} {{Web reference | title=Ocean Surface Topography from Space-Science | url=http://sealevel.jpl.nasa.gov/science/tandem.html | date=2005-12-16 }} | |||
] | |||
# {{note|www.earth.nasa.gov.309}} {{Web reference | title=40+ Years of Earth Science * TOPEX/Poseidon * | url=http://www.earth.nasa.gov/history/topex/topex.html | date=2005-12-16 }} | |||
Over the longer term, coastal areas are particularly vulnerable to rising sea levels. They are also vulnerable to changes in the frequency and intensity of storms, increased precipitation, and rising ]s. Ten percent of the world's population live in coastal areas that are less than {{Convert|10|m|ft}} above sea level. Two thirds of the world's cities with over five million people are located in these low-lying coastal areas.<ref>{{cite journal |last1=McGranahan |first1=Gordon |last2=Balk |first2=Deborah |last3=Anderson |first3=Bridget |title=The rising tide: assessing the risks of climate change and human settlements in low elevation coastal zones |journal=Environment and Urbanization |date=29 June 2016 |volume=19 |issue=1 |pages=17–37 |doi=10.1177/0956247807076960 |s2cid=154588933}}</ref> About 600 million people live directly on the coast around the world.<ref>{{cite news |last1=Sengupta |first1=Somini |others=Photographer: Chang W. Lee |title=A Crisis Right Now: San Francisco and Manila Face Rising Seas |url=https://www.nytimes.com/interactive/2020/02/13/climate/manila-san-francisco-sea-level-rise.html |access-date=4 March 2020 |work=The New York Times |date=13 February 2020 |archive-date=7 May 2020 |archive-url=https://web.archive.org/web/20200507112647/https://www.nytimes.com/interactive/2020/02/13/climate/manila-san-francisco-sea-level-rise.html |url-status=live }}</ref> Cities such as ], ], ] and ] will be especially vulnerable later in the century under warming of 3 °C (5.4 °F). This is close to the current trajectory.<ref name="Holder-2017">{{Cite news|last1=Holder|first1=Josh|last2=Kommenda|first2=Niko|last3=Watts|first3=Jonathan|date=3 November 2017|title=The three-degree world: cities that will be drowned by global warming|work=The Guardian|url=https://www.theguardian.com/cities/ng-interactive/2017/nov/03/three-degree-world-cities-drowned-global-warming|access-date=2018-12-28|archive-date=2020-01-03|archive-url=https://web.archive.org/web/20200103081510/https://www.theguardian.com/cities/ng-interactive/2017/nov/03/three-degree-world-cities-drowned-global-warming|url-status=live}}</ref><ref name="CAT" /> ]-based research had established in 2021 that 267 million people worldwide lived on land less than {{cvt|2|m|ft|frac=2}} above sea level. With a {{cvt|1|m|ft|frac=2}} sea level rise and zero population growth, that could increase to 410 million people.<ref>{{Cite web|last=Storer|first=Rhi|date=2021-06-29|title=Up to 410 million people at risk from sea level rises – study|url=http://www.theguardian.com/environment/2021/jun/29/risk-from-sea-level-rises-unless-emissions-reduced|access-date=2021-07-01|website=The Guardian|language=en|archive-date=2023-05-18|archive-url=https://web.archive.org/web/20230518021028/https://www.theguardian.com/environment/2021/jun/29/risk-from-sea-level-rises-unless-emissions-reduced|url-status=live}}</ref><ref>{{Cite journal|last1=Hooijer|first1=A.|last2=Vernimmen|first2=R.|date=2021-06-29|title=Global LiDAR land elevation data reveal greatest sea-level rise vulnerability in the tropics|journal=Nature Communications|language=en|volume=12|issue=1|page=3592|doi=10.1038/s41467-021-23810-9|pmid=34188026|pmc=8242013|bibcode=2021NatCo..12.3592H|issn=2041-1723}}</ref> | |||
# {{note|ibis.grdl.noaa.gov.310}} {{Web reference | title=http://ibis.grdl.noaa.gov/SAT/hist/tp_products/dev/Fall_2001_Deviation.gif | url=http://ibis.grdl.noaa.gov/SAT/hist/tp_products/dev/Fall_2001_Deviation.gif | date=2005-12-16 }} | |||
# {{note|earth.esa.int.311}} {{Web reference | title=Altimeter design | url=http://earth.esa.int/rootcollection/eeo4.10075/altimeter_design.html | date=2005-12-16 }} | |||
Potential disruption of sea trade and migrations could impact people living further inland. United Nations Secretary-General ] warned in 2023 that sea level rise risks causing ] on a "biblical scale".<ref>{{Cite news|last1=Carrington|first1=Damian|date=14 February 2023|title=Rising seas threaten 'mass exodus on a biblical scale', UN chief warns|work=The Guardian|url=https://www.theguardian.com/environment/2023/feb/14/rising-seas-threaten-mass-exodus-on-a-biblical-scale-un-chief-warns|access-date=2023-02-25|archive-date=2023-07-06|archive-url=https://web.archive.org/web/20230706040859/https://www.theguardian.com/environment/2023/feb/14/rising-seas-threaten-mass-exodus-on-a-biblical-scale-un-chief-warns|url-status=live}}</ref> Sea level rise will inevitably affect ]s, but there is limited research on this. There is insufficient knowledge about the investments necessary to protect ports currently in use. This includes protecting current facilities before it becomes more reasonable to build new ports elsewhere.<ref>{{Cite journal|last1=Xia|first1=Wenyi|last2=Lindsey|first2=Robin|date=October 2021|title=Port adaptation to climate change and capacity investments under uncertainty|url=https://linkinghub.elsevier.com/retrieve/pii/S0191261521001600|journal=Transportation Research Part B: Methodological|language=en|volume=152|pages=180–204|doi=10.1016/j.trb.2021.08.009|bibcode=2021TRPB..152..180X|s2cid=239647501|access-date=2021-12-17|archive-date=2023-01-02|archive-url=https://web.archive.org/web/20230102220943/https://linkinghub.elsevier.com/retrieve/pii/S0191261521001600|url-status=live}}</ref><ref>{{Cite web|title=Chapter 4: Sea Level Rise and Implications for Low-Lying Islands, Coasts and Communities — Special Report on the Ocean and Cryosphere in a Changing Climate|url=https://www.ipcc.ch/srocc/chapter/chapter-4-sea-level-rise-and-implications-for-low-lying-islands-coasts-and-communities/|access-date=2021-12-17|archive-date=2023-09-02|archive-url=https://web.archive.org/web/20230902021918/https://www.ipcc.ch/srocc/chapter/chapter-4-sea-level-rise-and-implications-for-low-lying-islands-coasts-and-communities/|url-status=live}}</ref> Some coastal regions are rich agricultural lands. Their loss to the sea could cause ]s. This is a particularly acute issue for ]s such as ] in ] and ] and ]s in Vietnam. Saltwater intrusion into the soil and ] water has a disproportionate effect on them.<ref name="Michaelson-2018" /><ref name="Nagothu-2017">{{Cite web |last=Nagothu |first=Udaya Sekhar |date=2017-01-18 |title=Food security threatened by sea-level rise |url=https://www.nibio.no/nyheter/food-security-threatened-by-sea-level-rise |access-date=2018-10-21 |publisher=Nibio |archive-date=2020-07-31 |archive-url=https://web.archive.org/web/20200731214557/https://www.nibio.no/nyheter/food-security-threatened-by-sea-level-rise |url-status=live }}</ref> | |||
# {{note|sealevel.jpl.nasa.gov.312}} {{Web reference | title=Ocean Surface Topography from Space-Technology | url=http://sealevel.jpl.nasa.gov/technology/instrument-altimeter.html | date=2005-12-16 }} | |||
# {{note|www.jason.oceanobs.com.313}} {{Web reference | title=Aviso/Altimetry - How altimetry works | url=http://www.jason.oceanobs.com/html/alti/principe_uk.html | date=2005-12-16 }} | |||
===On ecosystems=== | |||
# {{note|sealevel.jpl.nasa.gov.314}} {{Web reference | title=Ocean Surface Topography from Space-Science | url=http://sealevel.jpl.nasa.gov/science/invest-cazenave.html | date=2005-12-16 }} | |||
{{See also|Extinction risk from climate change}} | |||
# {{note|sealevel.jpl.nasa.gov.315}} {{Web reference | title=Ocean Surface Topography from Space-Technology | url=http://sealevel.jpl.nasa.gov/technology/technology.html | date=2005-12-16 }} | |||
], the first known mammal species to go extinct due to sea level rise.]] | |||
# {{note|ams.allenpress.com.316}} {{Web reference | title=Monitoring the Stability of Satellite Altimeters with Tide Gauges | url=http://ams.allenpress.com/amsonline/?request=get-abstract&issn=1520-0426&volume=015&issue=03&page=0721 | date=2005-12-16 }} | |||
Flooding and soil/water salinization threaten the habitats of ]al plants, birds, and freshwater/] fish when seawater reaches inland.<ref name="National Geographic-2017">{{Cite web|url=https://www.nationalgeographic.com/environment/global-warming/sea-level-rise/|archive-url=https://web.archive.org/web/20170117004107/http://www.nationalgeographic.com/environment/global-warming/sea-level-rise/|archive-date=January 17, 2017|title=Sea Level Rise|date=January 13, 2017|website=National Geographic}}</ref> When coastal ] areas become inundated with saltwater to the point no trees can survive the resulting habitats are called ]s.<ref>{{cite web|url=http://grist.org/article/ghost-forests-are-eerie-evidence-of-rising-seas/|title=Ghost forests are eerie evidence of rising seas|date=18 September 2016|website=Grist.org|access-date=2017-05-17|archive-date=2023-03-29|archive-url=https://web.archive.org/web/20230329190328/https://grist.org/article/ghost-forests-are-eerie-evidence-of-rising-seas/|url-status=live}}</ref><ref>{{cite web|url=http://e360.yale.edu/features/ghost_forest_rising_sea_levels_killing_coastal_woodlands|title=How Rising Seas Are Killing Southern U.S. Woodlands - Yale E360|website=e360.yale.edu|access-date=2017-05-17|archive-date=2023-08-19|archive-url=https://web.archive.org/web/20230819015407/https://e360.yale.edu/features/ghost_forest_rising_sea_levels_killing_coastal_woodlands|url-status=live}}</ref> Starting around 2050, some nesting sites in ], ], ] and the island of ] for ], ], ], ] and ]s are expected to be flooded. The proportion will increase over time.<ref>{{Cite journal |last1=Rivas |first1=Marga L. |last2=Rodríguez-Caballero |first2=Emilio |last3=Esteban |first3=Nicole |last4=Carpio |first4=Antonio J. |last5=Barrera-Vilarmau |first5=Barbara |last6=Fuentes |first6=Mariana M. P. B. |last7=Robertson |first7=Katharine |last8=Azanza |first8=Julia |last9=León |first9=Yolanda |last10=Ortega |first10=Zaida |date=2023-04-20 |title=Uncertain future for global sea turtle populations in face of sea level rise |journal=Scientific Reports |language=en |volume=13 |issue=1 |page=5277 |doi=10.1038/s41598-023-31467-1 |pmid=37081050 |pmc=10119306 |bibcode=2023NatSR..13.5277R |issn=2045-2322}}</ref> In 2016, ] islet in the ] was inundated. This flooded the habitat of a rodent named ].<ref>{{cite web|url=http://www.australiangeographic.com.au/news/2016/06/extinct-bramble-cay-melomys|title=Extinct: Bramble Cay melomys|last=Smith|first=Lauren|date=2016-06-15|website=Australian Geographic|access-date=2016-06-17|archive-date=2020-08-17|archive-url=https://web.archive.org/web/20200817201358/https://www.australiangeographic.com.au/news/2016/06/extinct-bramble-cay-melomys/|url-status=live}}</ref> It was officially declared extinct in 2019.<ref>{{Cite web|url=https://www.smh.com.au/environment/climate-change/our-little-brown-rat-first-climate-change-caused-mammal-extinction-20190219-p50yry.html|title='Our little brown rat': first climate change-caused mammal extinction|last=Hannam|first=Peter|date=2019-02-19|website=The Sydney Morning Herald|language=en|access-date=2019-06-25|archive-date=2020-06-17|archive-url=https://web.archive.org/web/20200617054703/https://www.smh.com.au/environment/climate-change/our-little-brown-rat-first-climate-change-caused-mammal-extinction-20190219-p50yry.html|url-status=live}}</ref> | |||
# {{note|ams.allenpress.com.317}} {{Web reference | title=Monitoring the Stability of Satellite Altimeters with Tide Gauges (See above) | url=http://ams.allenpress.com/amsonline/?request=get-abstract&issn=1520-0426&volume=015&issue=03&page=0721 | date=2005-12-16 }} | |||
] | |||
# {{note|earth.esa.int.318}} {{Web reference | title=http://earth.esa.int/pcs/ers/ra/articles/soc-esafrv.pdf | url=http://earth.esa.int/pcs/ers/ra/articles/soc-esafrv.pdf | date=2005-12-16 }} | |||
Some ecosystems can move inland with the high-water mark. But natural or artificial barriers prevent many from migrating. This coastal narrowing is sometimes called 'coastal squeeze' when it involves human-made barriers. It could result in the loss of habitats such as ]s and ]es.<ref name="birdlife-2015">{{Cite web|url=http://datazone.birdlife.org/sea-level-rise-poses-a-major-threat-to-coastal-ecosystems-and-the-biota-they-support|title=Sea level rise poses a major threat to coastal ecosystems and the biota they support|date=2015|website=birdlife.org|publisher=Birdlife International|access-date=2018-09-06|archive-date=2019-05-20|archive-url=https://web.archive.org/web/20190520130929/http://datazone.birdlife.org/sea-level-rise-poses-a-major-threat-to-coastal-ecosystems-and-the-biota-they-support|url-status=live}}</ref><ref>{{cite journal |last1=Pontee |first1=Nigel |title=Defining coastal squeeze: A discussion |journal=Ocean & Coastal Management |date=November 2013 |volume=84 |pages=204–207 |doi=10.1016/j.ocecoaman.2013.07.010 |bibcode=2013OCM....84..204P}}</ref> ] ecosystems on the mudflats of tropical coasts nurture high ]. They are particularly vulnerable due to mangrove plants' reliance on breathing roots or ]. These will be submerged if the rate is too rapid for them to migrate upward. This would result in the loss of an ecosystem.<ref>{{Cite web|url=https://www.nrc.govt.nz/for-schools/school-information-packs/mangroves/|title=Mangroves - Northland Regional Council|website=www.nrc.govt.nz|access-date=2020-10-28|archive-date=2023-06-02|archive-url=https://web.archive.org/web/20230602174756/https://www.nrc.govt.nz/for-schools/school-information-packs/mangroves|url-status=live}}</ref><ref name="High mangrove density enhances surf">{{cite journal |last1=Kumara |first1=M. P. |last2=Jayatissa |first2=L. P. |last3=Krauss |first3=K. W. |last4=Phillips |first4=D. H. |last5=Huxham |first5=M. |title=High mangrove density enhances surface accretion, surface elevation change, and tree survival in coastal areas susceptible to sea-level rise |journal=Oecologia |pages=545–553 |date=2010|volume=164 |issue=2 |doi=10.1007/s00442-010-1705-2 |jstor=40864709 |pmid=20593198 |bibcode=2010Oecol.164..545K |s2cid=6929383}}</ref><ref>{{cite journal |last1=Krauss |first1=Ken W. |last2=McKee |first2=Karen L. |last3=Lovelock |first3=Catherine E. |last4=Cahoon |first4=Donald R. |last5=Saintilan |first5=Neil |last6=Reef |first6=Ruth |last7=Chen |first7=Luzhen |title=How mangrove forests adjust to rising sea level |journal=New Phytologist |date=April 2014 |volume=202 |issue=1 |pages=19–34 |doi=10.1111/nph.12605 |pmid=24251960 |bibcode=2014NewPh.202...19K |url=https://digitalcommons.unl.edu/usgsstaffpub/986 |access-date=2019-10-31 |archive-date=2020-08-06 |archive-url=https://web.archive.org/web/20200806191108/https://digitalcommons.unl.edu/usgsstaffpub/986/ |url-status=live }}</ref><ref name="A Conceptual Model for the Response">{{cite journal|last1=Soares|first1=M.L.G.|date=2009|title=A Conceptual Model for the Responses of Mangrove Forests to Sea Level Rise|journal=Journal of Coastal Research|pages=267–271|jstor=25737579}}</ref> Both mangroves and ]es protect against storm surges, waves and tsunamis, so their loss makes the effects of sea level rise worse.<ref>{{cite journal |last1=Crosby |first1=Sarah C. |last2=Sax |first2=Dov F. |last3=Palmer |first3=Megan E. |last4=Booth |first4=Harriet S. |last5=Deegan |first5=Linda A. |last6=Bertness |first6=Mark D. |last7=Leslie |first7=Heather M. |title=Salt marsh persistence is threatened by predicted sea-level rise |journal=Estuarine, Coastal and Shelf Science |date=November 2016 |volume=181 |pages=93–99 |doi=10.1016/j.ecss.2016.08.018 |bibcode=2016ECSS..181...93C |doi-access=free}}</ref><ref>{{cite web|url=https://www.nature.org/media/oceansandcoasts/mangroves-for-coastal-defence.pdf|title=Mangroves for coastal defence. Guidelines for coastal managers & policy makers|author1=Spalding, M.|author2=McIvor, A.|date=2014|publisher=] and ]|author3=Tonneijck, F.H.|author4=Tol, S.|author5=van Eijk, P.|access-date=2018-09-07|archive-date=2019-11-12|archive-url=https://web.archive.org/web/20191112063642/http://www.nature.org/media/oceansandcoasts/mangroves-for-coastal-defence.pdf|url-status=live}}</ref> Human activities such as dam building may restrict sediment supplies to wetlands. This would prevent natural adaptation processes. The loss of some tidal marshes is unavoidable as a consequence.<ref>{{cite journal |last1=Weston |first1=Nathaniel B. |title=Declining Sediments and Rising Seas: an Unfortunate Convergence for Tidal Wetlands |journal=Estuaries and Coasts |date=16 July 2013 |volume=37 |issue=1 |pages=1–23 |doi=10.1007/s12237-013-9654-8 |s2cid=128615335}}</ref> | |||
# {{note|ibis.grdl.noaa.gov.319}} {{Web reference | title=T/P versus Pacific Gauges | url=http://ibis.grdl.noaa.gov/SAT/hist/tp_gauge/index.html | date=2005-12-16 }} | |||
# {{note|sealevel.colorado.edu.320}} {{Web reference | title=Global mean sea level calibration (See above) | url=http://sealevel.colorado.edu/calibration.html | date=2005-12-16 }} | |||
]s are important for bird and fish life. They need to grow vertically to remain close to the sea surface in order to get enough energy from sunlight. The corals have so far been able to keep up the vertical growth with the rising seas, but might not be able to do so in the future.<ref>{{Cite book|title=Climate Change 2014: Impacts, Adaptation, and Vulnerability.|last1=Wong|first1=Poh Poh|last2=Losado|first2=I.J.|last3=Gattuso|first3=J.-P.|last4=Hinkel|first4=Jochen|publisher=Cambridge University Press|year=2014|location=New York|chapter=Coastal Systems and Low-Lying Areas|chapter-url=http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap5_FINAL.pdf|access-date=2018-10-07|archive-date=2018-11-23|archive-url=https://web.archive.org/web/20181123125554/http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap5_FINAL.pdf}}</ref> | |||
# {{note|sealevel.jpl.nasa.gov.321}} {{Web reference | title=The dynamics of short-term ocean climate variability | url=http://sealevel.jpl.nasa.gov/science/invest-chelton.html | date=2005-12-16 }} | |||
# {{note|ibis.grdl.noaa.gov.322}} {{Web reference | title= Geosat Follow-On @ NOAA/LSA | url=http://ibis.grdl.noaa.gov/SAT/gfo/ | date=2005-12-16 }} | |||
== Regional variations == | |||
# {{note|gfo.bmpcoe.org.323}} {{Web reference | title= NAVY GEOSAT FOLLOW-ON (GFO) ALTIMETRY MISSION | url=http://gfo.bmpcoe.org/Gfo/default.htm | date=2005-12-16 }} | |||
{{Further|Relative sea level|Sinking cities}} | |||
# {{note|gfo.wff.nasa.gov.324}} {{Web reference | title= NASA WFF Geosat Follow-On | url=http://gfo.wff.nasa.gov/ | date=2005-12-16 }} | |||
] is one example<ref>{{Cite journal |last1=Ohenhen |first1=Leonard O. |last2=Shirzaei |first2=Manoochehr |last3=Ojha |first3=Chandrakanta |last4=Kirwan |first4=Matthew L. |date=11 April 2023 |title=Hidden vulnerability of US Atlantic coast to sea-level rise due to vertical land motion |journal=Nature Communications |volume=14 |issue=1 |page=2038 |bibcode=2023NatCo..14.2038O |doi=10.1038/s41467-023-37853-7 |pmc=10090057 |pmid=37041168}}</ref>]] | |||
# {{note|nng.esoc.esa.de.325}} {{Web reference | title= Sea Level Analysis from ERS Altimetry | url=http://nng.esoc.esa.de//ers/alti.html | date=2005-12-16 }} | |||
# {{note|www.jason.oceanobs.com.326}} {{Web reference | title= Ssalto/Duacs multimission altimeter products | url=http://www.jason.oceanobs.com/html/donnees/duacs/welcome_uk.html | date=2005-12-16 }} | |||
When a glacier or ice sheet melts, it loses mass. This reduces its gravitational pull. In some places near current and former glaciers and ice sheets, this has caused water levels to drop. At the same time water levels will increase more than average further away from the ice sheet. Thus ice loss in ] affects regional sea level differently than the equivalent loss in ].<ref name="Rovere-2016">{{cite journal |last1=Rovere |first1=Alessio |last2=Stocchi |first2=Paolo |last3=Vacchi |first3=Matteo |date=2 August 2016 |title=Eustatic and Relative Sea Level Changes |journal=Current Climate Change Reports |volume=2 |issue=4 |pages=221–231 |bibcode=2016CCCR....2..221R |doi=10.1007/s40641-016-0045-7 |s2cid=131866367 |doi-access=free}}</ref> On the other hand, the Atlantic is warming at a faster pace than the Pacific. This has consequences for Europe and the ]. The East Coast sea level is rising at 3–4 times the global average.<ref>{{cite news |year=2016 |title=Why the U.S. East Coast could be a major 'hotspot' for rising seas |url=https://www.washingtonpost.com/news/energy-environment/wp/2016/02/01/why-the-u-s-east-coast-could-be-a-major-hotspot-for-sea-level-rise/ |url-status=live |archive-url=https://web.archive.org/web/20200331080306/https://www.washingtonpost.com/news/energy-environment/wp/2016/02/01/why-the-u-s-east-coast-could-be-a-major-hotspot-for-sea-level-rise/ |archive-date=2020-03-31 |access-date=2016-02-04 |newspaper=The Washington Post}}</ref> Scientists have linked extreme regional sea level rise on the US Northeast Coast to the downturn of the ] (AMOC).<ref>{{cite news |last1=Yin |first1=Jianjun |last2=Griffies |first2=Stephen |name-list-style=amp |date=March 25, 2015 |title=Extreme sea level rise event linked to AMOC downturn |url=https://usclivar.org/research-highlights/extreme-sea-level-rise-event-linked-amoc-downturn |url-status=live |archive-url=https://web.archive.org/web/20230127023140/https://usclivar.org/research-highlights/extreme-sea-level-rise-event-linked-amoc-downturn |archive-date=January 27, 2023 |access-date=November 23, 2021 |publisher=CLIVAR}}</ref> | |||
Many ]s, urban conglomerations, and agricultural regions stand on ]s. Here land subsidence contributes to much higher ] rise. Unsustainable extraction of ] and oil and gas is one cause. ]s and other flood management practices are another. They prevent sediments from accumulating. These would otherwise compensate for the natural settling of deltaic soils.<ref>{{Cite journal |last1=Tessler |first1=Z. D. |last2=Vörösmarty |first2=C. J. |last3=Grossberg |first3=M. |last4=Gladkova |first4=I. |last5=Aizenman |first5=H. |last6=Syvitski |first6=J. P. M. |last7=Foufoula-Georgiou |first7=E. |date=2015-08-07 |title=Profiling risk and sustainability in coastal deltas of the world |url=https://cloudfront.escholarship.org/dist/prd/content/qt46n8t5mp/qt46n8t5mp.pdf |url-status=live |journal=Science |volume=349 |issue=6248 |pages=638–643 |bibcode=2015Sci...349..638T |doi=10.1126/science.aab3574 |issn=0036-8075 |pmid=26250684 |s2cid=12295500 |archive-url=https://web.archive.org/web/20180724000157/https://cloudfront.escholarship.org/dist/prd/content/qt46n8t5mp/qt46n8t5mp.pdf |archive-date=2018-07-24 |access-date=2019-09-02}}</ref>{{rp|638}}<ref name="Bucx 2010">{{cite book |last=Bucx |first=Tom |title=Comparative assessment of the vulnerability and resilience of 10 deltas: synthesis report |date=2010 |publisher=Deltares |isbn=978-94-90070-39-7 |publication-place=Delft, Netherlands |oclc=768078077}}</ref>{{rp|88}} | |||
Estimates for total human-caused subsidence in the ] (Netherlands) are {{Cvt|3-4|m|ft|0}}, over {{Cvt|3|m|ft|0}} in urban areas of the ] (]), and over {{Cvt|9|m|ft|0}} in the ].<ref name="Bucx 2010" />{{rp|81–90}} On the other hand, relative sea level around the ] in ] and the northern ] is falling due to post-glacial isostatic rebound.<ref>{{Cite journal |last1=Cazenave |first1=Anny |author-link=Anny Cazenave |last2=Nicholls |first2=Robert J. |date=2010 |title=Sea-Level Rise and Its Impact on Coastal Zones |journal=Science |volume=328 |issue=5985 |pages=1517–1520 |bibcode=2010Sci...328.1517N |doi=10.1126/science.1185782 |issn=0036-8075 |pmid=20558707 |s2cid=199393735}}</ref> | |||
== Adaptation == | |||
{{further|Climate change adaptation|coastal management}} | |||
], the largest barrier of the Dutch ].]] | |||
] can slow and stabilize the rate of sea level rise after 2050. This would greatly reduce its costs and damages, but cannot stop it outright. So ] to sea level rise is inevitable.<ref>Cooley, S., D. Schoeman, L. Bopp, P. Boyd, S. Donner, D.Y. Ghebrehiwet, S.-I. Ito, W. Kiessling, P. Martinetto, E. Ojea, M.-F. Racault, B. Rost, and M. Skern-Mauritzen, 2022: {{Webarchive|url=https://web.archive.org/web/20230712212111/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_FinalDraft_Chapter03.pdf |date=2023-07-12 }}. In: ''Climate Change 2022: Impacts, Adaptation, and Vulnerability.'' Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change . Cambridge University Press. In Press. - Cross-Chapter Box SLR: Sea Level Rise</ref>{{rp||page=3–127}} The simplest approach is to stop development in vulnerable areas and ultimately move people and ] away from them. Such ''retreat'' from sea level rise often results in the loss of livelihoods. The displacement of newly impoverished people could burden their new homes and accelerate social tensions.<ref>{{Cite journal |last1=Dasgupta |first1=Susmita |last2=Wheeler |first2=David |last3=Bandyopadhyay |first3=Sunando |last4=Ghosh |first4=Santadas |last5=Roy |first5=Utpal |date=February 2022 |title=Coastal dilemma: Climate change, public assistance and population displacement |url=https://linkinghub.elsevier.com/retrieve/pii/S0305750X21003223 |journal=World Development |language=en |volume=150 |page=105707 |doi=10.1016/j.worlddev.2021.105707 |issn=0305-750X |s2cid=244585347 |access-date=2021-12-17 |archive-date=2022-11-10 |archive-url=https://web.archive.org/web/20221110212423/https://linkinghub.elsevier.com/retrieve/pii/S0305750X21003223 |url-status=live }}</ref> | |||
It is possible to avoid or at least delay the ''retreat'' from sea level rise with enhanced ''protections.'' These include ]s, ]s or improved natural defenses.<ref name="Thomsen-2012" /> Other options include updating ] to reduce damage from floods, addition of storm water valves to address more frequent and severe flooding at high tide,<ref name="US EPA">{{cite web |date=2 May 2016 |title=Climate Adaptation and Sea Level Rise |url=https://www.epa.gov/arc-x/climate-adaptation-and-sea-level-rise |website=US EPA, Climate Change Adaptation Resource Center (ARC-X) |language=en |access-date=13 March 2020 |archive-date=8 May 2020 |archive-url=https://web.archive.org/web/20200508055630/https://www.epa.gov/arc-x/climate-adaptation-and-sea-level-rise |url-status=live }}</ref> or cultivating crops more tolerant of saltwater in the soil, even at an increased cost.<ref name="Nagothu-2017" /><ref name="Thomsen-2012" /><ref name="Fletcher-2013">{{cite journal |last1=Fletcher |first1=Cameron |date=2013 |title=Costs and coasts: an empirical assessment of physical and institutional climate adaptation pathways |url=https://apo.org.au/node/34006 |journal=Apo |access-date=2019-10-31 |archive-date=2020-07-31 |archive-url=https://web.archive.org/web/20200731224002/https://apo.org.au/node/34006 |url-status=live }}</ref> These options divide into ''hard'' and ''soft'' adaptation. Hard adaptation generally involves large-scale changes to human societies and ecological systems. It often includes the construction of capital-intensive infrastructure. Soft adaptation involves strengthening ] and local community adaptation. This usually involves simple, modular and locally owned technology. The two types of adaptation may be complementary or mutually exclusive.<ref name="Fletcher-2013" /><ref>{{Cite journal |last=Sovacool |first=Benjamin K. |date=2011 |title=Hard and soft paths for climate change adaptation |url=http://www.adaptation-undp.org/sites/default/files/downloads/sovacool-cp-hardsoft.pdf |url-status=dead |journal=Climate Policy |volume=11 |issue=4 |pages=1177–1183 |bibcode=2011CliPo..11.1177S |doi=10.1080/14693062.2011.579315 |s2cid=153384574 |archive-url=https://web.archive.org/web/20200710010054/https://www.adaptation-undp.org/sites/default/files/downloads/sovacool-cp-hardsoft.pdf |archive-date=2020-07-10 |access-date=2018-09-02}}</ref> Adaptation options often require significant investment. But the costs of doing nothing are far greater. One example would involve adaptation against flooding. Effective adaptation measures could reduce future annual costs of flooding in 136 of the world's largest coastal cities from $1 trillion by 2050 without adaptation to a little over $60 billion annually. The cost would be $50 billion per year.<ref>{{cite web |date=18 August 2013 |title=Coastal cities face rising risk of flood losses, study says |url=https://phys.org/news/2013-08-coastal-cities-losses.html |access-date=17 April 2023 |publisher=Phys.org |archive-date=22 April 2023 |archive-url=https://web.archive.org/web/20230422005012/https://phys.org/news/2013-08-coastal-cities-losses.html |url-status=live }}</ref><ref>{{cite journal |last1=Hallegatte |first1=Stephane |last2=Green |first2=Colin |last3=Nicholls |first3=Robert J. |last4=Corfee-Morlot |first4=Jan |date=18 August 2013 |title=Future flood losses in major coastal cities |url=https://www.nature.com/articles/nclimate1979 |journal=Nature Climate Change |language=en |volume=3 |issue=9 |pages=802–806 |bibcode=2013NatCC...3..802H |doi=10.1038/nclimate1979 |access-date=17 April 2023 |archive-date=26 August 2023 |archive-url=https://web.archive.org/web/20230826224546/https://www.nature.com/articles/nclimate1979 |url-status=live }}</ref> Some experts argue that retreat from the coast would have a lower impact on the ] of ] and ] then attempting to protect every coastline, in the case of very high sea level rise.<ref>{{cite journal |last1=Bachner |first1=Gabriel |last2=Lincke |first2=Daniel |last3=Hinkel |first3=Jochen |date=29 September 2022 |title=The macroeconomic effects of adapting to high-end sea-level rise via protection and migration |journal=Nature Communications |language=en |volume=13 |issue=1 |page=5705 |bibcode=2022NatCo..13.5705B |doi=10.1038/s41467-022-33043-z |pmc=9522673 |pmid=36175422}}</ref> | |||
].<ref name="Hurk2022" />]] | |||
To be successful, adaptation must anticipate sea level rise well ahead of time. As of 2023, the global state of adaptation planning is mixed. A survey of 253 planners from 49 countries found that 98% are aware of sea level rise projections, but 26% have not yet formally integrated them into their policy documents. Only around a third of respondents from Asian and South American countries have done so. This compares with 50% in Africa, and over 75% in Europe, Australasia and North America. Some 56% of all surveyed planners have plans which account for 2050 and 2100 sea level rise. But 53% use only a single projection rather than a range of two or three projections. Just 14% use four projections, including the one for "extreme" or "high-end" sea level rise.<ref>{{cite journal |last1=Hirschfeld |first1=Daniella |last2=Behar |first2=David |last3=Nicholls |first3=Robert J. |last4=Cahill |first4=Niamh |last5=James |first5=Thomas |last6=Horton |first6=Benjamin P. |last7=Portman |first7=Michelle E. |last8=Bell |first8=Rob |last9=Campo |first9=Matthew |last10=Esteban |first10=Miguel |last11=Goble |first11=Bronwyn |last12=Rahman |first12=Munsur |last13=Appeaning Addo |first13=Kwasi |last14=Chundeli |first14=Faiz Ahmed |last15=Aunger |first15=Monique |date=3 April 2023 |title=Global survey shows planners use widely varying sea-level rise projections for coastal adaptation |journal=Communications Earth & Environment |language=en |volume=4 |issue=1 |page=102 |bibcode=2023ComEE...4..102H |doi=10.1038/s43247-023-00703-x |doi-access=free |last16=Babitsky |first16=Orly |last17=Beal |first17=Anders |last18=Boyle |first18=Ray |last19=Fang |first19=Jiayi |last20=Gohar |first20=Amir |last21=Hanson |first21=Susan |last22=Karamesines |first22=Saul |last23=Kim |first23=M. J. |last24=Lohmann |first24=Hilary |last25=McInnes |first25=Kathy |last26=Mimura |first26=Nobuo |last27=Ramsay |first27=Doug |last28=Wenger |first28=Landis |last29=Yokoki |first29=Hiromune|pmid=38665203 |pmc=11041751}} ] Text and images are available under a ].</ref> Another study found that over 75% of regional sea level rise assessments from the ] and ] included at least three estimates. These are usually ], RCP4.5 and RCP8.5, and sometimes include extreme scenarios. But 88% of projections from the ] had only a single estimate. Similarly, no assessment from the South went beyond 2100. By contrast 14 assessments from the West went up to 2150, and three from the Northeast went to 2200. 56% of all localities were also found to underestimate the upper end of sea level rise relative to ].<ref>{{cite journal |last1=Garner |first1=Andra J. |last2=Sosa |first2=Sarah E. |last3=Tan |first3=Fangyi |last4=Tan |first4=Christabel Wan Jie |last5=Garner |first5=Gregory G. |last6=Horton |first6=Benjamin P. |date=23 January 2023 |title=Evaluating Knowledge Gaps in Sea-Level Rise Assessments From the United States |journal=Earth's Future |volume=11 |issue=2 |pages=e2022EF003187 |bibcode=2023EaFut..1103187G |doi=10.1029/2022EF003187 |s2cid=256227421|doi-access=free }}</ref> | |||
== By region == | |||
=== Africa === | |||
{{Further|Climate change in the Middle East and North Africa#Sea level rise}} | |||
], a suburb of ]. Sunny day flooding caused by sea level rise, increases ] that destroys housing, infrastructure and natural ecosystems. A number of communities in Coastal Ghana are already experiencing the changing tides.]] | |||
In ], future ] amplifies risks from sea level rise. Some 54.2 million people lived in the highly exposed low elevation coastal zones (LECZ) around 2000. This number will effectively double to around 110 million people by 2030, and then reach 185 to 230 million people by 2060. By then, the average regional sea level rise will be around 21 cm, with little difference from climate change scenarios.<ref name="AR6_WGII_Chapter9" /> By 2100, ], ] and ] are likely to have the largest number of people affected by annual flooding amongst all African countries. And under RCP8.5, 10 important cultural sites would be at risk of flooding and erosion by the end of the century.<ref name="AR6_WGII_Chapter9" /> | |||
In the near term, some of the largest displacement is projected to occur in the ] region. At least 750,000 people there are likely to be displaced from the coasts between 2020 and 2050. By 2050, 12 major African cities would collectively sustain cumulative damages of US$65 billion for the "moderate" climate change scenario RCP4.5 and between US$86.5 billion to US$137.5 billion on average: in the worst case, these damages could effectively triple.<ref name="AR6_WGII_Chapter9" /> In all of these estimates, around half of the damages would occur in the Egyptian city of Alexandria.<ref name="AR6_WGII_Chapter9" /> Hundreds of thousands of people in its low-lying areas may already need relocation in the coming decade.<ref name="Michaelson-2018">{{cite news|url=https://www.theguardian.com/global-development/2018/aug/29/alexandria-little-venice-egypt-climate-change-frontline|title=Houses claimed by the canal: life on Egypt's climate change frontline|last=Michaelson|first=Ruth|date=25 August 2018|work=]|access-date=30 August 2018|archive-date=1 August 2020|archive-url=https://web.archive.org/web/20200801005257/https://www.theguardian.com/global-development/2018/aug/29/alexandria-little-venice-egypt-climate-change-frontline|url-status=live}}</ref> Across ] as a whole, damage from sea level rise could reach 2–4% of ] by 2050, although this depends on the extent of future ] and ].<ref name="AR6_WGII_Chapter9" /> | |||
=== Asia === | |||
{{Further|Climate change in Asia#Sea level rise}} | |||
], located in ] of Honshu Island]] | |||
] | |||
Asia has the largest population at risk from sea level due to its dense coastal populations. As of 2022, some 63 million people in ] and ] were already at risk from a ]. This is largely due to inadequate coastal protection in many countries. ], ], ], ], ], ], the ], ] and ] alone account for 70% of people exposed to sea level rise during the 21st century.<ref name="AR6_WGII_Chapter10" /><ref>{{Cite journal|last=McLeman|first=Robert|date=2018|title=Migration and displacement risks due to mean sea-level rise|journal=Bulletin of the Atomic Scientists|volume=74|issue=3|pages=148–154|doi=10.1080/00963402.2018.1461951|issn=0096-3402|bibcode=2018BuAtS..74c.148M|s2cid=150179939}}</ref> ] is likely to displace 0.9-2.1 million people by 2050. It may also force the relocation of up to one third of power plants as early as 2030, and many of the remaining plants would have to deal with the increased salinity of their cooling water.<ref name="AR6_WGII_Chapter10" /><ref name="DeLellis2021">{{cite journal |last1=De Lellis |first1=Pietro |last2=Marín |first2=Manuel Ruiz |last3=Porfiri |first3=Maurizio |date=29 March 2021 |title=Modeling Human Migration Under Environmental Change: A Case Study of the Effect of Sea Level Rise in Bangladesh |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020EF001931 |journal=Earth's Future |volume=9 |issue=4 |pages=e2020EF001931 |doi=10.1029/2020EF001931 |bibcode=2021EaFut...901931D |hdl=10317/13078 |s2cid=233626963 |access-date=27 October 2022 |archive-date=27 October 2022 |archive-url=https://web.archive.org/web/20221027180934/https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020EF001931 |url-status=live }}</ref> Nations like Bangladesh, Vietnam and China with extensive rice production on the coast are already seeing adverse impacts from saltwater intrusion.<ref>{{Cite web|url=http://www.fao.org/nr/climpag/pub/EIre0047_en.asp|title=Potential Impacts of Sea-Level Rise on Populations and Agriculture|website=www.fao.org|access-date=2018-10-21|archive-date=2020-04-18|archive-url=https://web.archive.org/web/20200418035608/http://www.fao.org/nr/climpag/pub/eire0047_en.asp}}</ref> | |||
Modelling results predict that Asia will suffer direct economic damages of US$167.6 billion at 0.47 meters of sea level rise. This rises to US$272.3 billion at 1.12 meters and US$338.1 billion at 1.75 meters. There is an additional indirect impact of US$8.5, 24 or 15 billion from population displacement at those levels. China, India, the ], Japan, Indonesia and ] experience the largest economic losses.<ref name="AR6_WGII_Chapter10">Shaw, R., Y. Luo, T. S. Cheong, S. Abdul Halim, S. Chaturvedi, M. Hashizume, G. E. Insarov, Y. Ishikawa, M. Jafari, A. Kitoh, J. Pulhin, C. Singh, K. Vasant, and Z. Zhang, 2022: {{Webarchive|url=https://web.archive.org/web/20230412072953/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter10.pdf |date=2023-04-12 }}. In {{Webarchive|url=https://web.archive.org/web/20220228114918/https://www.ipcc.ch/report/ar6/wg2/ |date=2022-02-28 }} . Cambridge University Press, Cambridge, UK and New York, US, pp. 1457–1579. {{doi|10.1017/9781009325844.012}}.</ref> Out of the 20 coastal cities expected to see the highest flood losses by 2050, 13 are in Asia. Nine of these are the so-called ], where ] (typically caused by unsustainable ] extraction in the past) would compound sea level rise. These are ], ], ], ], ], ], ], ] and ].<ref>{{Cite journal|last1=Erkens|first1=G.|last2=Bucx|first2=T.|last3=Dam|first3=R.|last4=de Lange|first4=G.|last5=Lambert|first5=J.|date=2015-11-12|title=Sinking coastal cities|url=https://piahs.copernicus.org/articles/372/189/2015/|journal=Proceedings of the International Association of Hydrological Sciences|language=en|volume=372|pages=189–198|doi=10.5194/piahs-372-189-2015|bibcode=2015PIAHS.372..189E|issn=2199-899X|doi-access=free|access-date=2021-02-03|archive-date=2023-03-11|archive-url=https://web.archive.org/web/20230311121820/https://piahs.copernicus.org/articles/372/189/2015/|url-status=live}}</ref> | |||
By 2050, Guangzhou would see 0.2 meters of sea level rise and estimated ''annual'' economic losses of US$254 million – the highest in the world.<ref name="AR6_WGII_Chapter10" /> In ], coastal inundation amounts to about 0.03% of local ], yet would increase to 0.8% by 2100 even under the "moderate" ] scenario in the absence of adaptation.<ref name="AR6_WGII_Chapter10" /> The city of ] is ] so much (up to {{cvt|28|cm|in|frac=2}} per year between 1982 and 2010 in some areas<ref>{{cite journal |last1=Abidin |first1=Hasanuddin Z. |last2=Andreas |first2=Heri |last3=Gumilar |first3=Irwan |last4=Fukuda |first4=Yoichi |last5=Pohan |first5=Yusuf E. |last6=Deguchi |first6=T. |title=Land subsidence of Jakarta (Indonesia) and its relation with urban development |journal=Natural Hazards |date=11 June 2011 |volume=59 |issue=3 |pages=1753–1771 |doi=10.1007/s11069-011-9866-9 |bibcode=2011NatHa..59.1753A |s2cid=129557182}}</ref>) that in 2019, the government had committed to relocate the ] to another city.<ref>{{Cite news|url=https://www.washingtonpost.com/opinions/2019/05/03/seas-rise-indonesia-is-moving-its-capital-city-other-cities-should-take-note/|title=As seas rise, Indonesia is moving its capital city. Other cities should take note.|last=Englander|first=John|date=3 May 2019|newspaper=]|access-date=31 August 2019|archive-date=13 May 2020|archive-url=https://web.archive.org/web/20200513144058/https://www.washingtonpost.com/opinions/2019/05/03/seas-rise-indonesia-is-moving-its-capital-city-other-cities-should-take-note/|url-status=live}}</ref> | |||
=== Australasia === | |||
]]] | |||
In ], erosion and flooding of ]'s ] beaches is likely to intensify by 60% by 2030. Without adaptation there would be a big impact on tourism. Adaptation costs for sea level rise would be three times higher under the high-emission ]8.5 scenario than in the low-emission RCP2.6 scenario. Sea level rise of 0.2-0.3 meters is likely by 2050. In these conditions what is currently a ] would occur every year in the ] cities of ] and ]. With 0.5 m sea level rise, a current 100-year flood in Australia would occur several times a year. In New Zealand this would expose buildings with a collective worth of NZ$12.75 billion to new 100-year floods. A meter or so of sea level rise would threaten assets in New Zealand with a worth of NZD$25.5 billion. There would be a disproportionate impact on ]-owned holdings and cultural heritage objects. Australian assets worth AUS$164–226 billion including many ]s and ]s would also be at risk. This amounts to a 111% rise in Australia's inundation costs between 2020 and 2100.<ref name="AR6_WGII_Chapter11">Lawrence, J., B. Mackey, F. Chiew, M.J. Costello, K. Hennessy, N. Lansbury, U.B. Nidumolu, G. Pecl, L. Rickards, N. Tapper, | |||
A. Woodward, and A. Wreford, 2022: {{Webarchive|url=https://web.archive.org/web/20230314233029/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter11.pdf |date=2023-03-14 }}. In {{Webarchive|url=https://web.archive.org/web/20220228114918/https://www.ipcc.ch/report/ar6/wg2/ |date=2022-02-28 }} . Cambridge University Press, Cambridge, UK and New York, US, pp. 1581–1688, | |||
|doi=10.1017/9781009325844.013</ref> | |||
=== Central and South America === | |||
]'s Port of Santos]] | |||
By 2100, coastal flooding and erosion will affect at least 3-4 million people in ]. Many people live in low-lying areas exposed to sea level rise. This includes 6% of the population of ], 56% of the population of ] and 68% of the population of ]. In Guyana much of the capital ] is already below sea level. In ], the coastal ecoregion of ] is responsible for 99% of its ] production. A combination of sea level rise, ocean warming and ] threaten its unique ecosystem. Extreme wave or wind behavior disrupted the port complex of ] 76 times in one 6-year period in the 2010s. There was a US$25,000-50,000 loss for each idle day. In ], ]s were three times more frequent between 2000 and 2016 than between 1928 and 1999.<ref name="AR6_WGII_Chapter12">Castellanos, E., M.F. Lemos, L. Astigarraga, N. Chacón, N. Cuvi, C. Huggel, L. Miranda, M. Moncassim Vale, J.P. Ometto, | |||
P.L. Peri, J.C. Postigo, L. Ramajo, L. Roco, and M. Rusticucci, 2022: {{Webarchive|url=https://web.archive.org/web/20230320192415/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter12.pdf |date=2023-03-20 }}. In {{Webarchive|url=https://web.archive.org/web/20220228114918/https://www.ipcc.ch/report/ar6/wg2/ |date=2022-02-28 }} . Cambridge University Press, Cambridge, UK and New York, US, pp. 1689–1816 {{doi|10.1017/9781009325844.014}}</ref> | |||
=== Europe === | |||
] in progress in ].]] | |||
Many sandy coastlines in ] are vulnerable to erosion due to sea level rise. In ], ] is likely to retreat by 16 meters by 2050 relative to 2010. This could amount to 52 meters by 2100 under RCP8.5<ref>{{cite journal |last1=Ballesteros |first1=Caridad |last2=Jiménez |first2=José A. |last3=Valdemoro |first3=Herminia I. |last4=Bosom |first4=Eva |date=7 September 2017 |title=Erosion consequences on beach functions along the Maresme coast (NW Mediterranean, Spain) |journal=Natural Hazards |language=en |volume=90 |pages=173–195 |doi=10.1007/s11069-017-3038-5 |s2cid=135328414 |doi-access=free |hdl=2117/114541 |hdl-access=free }}</ref> Other vulnerable coastlines include the ] coast of ]'s ] region,<ref>{{cite journal |last1=Ietto |first1=Fabio |last2=Cantasano |first2=Nicola |last3=Pellicone |first3=Gaetano |date=11 April 2018 |title=A New Coastal Erosion Risk Assessment Indicator: Application to the Calabria Tyrrhenian Littoral (Southern Italy) |url=https://link.springer.com/article/10.1007/s40710-018-0295-6 |journal=Environmental Processes |language=en |volume=5 |issue=2 |pages=201–223 |doi=10.1007/s40710-018-0295-6 |bibcode=2018EProc...5..201I |s2cid=134889581 |access-date=17 April 2023 |archive-date=22 April 2023 |archive-url=https://web.archive.org/web/20230422111655/https://link.springer.com/article/10.1007/s40710-018-0295-6 |url-status=live }}</ref> the Barra-Vagueira coast in ]<ref>{{cite journal |last1=Ferreira |first1=A. M. |last2=Coelho |first2=C. |last3=Narra |first3=P. |date=13 October 2020 |title=Coastal erosion risk assessment to discuss mitigation strategies: Barra-Vagueira, Portugal |url=https://link.springer.com/article/10.1007/s11069-020-04349-2 |journal=Natural Hazards |language=en |volume=105 |pages=1069–1107 |doi=10.1007/s11069-020-04349-2 |s2cid=222318289 |access-date=17 April 2023 |archive-date=21 April 2023 |archive-url=https://web.archive.org/web/20230421025813/https://link.springer.com/article/10.1007/s11069-020-04349-2 |url-status=live }}</ref> and Nørlev Strand in ].<ref>{{cite journal |last1=Rivero |first1=Ofelia Yocasta |last2=Margheritini |first2=Lucia |last3=Frigaard |first3=Peter |date=4 February 2021 |title=Accumulated effects of chronic, acute and man-induced erosion in Nørlev strand on the Danish west coast |journal=Journal of Coastal Conservation |language=en |volume=25 |issue=1 |page=24 |doi=10.1007/s11852-021-00812-9 |bibcode=2021JCC....25...24R |s2cid=231794192 |doi-access=free }}</ref> | |||
In France, it was estimated that 8,000-10,000 people would be forced to migrate away from the coasts by 2080.<ref>{{Cite journal|last1=Tierolf|first1=Lars|last2=Haer|first2=Toon Haer|last3=Wouter Botzen|first3=W. J.|last4=de Bruijn|first4=Jens A. |last5=Ton |first5=Marijn J. |last6=Reimann|first6=Lena|last7=Aerts |first7=Jeroen C. J. H. |date=13 March 2023|title=A coupled agent-based model for France for simulating adaptation and migration decisions under future coastal flood risk|journal=Scientific Reports|volume=13 |issue=1 |page=4176 |doi=10.1038/s41598-023-31351-y |pmid=36914726 |pmc=10011601 |bibcode=2023NatSR..13.4176T}}</ref> The Italian city of ] is located on islands. It is highly ] and has already spent $6 billion on a barrier system.<ref>{{cite news |last1=Calma |first1=Justine |title=Venice's historic flooding blamed on human failure and climate change |url=https://www.theverge.com/2019/11/14/20963878/venice-high-tide-climate-change-flood-barrier-sea-levels |access-date=17 November 2019 |agency=The Verge |date=November 14, 2019 |archive-date=1 August 2020 |archive-url=https://web.archive.org/web/20200801002415/https://www.theverge.com/2019/11/14/20963878/venice-high-tide-climate-change-flood-barrier-sea-levels |url-status=live }}</ref><ref>{{cite news |last1=Shepherd |first1=Marshall |title=Venice Flooding Reveals A Real Hoax About Climate Change - Framing It As "Either/Or" |url=https://www.forbes.com/sites/marshallshepherd/2019/11/16/venice-flooding-reveals-a-real-hoax-about-climate-changeframing-it-as-eitheror/ |access-date=17 November 2019 |agency=Forbes |date=16 November 2019 |archive-date=2 May 2020 |archive-url=https://web.archive.org/web/20200502135528/https://www.forbes.com/sites/marshallshepherd/2019/11/16/venice-flooding-reveals-a-real-hoax-about-climate-changeframing-it-as-eitheror/ |url-status=live }}</ref> A quarter of the German state of ], inhabited by over 350,000 people, is at low elevation and has been vulnerable to flooding since preindustrial times. Many ]s already exist. Because of its complex geography, the authorities chose a flexible mix of hard and soft measures to cope with sea level rise of over 1 meter per century.<ref name="Hurk2022">{{Cite journal|last1=van der Hurk|first1=Bart|last2=Bisaro|first2=Alexander|last3=Haasnoot|first3=Marjolijn|last4=Nicholls|first4=Robert J. |last5=Rehdanz |first5=Katrin |last6=Stuparu|first6=Dana|date=28 January 2022|title=Living with sea-level rise in North-West Europe: Science-policy challenges across scales|journal=Climate Risk Management|volume=35|page=100403 |doi=10.1016/j.crm.2022.100403 |bibcode=2022CliRM..3500403V |s2cid=246354121}}</ref> In the ], sea level at the end of the century would increase by 53 to 115 centimeters at the mouth of the River ] and 30 to 90 centimeters at ].<ref>{{cite journal |last1=Howard |first1=Tom |last2=Palmer |first2=Matthew D |last3=Bricheno |first3=Lucy M |date=18 September 2019 |title=Contributions to 21st century projections of extreme sea-level change around the UK |url=https://iopscience.iop.org/article/10.1088/2515-7620/ab42d7 |journal=Environmental Research Communications |language=en |volume=1 |issue=9 |page=095002 |doi=10.1088/2515-7620/ab42d7 |bibcode=2019ERCom...1i5002H |s2cid=203120550 |access-date=17 April 2023 |archive-date=21 April 2023 |archive-url=https://web.archive.org/web/20230421170159/https://iopscience.iop.org/article/10.1088/2515-7620/ab42d7 |url-status=live }}</ref> The UK has divided its coast into 22 areas, each covered by a Shoreline Management Plan. Those are sub-divided into 2000 management units, working across three periods of 0–20, 20-50 and 50–100 years.<ref name="Hurk2022" /> | |||
The ] is a country that sits partially below sea level and is subsiding. It has responded by extending its ] program.<ref>{{Cite news|url=https://www.nytimes.com/interactive/2017/06/15/world/europe/climate-change-rotterdam.html,%20https://www.nytimes.com/interactive/2017/06/15/world/europe/climate-change-rotterdam.html|title=The Dutch Have Solutions to Rising Seas. The World Is Watching.|last1=Kimmelman|first1=Michael|date=2017-06-15|work=The New York Times|access-date=2019-02-02|last2=Haner|first2=Josh|issn=0362-4331}}</ref> Drafted in 2008, the ''Delta Commission'' report said that the country must plan for a rise in the ] up to {{convert|1.3|m|ftin|abbr=on}} by 2100 and plan for a {{convert|2 - 4|m|ft|0|sigfig=1|abbr=on}} rise by 2200.<ref>{{Cite news|url=https://www.nytimes.com/2008/09/03/news/03iht-03dutch.15877468.html|title=Dutch draw up drastic measures to defend coast against rising seas|date=3 September 2008|work=]|access-date=25 February 2017|archive-date=21 August 2017|archive-url=https://web.archive.org/web/20170821050301/http://www.nytimes.com/2008/09/03/news/03iht-03dutch.15877468.html|url-status=live}}</ref> It advised annual spending between €1.0 and €1.5 billion. This would support measures such as broadening coastal ] and strengthening sea and river ]. Worst-case evacuation plans were also drawn up.<ref>{{cite news |title=Rising Sea Levels Threaten Netherlands |url=https://www.newspapers.com/image/514725270/ |access-date=28 October 2022 |work=National Post |agency=Agence France-Presse |date=September 4, 2008 |location=Toronto |page=AL12 |archive-date=28 October 2022 |archive-url=https://web.archive.org/web/20221028180908/https://www.newspapers.com/image/514725270/ |url-status=live }}</ref> | |||
=== North America === | |||
] in ] during a ] (October 17, 2016). The risk of tidal flooding increases with sea level rise.]] | |||
As of 2017, around 95 million Americans lived on the coast. The figures for ] and ] were 6.5 million and 19 million. Increased chronic ] and ] flooding is already a problem in the highly ] state of ].<ref>{{Cite web|date=2020-02-10|title=Florida Coastal Flooding Maps: Residents Deny Predicted Risks to Their Property|url=https://www.ecowatch.com/florida-coastal-flooding-maps-2645087745.html|access-date=2021-01-31|website=EcoWatch|language=en|archive-date=2023-06-04|archive-url=https://web.archive.org/web/20230604152002/https://www.ecowatch.com/florida-coastal-flooding-maps-2645087745.html|url-status=live}}</ref> The ] is also vulnerable.<ref>{{cite journal|last1=Sweet & Park |title=Increased nuisance flooding along the coasts of the United States due to sea level rise: Past and future |journal=Geophysical Research Letters |year=2015 |volume=42 |issue=22 |pages=9846–9852 |doi=10.1002/2015GL066072 |bibcode=2015GeoRL..42.9846M |s2cid=19624347}}</ref> On average, the number of days with ] in the US increased 2 times in the years 2000–2020, reaching 3–7 days per year. In some areas the increase was much stronger: 4 times in the Southeast Atlantic and 11 times in the Western Gulf. By the year 2030 the average number is expected to be 7–15 days, reaching 25–75 days by 2050.<ref>{{cite web |title=High Tide Flooding |url=https://coast.noaa.gov/states/fast-facts/recurrent-tidal-flooding.html |website=NOAA |access-date=10 July 2023 |archive-date=19 August 2023 |archive-url=https://web.archive.org/web/20230819201149/https://coast.noaa.gov/states/fast-facts/recurrent-tidal-flooding.html |url-status=live }}</ref> U.S. coastal cities have responded with ] or ''beach replenishment.'' This trucks in mined sand in addition to other adaptation measures such as zoning, restrictions on state funding, and building code standards.<ref name="ClimateCentral2012">{{cite web|url=http://www.climatecentral.org/news/its-beach-season-enjoy-it-while-you-can|title=Climate Change, Sea Level Rise Spurring Beach Erosion|year=2012|website=Climate Central|access-date=2018-08-20|archive-date=2020-08-06|archive-url=https://web.archive.org/web/20200806010206/https://www.climatecentral.org/news/its-beach-season-enjoy-it-while-you-can|url-status=live}}</ref><ref>{{Cite journal|last=Carpenter|first=Adam T.|date=2020-05-04|title=Public priorities on locally-driven sea level rise planning on the East Coast of the United States|journal=PeerJ|language=en|volume=8|pages=e9044|doi=10.7717/peerj.9044|pmid=32411525|pmc=7204830|issn=2167-8359 |doi-access=free}}</ref> | |||
Along an estimated ~15% of the US coastline, the majority of local ] levels are already below sea level. This places those groundwater reservoirs at risk of sea water intrusion. That would render fresh water unusable once its concentration exceeds 2-3%.<ref>{{cite journal |last1=Jasechko |first1=Scott J.|last2=Perrone |first2=Debra |last3=Seybold |first3=Hansjörg |last4=Fan |first4=Ying |last5=Kirchner |first5=James W. |title=Groundwater level observations in 250,000 coastal US wells reveal scope of potential seawater intrusion |date=26 June 2020 |journal=Nature Communications |volume=11 |issue=1 |page=3229 |doi=10.1038/s41467-020-17038-2 |pmid=32591535 |pmc=7319989 |bibcode=2020NatCo..11.3229J}}</ref> Damage is also widespread in Canada. It will affect major cities like ] and more remote locations like ]. The ] ] there is already considering relocation due to widespread coastal erosion. In Mexico, damage from SLR to ] hotspots like ], ], ], ] and ] could amount to US$1.4–2.3 billion.<ref name="AR6_WGII_Chapter14" /> The increase in ] due to sea level rise is also a problem. Due to this effect ] caused an additional US$8 billion in damage, impacted 36,000 more houses and 71,000 more people.<ref>{{cite journal |title=Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change |journal=Nature Communications |date=18 May 2021 |volume=12 |bibcode=2021NatCo..12.2720S |last1=Strauss |first1=Benjamin H. |last2=Orton |first2=Philip M. |last3=Bittermann |first3=Klaus |last4=Buchanan |first4=Maya K. |last5=Gilford |first5=Daniel M. |last6=Kopp |first6=Robert E. |last7=Kulp |first7=Scott |last8=Massey |first8=Chris |last9=Moel |first9=Hans de |last10=Vinogradov |first10=Sergey |issue=1 |page=2720 |doi=10.1038/s41467-021-22838-1 |pmid=34006886 |pmc=8131618 |s2cid=234783225}}</ref><ref>{{cite news |last1=Seabrook |first1=Victoria |title=Climate change to blame for $8 billion of Hurricane Sandy losses, study finds |url=https://news.sky.com/story/climate-change-to-blame-for-8-billion-of-hurricane-sandy-losses-study-finds-12309974#:~:text=The%20raised%20water%20levels%20allowed,36%2C000%20homes%20and%2071%2C000%20people. |access-date=9 July 2023 |agency=Sky News |publisher=Nature Communications |date=19 May 2021 |archive-date=9 July 2023 |archive-url=https://web.archive.org/web/20230709130045/https://news.sky.com/story/climate-change-to-blame-for-8-billion-of-hurricane-sandy-losses-study-finds-12309974#:~:text=The%20raised%20water%20levels%20allowed,36%2C000%20homes%20and%2071%2C000%20people. |url-status=live }}</ref> In the future, the northern ], ] and the ] would experience the greatest sea level rise. By 2030, flooding along the US ] could cause economic losses of up to US$176 billion. Using ] like ] and ] restoration could avoid around US$50 billion of this.<ref name="AR6_WGII_Chapter14" /> | |||
] predicts different levels of sea level rise through 2050 for several US coastlines.<ref name=NOAA-2022 />|alt=A comparison of SLR in six parts of the US. The Gulf Coast and East Coast see the most SLR, whereas the West Coast the least]] | |||
By 2050, coastal flooding in the US is likely to rise tenfold to four "moderate" flooding events per year. That forecast is even without storms or heavy rainfall.<ref>{{cite web |title=U.S Coastline to See Up to a Foot of Sea Level by 2050 |url=https://www.noaa.gov/news-release/us-coastline-to-see-up-to-foot-of-sea-level-rise-by-2050 |access-date=February 16, 2022 |website=National Oceanic and Atmospheric Administration |date=15 February 2022 |archive-date=5 July 2023 |archive-url=https://web.archive.org/web/20230705195211/https://www.noaa.gov/news-release/us-coastline-to-see-up-to-foot-of-sea-level-rise-by-2050 |url-status=live }}</ref><ref>{{cite web |date=2022 |title=More Damaging Flooding, 2022 Sea Level Rise Technical Report |url=https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html#step2 |access-date=2022-03-18 |website=National Ocean Service, ] |archive-date=2022-11-29 |archive-url=https://web.archive.org/web/20221129070303/https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html#step2 |url-status=live }}</ref> In ], current ] would occur once in 19–68 years by 2050 and 4–60 years by 2080.<ref>{{cite web|last=Gornitz|first=Vivien|date=2002|title=Impact of Sea Level Rise in the New York City Metropolitan Area|url=https://eportfolios.macaulay.cuny.edu/bird2012/files/2012/07/Impacts-of-SLR-in-the-NYC-Metropolitan-Area.-pdf.pdf|access-date=2020-08-09|website=Global and Planetary Change|archive-date=2019-09-26|archive-url=https://web.archive.org/web/20190926115312/https://eportfolios.macaulay.cuny.edu/bird2012/files/2012/07/Impacts-of-SLR-in-the-NYC-Metropolitan-Area.-pdf.pdf|url-status=dead}}</ref> By 2050, 20 million people in the greater ] area would be at risk. This is because 40% of existing ] facilities would be compromised and 60% of ]s will need relocation. | |||
By 2100, sea level rise of {{cvt|0.9|m|ft|frac=2}} and {{cvt|1.8|m|ft|frac=2}} would threaten 4.2 and 13.1 million people in the US, respectively. In ] alone, {{cvt|2|m|ft|frac=2}} of SLR could affect 600,000 people and threaten over US$150 billion in property with inundation. This potentially represents over 6% of the state's ]. In ], a meter of SLR inundates 42% of the ], costing up to US$14 billion. In nine southeast US states, the same level of sea level rise would claim up to 13,000 historical and archaeological sites, including over 1000 sites eligible for inclusion in the ].<ref name="AR6_WGII_Chapter14">Hicke, J.A., S. Lucatello, L.D., Mortsch, J. Dawson, M. Domínguez Aguilar, C.A.F. Enquist, E.A. Gilmore, D.S. Gutzler, S. Harper, K. Holsman, E.B. Jewett, T.A. Kohler, and KA. Miller, 2022: {{Webarchive|url=https://web.archive.org/web/20230320192436/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter14.pdf |date=2023-03-20 }}. In {{Webarchive|url=https://web.archive.org/web/20220228114918/https://www.ipcc.ch/report/ar6/wg2/ |date=2022-02-28 }} . Cambridge University Press, Cambridge, UK and New York, US, pp. 1929–2042</ref> | |||
=== Island nations === | |||
], the capital island of ].]] | |||
{{Further|Effects of climate change on island nations|Small Island Developing States|Alliance of Small Island States}} | |||
Small island states are nations with populations on ]s and other ]s. Atolls on average reach {{convert|3-6|ft|m|1|order=flip|abbr=on}} above sea level.<ref>{{Cite web|title=Many Low-Lying Atoll Islands Will Be Uninhabitable by Mid-21st Century {{!}} U.S. Geological Survey|url=https://www.usgs.gov/news/national-news-release/many-low-lying-atoll-islands-will-be-uninhabitable-mid-21st-century|access-date=2021-12-17|website=www.usgs.gov|archive-date=2023-06-06|archive-url=https://web.archive.org/web/20230606155303/https://www.usgs.gov/news/national-news-release/many-low-lying-atoll-islands-will-be-uninhabitable-mid-21st-century|url-status=live}}</ref> These are the most vulnerable places to ], flooding and salt intrusion ] and freshwater caused by sea level rise. Sea level rise may make an island uninhabitable before it is completely flooded.<ref>{{Cite journal|last1=Zhu|first1=Bozhong|last2=Bai|first2=Yan|last3=He|first3=Xianqiang|last4=Chen|first4=Xiaoyan|last5=Li|first5=Teng|last6=Gong|first6=Fang|date=2021-09-18|title=Long-Term Changes in the Land–Ocean Ecological Environment in Small Island Countries in the South Pacific: A Fiji Vision|journal=Remote Sensing|language=en|volume=13|issue=18|page=3740|doi=10.3390/rs13183740|bibcode=2021RemS...13.3740Z|issn=2072-4292|doi-access=free}}</ref> Already, children in small island states encounter hampered access to food and water. They suffer an increased rate of mental and social disorders due to these stresses.<ref>{{Cite journal|last1=Sly|first1=Peter D|last2=Vilcins|first2=Dwan|date=November 2021|title=Climate impacts on air quality and child health and wellbeing: Implications for Oceania|url=https://onlinelibrary.wiley.com/doi/10.1111/jpc.15650|journal=Journal of Paediatrics and Child Health|language=en|volume=57|issue=11|pages=1805–1810|doi=10.1111/jpc.15650|pmid=34792251|s2cid=244271480|issn=1034-4810|access-date=2021-12-17|archive-date=2023-01-23|archive-url=https://web.archive.org/web/20230123144925/https://onlinelibrary.wiley.com/doi/10.1111/jpc.15650|url-status=live}}</ref> At current rates, sea level rise would be high enough to make the Maldives uninhabitable by 2100.<ref>{{cite web |author=Megan Angelo |date=1 May 2009 |title=Honey, I Sunk the Maldives: Environmental changes could wipe out some of the world's most well-known travel destinations |url=http://travel.yahoo.com/p-interests-27384279;_ylc=X3oDMTFxcWIyczFpBF9TAzI3MTYxNDkEX3MDMjcxOTQ4MQRzZWMDZnAtdG9kYXltb2QEc2xrA21hbGRpdmVzLTQtMjgtMDk- |archive-url=https://web.archive.org/web/20120717041919/http://travel.yahoo.com/p-interests-27384279 |archive-date=17 July 2012 |access-date=29 September 2009}}</ref><ref>{{cite web |author=Kristina Stefanova |date=19 April 2009 |title=Climate refugees in Pacific flee rising sea |url=http://www.washingtontimes.com/news/2009/apr/19/rising-sea-levels-in-pacific-create-wave-of-migran/ |website=] |access-date=29 September 2009 |archive-date=18 October 2017 |archive-url=https://web.archive.org/web/20171018075225/http://www.washingtontimes.com/news/2009/apr/19/rising-sea-levels-in-pacific-create-wave-of-migran/ |url-status=live }}</ref> Five of the ] have already disappeared due to the effects of sea level rise and stronger trade winds pushing water into the ].<ref>{{Cite web |last=Klein |first=Alice |title=Five Pacific islands vanish from sight as sea levels rise |url=https://www.newscientist.com/article/2087356-five-pacific-islands-vanish-from-sight-as-sea-levels-rise/ |access-date=2016-05-09 |website=New Scientist |archive-date=2020-03-31 |archive-url=https://web.archive.org/web/20200331123810/https://www.newscientist.com/article/2087356-five-pacific-islands-vanish-from-sight-as-sea-levels-rise/ |url-status=live }}</ref> | |||
] and ]<ref name="Albeert2016">{{Cite Q|Q29028186}}</ref>]] | |||
Adaptation to sea level rise is costly for small island nations as a large portion of their population lives in areas that are at risk.<ref>{{Cite book|chapter-url=http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap29_FINAL.pdf|title=AR5 WGII|last1=Nurse|first1=Leonard A.|last2=McLean|first2=Roger|publisher=Cambridge University Press|year=2014|editor-last=Barros|editor-first=VR|chapter=29: Small Islands|editor-last2=Field|access-date=2018-09-02|archive-date=2018-04-30|archive-url=https://web.archive.org/web/20180430194832/http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap29_FINAL.pdf}}</ref> Nations like ], ] and ] already have to consider controlled international migration of their population in response to rising seas.<ref name="Grecequet2017" /> The alternative of uncontrolled migration threatens to worsen the humanitarian crisis of ].<ref>{{Cite web|last=Nations|first=United|title=Small Islands, Rising Seas|url=https://www.un.org/en/chronicle/article/small-islands-rising-seas|access-date=2021-12-17|website=United Nations|language=en|archive-date=2023-05-06|archive-url=https://web.archive.org/web/20230506043040/https://www.un.org/en/chronicle/article/small-islands-rising-seas|url-status=live}}</ref> In 2014, Kiribati purchased 20 square kilometers of land (about 2.5% of Kiribati's current area) on the ]an island of ] to relocate its population once their own islands are lost to the sea.<ref>{{cite news|url=https://www.theguardian.com/environment/2014/jul/01/kiribati-climate-change-fiji-vanua-levu|title=Besieged by the rising tides of climate change, Kiribati buys land in Fiji|last1=Caramel|first1=Laurence|date=July 1, 2014|access-date=9 January 2023|agency=The Guardian|archive-date=13 November 2022|archive-url=https://web.archive.org/web/20221113085156/https://www.theguardian.com/environment/2014/jul/01/kiribati-climate-change-fiji-vanua-levu|url-status=live}}</ref> | |||
] also suffers from sea level rise.<ref>{{Cite journal |last=Long |first=Maebh |author-link=Maebh Long |year=2018 |title=Vanua in the Anthropocene: Relationality and Sea Level Rise in Fiji |url=https://muse.jhu.edu/article/710005 |journal=Symplokē |volume=26 |issue=1–2 |pages=51–70 |doi=10.5250/symploke.26.1-2.0051 |s2cid=150286287 |access-date=2019-10-04 |archive-date=2019-07-28 |archive-url=https://web.archive.org/web/20190728152330/https://muse.jhu.edu/article/710005 |url-status=live }}</ref> It is in a comparatively safer position. Its residents continue to rely on local adaptation like moving further inland and increasing ] supply to combat erosion instead of relocating entirely.<ref name="Grecequet2017">{{Cite web|url=http://theconversation.com/many-small-island-nations-can-adapt-to-climate-change-with-global-support-86820|title=Many small island nations can adapt to climate change with global support|last1=Grecequet|first1=Martina|last2=Noble|first2=Ian|date=2017-11-16|website=The Conversation|access-date=2019-02-02|last3=Hellmann|first3=Jessica|archive-date=2020-05-27|archive-url=https://web.archive.org/web/20200527091318/https://theconversation.com/many-small-island-nations-can-adapt-to-climate-change-with-global-support-86820|url-status=live}}</ref> Fiji has also issued a green bond of $50 million to invest in green initiatives and fund adaptation efforts. It is restoring ]s and ]s to protect against flooding and erosion. It sees this as a more cost-efficient alternative to building ]s. The nations of ] and ] are taking similar steps.<ref name="Grecequet2017" /><ref>{{Cite web|url=http://www.unenvironment.org/news-and-stories/video/adaptation-sea-level-rise|title=Adaptation to Sea Level Rise|date=2018-01-11|website=UN Environment|access-date=2019-02-02|archive-date=2020-08-07|archive-url=https://web.archive.org/web/20200807072424/https://www.unenvironment.org/news-and-stories/video/adaptation-sea-level-rise|url-status=live}}</ref> Even when an island is not threatened with complete disappearance from flooding, tourism and local economies may end up devastated. For instance, sea level rise of {{cvt|1.0|m|ftin|0}} would cause partial or complete inundation of 29% of coastal resorts in the ]. A further 49–60% of coastal resorts would be at risk from resulting coastal erosion.<ref>{{Cite journal|last1=Thomas|first1=Adelle|last2=Baptiste|first2=April|last3=Martyr-Koller|first3=Rosanne|last4=Pringle|first4=Patrick|last5=Rhiney|first5=Kevon|date=2020-10-17|title=Climate Change and Small Island Developing States|journal=Annual Review of Environment and Resources|language=en|volume=45|issue=1|pages=1–27|doi=10.1146/annurev-environ-012320-083355|issn=1543-5938|doi-access=free}}</ref> | |||
== See also == | |||
* {{annotated link|Climate emergency declaration}} | |||
* {{annotated link|Coastal development hazards}} | |||
* {{annotated link|Effects of climate change on oceans}} | |||
* {{annotated link|List of countries by average elevation}} | |||
* {{annotated link|Paleoclimate}} | |||
== References == | |||
{{Reflist|24em}} | |||
== External links == | == External links == | ||
{{Wikibooks|Historical Geology|Sea level variations}} | |||
* {{Web reference | title=Sea Level Changes in the Past, Present and in the Near-Future Global Aspects Observations versus Modells | work=IGCP Project No. 437 Puglia 2003 - Final Conference | URL=http://www.dsm.unile.it/Bacheca/IGCP437FinalConference/AbstractBook/Morner5_10.pdf | date=10 February | year=2005}} | |||
{{Portal|Oceans|Climate change|Energy|Renewable energy|Environment}} | |||
* {{Web reference | title=Sea Level Changes: The Maldives Project Freed From Condemnation to become Flooded | work=IGCP Project No. 437 Puglia 2003 - Final Conference | URL=http://www.dsm.unile.it/Bacheca/IGCP437FinalConference/AbstractBook/Morner175_176.pdf | date=10 February | year=2005}} | |||
* | |||
* {{Web reference | title=Physical Agents of Land Loss: Relative Sea Level | work=An Overview of Coastal Land Loss: With Emphasis on the Southeastern United States | URL=http://pubs.usgs.gov/of/2003/of03-337/global.html | date=14 February | year=2005}} | |||
* (NASA; links to multiple measurements) | |||
* | |||
* | |||
* | |||
* | |||
* | |||
* {{cite web |title=Surging Seas in a Warming World: The latest science on present-day impacts and future projections of sea-level rise |url=https://www.un.org/sites/un2.un.org/files/slr_technical_brief_26_aug_2024.pdf |publisher=United Nations |archive-url=https://archive.today/20241020183035/https://www.un.org/sites/un2.un.org/files/slr_technical_brief_26_aug_2024.pdf |archive-date=20 October 2024 |date=26 August 2024 |url-status=live}} | |||
{{World topic|Sea level rise in|title=Sea level rise by country|noredlinks=yes|state=collapsed}} | |||
{{Physical oceanography|expanded=other}} | |||
{{Climate change}} | |||
{{Doomsday}} | |||
* , from the ] | |||
* | |||
* | |||
* (]) | |||
* | |||
{{DEFAULTSORT:Sea Level Rise}} | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] | |||
] |
Latest revision as of 12:14, 15 January 2025
Rise in sea levels due to climate change This article is about the current and projected rise in the world's average sea level. For sea level rise in general, see Past sea level. "Rising seas" redirects here. For the song, see Rising Seas (song).
Between 1901 and 2018, the average sea level rose by 15–25 cm (6–10 in), with an increase of 2.3 mm (0.091 in) per year since the 1970s. This was faster than the sea level had ever risen over at least the past 3,000 years. The rate accelerated to 4.62 mm (0.182 in)/yr for the decade 2013–2022. Climate change due to human activities is the main cause. Between 1993 and 2018, melting ice sheets and glaciers accounted for 44% of sea level rise, with another 42% resulting from thermal expansion of water.
Sea level rise lags behind changes in the Earth's temperature by many decades, and sea level rise will therefore continue to accelerate between now and 2050 in response to warming that has already happened. What happens after that depends on human greenhouse gas emissions. If there are very deep cuts in emissions, sea level rise would slow between 2050 and 2100. It could then reach by 2100 slightly over 30 cm (1 ft) from now and approximately 60 cm (2 ft) from the 19th century. With high emissions it would instead accelerate further, and could rise by 1.0 m (3+1⁄3 ft) or even 1.6 m (5+1⁄3 ft) by 2100. In the long run, sea level rise would amount to 2–3 m (7–10 ft) over the next 2000 years if warming stays to its current 1.5 °C (2.7 °F) over the pre-industrial past. It would be 19–22 metres (62–72 ft) if warming peaks at 5 °C (9.0 °F).
Rising seas affect every coastal and island population on Earth. This can be through flooding, higher storm surges, king tides, and tsunamis. There are many knock-on effects. They lead to loss of coastal ecosystems like mangroves. Crop yields may reduce because of increasing salt levels in irrigation water. Damage to ports disrupts sea trade. The sea level rise projected by 2050 will expose places currently inhabited by tens of millions of people to annual flooding. Without a sharp reduction in greenhouse gas emissions, this may increase to hundreds of millions in the latter decades of the century.
Local factors like tidal range or land subsidence will greatly affect the severity of impacts. For instance, sea level rise in the United States is likely to be two to three times greater than the global average by the end of the century. Yet, of the 20 countries with the greatest exposure to sea level rise, twelve are in Asia, including Indonesia, Bangladesh and the Philippines. The resilience and adaptive capacity of ecosystems and countries also varies, which will result in more or less pronounced impacts. The greatest impact on human populations in the near term will occur in the low-lying Caribbean and Pacific islands. Sea level rise will make many of them uninhabitable later this century.
Societies can adapt to sea level rise in multiple ways. Managed retreat, accommodating coastal change, or protecting against sea level rise through hard-construction practices like seawalls are hard approaches. There are also soft approaches such as dune rehabilitation and beach nourishment. Sometimes these adaptation strategies go hand in hand. At other times choices must be made among different strategies. Poorer nations may also struggle to implement the same approaches to adapt to sea level rise as richer states.
Observations
Between 1901 and 2018, the global mean sea level rose by about 20 cm (7.9 in). More precise data gathered from satellite radar measurements found an increase of 7.5 cm (3.0 in) from 1993 to 2017 (average of 2.9 mm (0.11 in)/yr). This accelerated to 4.62 mm (0.182 in)/yr for 2013–2022. Paleoclimate data shows that this rate of sea level rise is the fastest it had been over at least the past 3,000 years.
While sea level rise is uniform around the globe, some land masses are moving up or down as a consequence of subsidence (land sinking or settling) or post-glacial rebound (land rising as melting ice reduces weight). Therefore, local relative sea level rise may be higher or lower than the global average. Changing ice masses also affect the distribution of sea water around the globe through gravity.
Projections
Approaches used for projections
Several approaches are used for sea level rise (SLR) projections. One is process-based modeling, where ice melting is computed through an ice-sheet model and rising sea temperature and expansion through a general circulation model, and then these contributions are added up. The so-called semi-empirical approach instead applies statistical techniques and basic physical modeling to the observed sea level rise and its reconstructions from the historical geological data (known as paleoclimate modeling). It was developed because process-based model projections in the past IPCC reports (such as the Fourth Assessment Report from 2007) were found to underestimate the already observed sea level rise.
By 2013, improvements in modeling had addressed this issue, and model and semi-empirical projections for the year 2100 are now very similar. Yet, semi-empirical estimates are reliant on the quality of available observations and struggle to represent non-linearities, while processes without enough available information about them cannot be modeled. Thus, another approach is to combine the opinions of a large number of scientists in what is known as a structured expert judgement (SEJ).
Variations of these primary approaches exist. For instance, large climate models are always in demand, so less complex models are often used in their place for simpler tasks like projecting flood risk in the specific regions. A structured expert judgement may be used in combination with modeling to determine which outcomes are more or less likely, which is known as "shifted SEJ". Semi-empirical techniques can be combined with the so-called "intermediate-complexity" models. After 2016, some ice sheet modeling exhibited the so-called ice cliff instability in Antarctica, which results in substantially faster disintegration and retreat than otherwise simulated. The differences are limited with low warming, but at higher warming levels, ice cliff instability predicts far greater sea level rise than any other approach.
Projections for the 21st century
The Intergovernmental Panel on Climate Change is the largest and most influential scientific organization on climate change, and since 1990, it provides several plausible scenarios of 21st century sea level rise in each of its major reports. The differences between scenarios are mainly due to uncertainty about future greenhouse gas emissions. These depend on future economic developments, and also future political action which is hard to predict. Each scenario provides an estimate for sea level rise as a range with a lower and upper limit to reflect the unknowns. The scenarios in the 2013–2014 Fifth Assessment Report (AR5) were called Representative Concentration Pathways, or RCPs and the scenarios in the IPCC Sixth Assessment Report (AR6) are known as Shared Socioeconomic Pathways, or SSPs. A large difference between the two was the addition of SSP1-1.9 to AR6, which represents meeting the best Paris climate agreement goal of 1.5 °C (2.7 °F). In that case, the likely range of sea level rise by 2100 is 28–55 cm (11–21+1⁄2 in).
The lowest scenario in AR5, RCP2.6, would see greenhouse gas emissions low enough to meet the goal of limiting warming by 2100 to 2 °C (3.6 °F). It shows sea level rise in 2100 of about 44 cm (17 in) with a range of 28–61 cm (11–24 in). The "moderate" scenario, where CO2 emissions take a decade or two to peak and its atmospheric concentration does not plateau until the 2070s is called RCP 4.5. Its likely range of sea level rise is 36–71 cm (14–28 in). The highest scenario in RCP8.5 pathway sea level would rise between 52 and 98 cm (20+1⁄2 and 38+1⁄2 in). AR6 had equivalents for both scenarios, but it estimated larger sea level rise under both. In AR6, the SSP1-2.6 pathway results in a range of 32–62 cm (12+1⁄2–24+1⁄2 in) by 2100. The "moderate" SSP2-4.5 results in a 44–76 cm (17+1⁄2–30 in) range by 2100 and SSP5-8.5 led to 65–101 cm (25+1⁄2–40 in).
This general increase of projections in AR6 came after the improvements in ice-sheet modeling and the incorporation of structured expert judgements. These decisions came as the observed ice-sheet erosion in Greenland and Antarctica had matched the upper-end range of the AR5 projections by 2020, and the finding that AR5 projections were likely too slow next to an extrapolation of observed sea level rise trends, while the subsequent reports had improved in this regard. Further, AR5 was criticized by multiple researchers for excluding detailed estimates the impact of "low-confidence" processes like marine ice sheet and marine ice cliff instability, which can substantially accelerate ice loss to potentially add "tens of centimeters" to sea level rise within this century. AR6 includes a version of SSP5-8.5 where these processes take place, and in that case, sea level rise of up to 1.6 m (5+1⁄3 ft) by 2100 could not be ruled out.
Role of instability processes
The greatest uncertainty with sea level rise projections is associated with the so-called marine ice sheet instability (MISI), and, even more so, Marine Ice Cliff Instability (MICI). These processes are mainly associated with West Antarctic Ice Sheet, but may also apply to some of Greenland's glaciers. The former suggests that when glaciers are mostly underwater on retrograde (backwards-sloping) bedrock, the water melts more and more of their height as their retreat continues, thus accelerating their breakdown on its own. This is widely accepted, but is difficult to model.
The latter posits that coastal ice cliffs which exceed ~90 m (295+1⁄2 ft) in above-ground height and are ~800 m (2,624+1⁄2 ft) in basal (underground) height are likely to rapidly collapse under their own weight once the ice shelves propping them up are gone. The collapse then exposes the ice masses following them to the same instability, potentially resulting in a self-sustaining cycle of cliff collapse and rapid ice sheet retreat. This theory had been highly influential - in a 2020 survey of 106 experts, the 2016 paper which suggested 1 m (3+1⁄2 ft) or more of sea level rise by 2100 from Antarctica alone, was considered even more important than the 2014 IPCC Fifth Assessment Report. Even more rapid sea level rise was proposed in a 2016 study led by Jim Hansen, which hypothesized multi-meter sea level rise in 50–100 years as a plausible outcome of high emissions, but it remains a minority view amongst the scientific community.
Marine ice cliff instability had also been very controversial, since it was proposed as a modelling exercise, and the observational evidence from both the past and the present is very limited and ambiguous. So far, only one episode of seabed gouging by ice from the Younger Dryas period appears truly consistent with this theory, but it had lasted for an estimated 900 years, so it is unclear if it supports rapid sea level rise in the present. Modelling which investigated the hypothesis after 2016 often suggested that the ice shelves in the real world may collapse too slowly to make this scenario relevant, or that ice mélange - debris produced as the glacier breaks down - would quickly build up in front of the glacier and significantly slow or even outright stop the instability soon after it began.
Due to these uncertainties, some scientists - including the originators of the hypothesis, Robert DeConto and David Pollard - have suggested that the best way to resolve the question would be to precisely determine sea level rise during the Last Interglacial. MICI can be effectively ruled out if SLR at the time was lower than 4 m (13 ft), while it is very likely if the SLR was greater than 6 m (19+1⁄2 ft). As of 2023, the most recent analysis indicates that the Last Interglacial SLR is unlikely to have been higher than 2.7 m (9 ft), as higher values in other research, such as 5.7 m (18+1⁄2 ft), appear inconsistent with the new paleoclimate data from The Bahamas and the known history of the Greenland Ice Sheet.
Post-2100 sea level rise
Even if the temperature stabilizes, significant sea-level rise (SLR) will continue for centuries, consistent with paleo records of sea level rise. This is due to the high level of inertia in the carbon cycle and the climate system, owing to factors such as the slow diffusion of heat into the deep ocean, leading to a longer climate response time. A 2018 paper estimated that sea level rise in 2300 would increase by a median of 20 cm (8 in) for every five years CO2 emissions increase before peaking. It shows a 5% likelihood of a 1 m (3+1⁄2 ft) increase due to the same. The same estimate found that if the temperature stabilized below 2 °C (3.6 °F), 2300 sea level rise would still exceed 1.5 m (5 ft). Early net zero and slowly falling temperatures could limit it to 70–120 cm (27+1⁄2–47 in).
By 2021, the IPCC Sixth Assessment Report was able to provide estimates for sea level rise in 2150. Keeping warming to 1.5 °C under the SSP1-1.9 scenario would result in sea level rise in the 17–83% range of 37–86 cm (14+1⁄2–34 in). In the SSP1-2.6 pathway the range would be 46–99 cm (18–39 in), for SSP2-4.5 a 66–133 cm (26–52+1⁄2 in) range by 2100 and for SSP5-8.5 a rise of 98–188 cm (38+1⁄2–74 in). It stated that the "low-confidence, high impact" projected 0.63–1.60 m (2–5 ft) mean sea level rise by 2100, and that by 2150, the total sea level rise in his scenario would be in the range of 0.98–4.82 m (3–16 ft) by 2150. AR6 also provided lower-confidence estimates for year 2300 sea level rise under SSP1-2.6 and SSP5-8.5 with various impact assumptions. In the best case scenario, under SSP1-2.6 with no ice sheet acceleration after 2100, the estimate was only 0.8–2.0 metres (2.6–6.6 ft). In the worst estimated scenario, SSP-8.5 with ice cliff instability, the projected range for total sea level rise was 9.5–16.2 metres (31–53 ft) by the year 2300.
Projections for subsequent years are more difficult. In 2019, when 22 experts on ice sheets were asked to estimate 2200 and 2300 SLR under the 5 °C warming scenario, there were 90% confidence intervals of −10 cm (4 in) to 740 cm (24+1⁄2 ft) and −9 cm (3+1⁄2 in) to 970 cm (32 ft), respectively. (Negative values represent the extremely low probability of large climate change-induced increases in precipitation greatly elevating ice sheet surface mass balance.) In 2020, 106 experts who contributed to 6 or more papers on sea level estimated median 118 cm (46+1⁄2 in) SLR in the year 2300 for the low-warming RCP2.6 scenario and the median of 329 cm (129+1⁄2 in) for the high-warming RCP8.5. The former scenario had the 5%–95% confidence range of 24–311 cm (9+1⁄2–122+1⁄2 in), and the latter of 88–783 cm (34+1⁄2–308+1⁄2 in).
After 500 years, sea level rise from thermal expansion alone may have reached only half of its eventual level - likely within ranges of 0.5–2 m (1+1⁄2–6+1⁄2 ft). Additionally, tipping points of Greenland and Antarctica ice sheets are likely to play a larger role over such timescales. Ice loss from Antarctica is likely to dominate very long-term SLR, especially if the warming exceeds 2 °C (3.6 °F). Continued carbon dioxide emissions from fossil fuel sources could cause additional tens of metres of sea level rise, over the next millennia. Burning of all fossil fuels on Earth is sufficient to melt the entire Antarctic ice sheet, causing about 58 m (190 ft) of sea level rise.
Year 2021 IPCC estimates for the amount of sea level rise over the next 2,000 years project that:
- At a warming peak of 1.5 °C (2.7 °F), global sea levels would rise 2–3 m (6+1⁄2–10 ft)
- At a warming peak of 2 °C (3.6 °F), sea levels would rise 2–6 m (6+1⁄2–19+1⁄2 ft)
- At a warming peak of 5 °C (9.0 °F), sea levels would rise 19–22 m (62+1⁄2–72 ft)
Sea levels would continue to rise for several thousand years after the ceasing of emissions, due to the slow nature of climate response to heat. The same estimates on a timescale of 10,000 years project that:
- At a warming peak of 1.5 °C (2.7 °F), global sea levels would rise 6–7 m (19+1⁄2–23 ft)
- At a warming peak of 2 °C (3.6 °F), sea levels would rise 8–13 m (26–42+1⁄2 ft)
- At a warming peak of 5 °C (9.0 °F), sea levels would rise 28–37 m (92–121+1⁄2 ft)
Measurements
Variations in the amount of water in the oceans, changes in its volume, or varying land elevation compared to the sea surface can drive sea level changes. Over a consistent time period, assessments can attribute contributions to sea level rise and provide early indications of change in trajectory. This helps to inform adaptation plans. The different techniques used to measure changes in sea level do not measure exactly the same level. Tide gauges can only measure relative sea level. Satellites can also measure absolute sea level changes. To get precise measurements for sea level, researchers studying the ice and oceans factor in ongoing deformations of the solid Earth. They look in particular at landmasses still rising from past ice masses retreating, and the Earth's gravity and rotation.
Satellites
Since the launch of TOPEX/Poseidon in 1992, an overlapping series of altimetric satellites has been continuously recording the sea level and its changes. These satellites can measure the hills and valleys in the sea caused by currents and detect trends in their height. To measure the distance to the sea surface, the satellites send a microwave pulse towards Earth and record the time it takes to return after reflecting off the ocean's surface. Microwave radiometers correct the additional delay caused by water vapor in the atmosphere. Combining these data with the location of the spacecraft determines the sea-surface height to within a few centimetres. These satellite measurements have estimated rates of sea level rise for 1993–2017 at 3.0 ± 0.4 millimetres (1⁄8 ± 1⁄64 in) per year.
Satellites are useful for measuring regional variations in sea level. An example is the substantial rise between 1993 and 2012 in the western tropical Pacific. This sharp rise has been linked to increasing trade winds. These occur when the Pacific Decadal Oscillation (PDO) and the El Niño–Southern Oscillation (ENSO) change from one state to the other. The PDO is a basin-wide climate pattern consisting of two phases, each commonly lasting 10 to 30 years. The ENSO has a shorter period of 2 to 7 years.
Tide gauges
The global network of tide gauges is the other important source of sea-level observations. Compared to the satellite record, this record has major spatial gaps but covers a much longer period. Coverage of tide gauges started mainly in the Northern Hemisphere. Data for the Southern Hemisphere remained scarce up to the 1970s. The longest running sea-level measurements, NAP or Amsterdam Ordnance Datum were established in 1675, in Amsterdam. Record collection is also extensive in Australia. They include measurements by Thomas Lempriere, an amateur meteorologist, beginning in 1837. Lempriere established a sea-level benchmark on a small cliff on the Isle of the Dead near the Port Arthur convict settlement in 1841.
Together with satellite data for the period after 1992, this network established that global mean sea level rose 19.5 cm (7.7 in) between 1870 and 2004 at an average rate of about 1.44 mm/yr. (For the 20th century the average is 1.7 mm/yr.) By 2018, data collected by Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) had shown that the global mean sea level was rising by 3.2 mm (1⁄8 in) per year. This was double the average 20th century rate. The 2023 World Meteorological Organization report found further acceleration to 4.62 mm/yr over the 2013–2022 period. These observations help to check and verify predictions from climate change simulations.
Regional differences are also visible in the tide gauge data. Some are caused by local sea level differences. Others are due to vertical land movements. In Europe, only some land areas are rising while the others are sinking. Since 1970, most tidal stations have measured higher seas. However sea levels along the northern Baltic Sea have dropped due to post-glacial rebound.
Past sea level rise
Main articles: Past sea level, Sea level § Change, and Marine transgressionAn understanding of past sea level is an important guide to where current changes in sea level will end up. In the recent geological past, thermal expansion from increased temperatures and changes in land ice are the dominant reasons of sea level rise. The last time that the Earth was 2 °C (3.6 °F) warmer than pre-industrial temperatures was 120,000 years ago. This was when warming due to Milankovitch cycles (changes in the amount of sunlight due to slow changes in the Earth's orbit) caused the Eemian interglacial. Sea levels during that warmer interglacial were at least 5 m (16 ft) higher than now. The Eemian warming was sustained over a period of thousands of years. The size of the rise in sea level implies a large contribution from the Antarctic and Greenland ice sheets. Levels of atmospheric carbon dioxide of around 400 parts per million (similar to 2000s) had increased temperature by over 2–3 °C (3.6–5.4 °F) around three million years ago. This temperature increase eventually melted one third of Antarctica's ice sheet, causing sea levels to rise 20 meters above the preindustrial levels.
Since the Last Glacial Maximum, about 20,000 years ago, sea level has risen by more than 125 metres (410 ft). Rates vary from less than 1 mm/year during the pre-industrial era to 40+ mm/year when major ice sheets over Canada and Eurasia melted. Meltwater pulses are periods of fast sea level rise caused by the rapid disintegration of these ice sheets. The rate of sea level rise started to slow down about 8,200 years before today. Sea level was almost constant for the last 2,500 years. The recent trend of rising sea level started at the end of the 19th or beginning of the 20th century.
Causes
Effects of climate change
See also: Effects of climate changeThe three main reasons why global warming causes sea levels to rise are the expansion of oceans due to heating, water inflow from melting ice sheets and water inflow from glaciers. Other factors affecting sea level rise include changes in snow mass, and flow from terrestrial water storage, though the contribution from these is thought to be small. Glacier retreat and ocean expansion have dominated sea level rise since the start of the 20th century. Some of the losses from glaciers are offset when precipitation falls as snow, accumulates and over time forms glacial ice. If precipitation, surface processes and ice loss at the edge balance each other, sea level remains the same. Because of this precipitation began as water vapor evaporated from the ocean surface, effects of climate change on the water cycle can even increase ice build-up. However, this effect is not enough to fully offset ice losses, and sea level rise continues to accelerate.
The contributions of the two large ice sheets, in Greenland and Antarctica, are likely to increase in the 21st century. They store most of the land ice (~99.5%) and have a sea-level equivalent (SLE) of 7.4 m (24 ft 3 in) for Greenland and 58.3 m (191 ft 3 in) for Antarctica. Thus, melting of all the ice on Earth would result in about 70 m (229 ft 8 in) of sea level rise, although this would require at least 10,000 years and up to 10 °C (18 °F) of global warming.
Ocean heating
Main article: Ocean heat contentThe oceans store more than 90% of the extra heat added to the climate system by Earth's energy imbalance and act as a buffer against its effects. This means that the same amount of heat that would increase the average world ocean temperature by 0.01 °C (0.018 °F) would increase atmospheric temperature by approximately 10 °C (18 °F). So a small change in the mean temperature of the ocean represents a very large change in the total heat content of the climate system. Winds and currents move heat into deeper parts of the ocean. Some of it reaches depths of more than 2,000 m (6,600 ft).
When the ocean gains heat, the water expands and sea level rises. Warmer water and water under great pressure (due to depth) expand more than cooler water and water under less pressure. Consequently, cold Arctic Ocean water will expand less than warm tropical water. Different climate models present slightly different patterns of ocean heating. So their projections do not agree fully on how much ocean heating contributes to sea level rise.
Ice loss on the Antarctic continent
The large volume of ice on the Antarctic continent stores around 60% of the world's fresh water. Excluding groundwater this is 90%. Antarctica is experiencing ice loss from coastal glaciers in the West Antarctica and some glaciers of East Antarctica. However it is gaining mass from the increased snow build-up inland, particularly in the East. This leads to contradicting trends. There are different satellite methods for measuring ice mass and change. Combining them helps to reconcile the differences. However, there can still be variations between the studies. In 2018, a systematic review estimated average annual ice loss of 43 billion tons (Gt) across the entire continent between 1992 and 2002. This tripled to an annual average of 220 Gt from 2012 to 2017. However, a 2021 analysis of data from four different research satellite systems (Envisat, European Remote-Sensing Satellite, GRACE and GRACE-FO and ICESat) indicated annual mass loss of only about 12 Gt from 2012 to 2016. This was due to greater ice gain in East Antarctica than estimated earlier.
In the future, it is known that West Antarctica at least will continue to lose mass, and the likely future losses of sea ice and ice shelves, which block warmer currents from direct contact with the ice sheet, can accelerate declines even in East Antarctica. Altogether, Antarctica is the source of the largest uncertainty for future sea level projections. In 2019, the SROCC assessed several studies attempting to estimate 2300 sea level rise caused by ice loss in Antarctica alone, arriving at projected estimates of 0.07–0.37 metres (0.23–1.21 ft) for the low emission RCP2.6 scenario, and 0.60–2.89 metres (2.0–9.5 ft) in the high emission RCP8.5 scenario. This wide range of estimates is mainly due to the uncertainties regarding marine ice sheet and marine ice cliff instabilities.
East Antarctica
Further information: East Antarctic Ice SheetThe world's largest potential source of sea level rise is the East Antarctic Ice Sheet (EAIS). It is 2.2 km thick on average and holds enough ice to raise global sea levels by 53.3 m (174 ft 10 in) Its great thickness and high elevation make it more stable than the other ice sheets. As of the early 2020s, most studies show that it is still gaining mass. Some analyses have suggested it began to lose mass in the 2000s. However they over-extrapolated some observed losses on to the poorly observed areas. A more complete observational record shows continued mass gain.
In spite of the net mass gain, some East Antarctica glaciers have lost ice in recent decades due to ocean warming and declining structural support from the local sea ice, such as Denman Glacier, and Totten Glacier. Totten Glacier is particularly important because it stabilizes the Aurora Subglacial Basin. Subglacial basins like Aurora and Wilkes Basin are major ice reservoirs together holding as much ice as all of West Antarctica. They are more vulnerable than the rest of East Antarctica. Their collective tipping point probably lies at around 3 °C (5.4 °F) of global warming. It may be as high as 6 °C (11 °F) or as low as 2 °C (3.6 °F). Once this tipping point is crossed, the collapse of these subglacial basins could take place over as little as 500 or as much as 10,000 years. The median timeline is 2000 years. Depending on how many subglacial basins are vulnerable, this causes sea level rise of between 1.4 m (4 ft 7 in) and 6.4 m (21 ft 0 in).
On the other hand, the whole EAIS would not definitely collapse until global warming reaches 7.5 °C (13.5 °F), with a range between 5 °C (9.0 °F) and 10 °C (18 °F). It would take at least 10,000 years to disappear. Some scientists have estimated that warming would have to reach at least 6 °C (11 °F) to melt two thirds of its volume.
West Antarctica
Further information: West Antarctic Ice SheetEast Antarctica contains the largest potential source of sea level rise. However the West Antarctic ice sheet (WAIS) is substantially more vulnerable. Temperatures on West Antarctica have increased significantly, unlike East Antarctica and the Antarctic Peninsula. The trend is between 0.08 °C (0.14 °F) and 0.96 °C (1.73 °F) per decade between 1976 and 2012. Satellite observations recorded a substantial increase in WAIS melting from 1992 to 2017. This resulted in 7.6 ± 3.9 mm (19⁄64 ± 5⁄32 in) of Antarctica sea level rise. Outflow glaciers in the Amundsen Sea Embayment played a disproportionate role.
The median estimated increase in sea level rise from Antarctica by 2100 is ~11 cm (5 in). There is no difference between scenarios, because the increased warming would intensify the water cycle and increase snowfall accumulation over the EAIS at about the same rate as it would increase ice loss from WAIS. However, most of the bedrock underlying the WAIS lies well below sea level, and it has to be buttressed by the Thwaites and Pine Island glaciers. If these glaciers were to collapse, the entire ice sheet would as well. Their disappearance would take at least several centuries, but is considered almost inevitable, as their bedrock topography deepens inland and becomes more vulnerable to meltwater, in what is known as marine ice sheet instability.
The contribution of these glaciers to global sea levels has already accelerated since the year 2000. The Thwaites Glacier now accounts for 4% of global sea level rise. It could start to lose even more ice if the Thwaites Ice Shelf fails and would no longer stabilize it, which could potentially occur in mid-2020s. A combination of ice sheet instability with other important but hard-to-model processes like hydrofracturing (meltwater collects atop the ice sheet, pools into fractures and forces them open) or smaller-scale changes in ocean circulation could cause the WAIS to contribute up to 41 cm (16 in) by 2100 under the low-emission scenario and up to 57 cm (22 in) under the highest-emission one. Ice cliff instability would cause a contribution of 1 m (3+1⁄2 ft) or more if it were applicable.
The melting of all the ice in West Antarctica would increase the total sea level rise to 4.3 m (14 ft 1 in). However, mountain ice caps not in contact with water are less vulnerable than the majority of the ice sheet, which is located below the sea level. Its collapse would cause ~3.3 m (10 ft 10 in) of sea level rise. This disappearance would take an estimated 2000 years. The absolute minimum for the loss of West Antarctica ice is 500 years, and the potential maximum is 13,000 years.
Once ice loss from the West Antarctica is triggered, the only way to restore it to near-present values is by lowering the global temperature to 1 °C (1.8 °F) below the preindustrial level. This would be 2 °C (3.6 °F) below the temperature of 2020. Other researchers suggested that a climate engineering intervention to stabilize the ice sheet's glaciers may delay its loss by centuries and give more time to adapt. However this is an uncertain proposal, and would end up as one of the most expensive projects ever attempted.
Ice sheet loss in Greenland
Most ice on Greenland is in the Greenland ice sheet which is 3 km (10,000 ft) at its thickest. The rest of Greenland ice forms isolated glaciers and ice caps. The average annual ice loss in Greenland more than doubled in the early 21st century compared to the 20th century. Its contribution to sea level rise correspondingly increased from 0.07 mm per year between 1992 and 1997 to 0.68 mm per year between 2012 and 2017. Total ice loss from the Greenland ice sheet between 1992 and 2018 amounted to 3,902 gigatons (Gt) of ice. This is equivalent to a SLR contribution of 10.8 mm. The contribution for the 2012–2016 period was equivalent to 37% of sea level rise from land ice sources (excluding thermal expansion). This observed rate of ice sheet melting is at the higher end of predictions from past IPCC assessment reports.
In 2021, AR6 estimated that by 2100, the melting of Greenland ice sheet would most likely add around 6 cm (2+1⁄2 in) to sea levels under the low-emission scenario, and 13 cm (5 in) under the high-emission scenario. The first scenario, SSP1-2.6, largely fulfils the Paris Agreement goals, while the other, SSP5-8.5, has the emissions accelerate throughout the century. The uncertainty about ice sheet dynamics can affect both pathways. In the best-case scenario, ice sheet under SSP1-2.6 gains enough mass by 2100 through surface mass balance feedbacks to reduce the sea levels by 2 cm (1 in). In the worst case, it adds 15 cm (6 in). For SSP5-8.5, the best-case scenario is adding 5 cm (2 in) to sea levels, and the worst-case is adding 23 cm (9 in).
Greenland's peripheral glaciers and ice caps crossed an irreversible tipping point around 1997. Sea level rise from their loss is now unstoppable. However the temperature changes in future, the warming of 2000–2019 had already damaged the ice sheet enough for it to eventually lose ~3.3% of its volume. This is leading to 27 cm (10+1⁄2 in) of future sea level rise. At a certain level of global warming, the Greenland ice sheet will almost completely melt. Ice cores show this happened at least once over the last million years, during which the temperatures have at most been 2.5 °C (4.5 °F) warmer than the preindustrial average.
2012 modelling suggested that the tipping point of the ice sheet was between 0.8 °C (1.4 °F) and 3.2 °C (5.8 °F). 2023 modelling has narrowed the tipping threshold to a 1.7 °C (3.1 °F)-2.3 °C (4.1 °F) range, which is consistent with the empirical 2.5 °C (4.5 °F) upper limit from ice cores. If temperatures reach or exceed that level, reducing the global temperature to 1.5 °C (2.7 °F) above pre-industrial levels or lower would prevent the loss of the entire ice sheet. One way to do this in theory would be large-scale carbon dioxide removal, but there would still be cause of greater ice losses and sea level rise from Greenland than if the threshold was not breached in the first place. If the tipping point instead is durably but mildly crossed, the ice sheet would take between 10,000 and 15,000 years to disintegrate entirel, with a most likely estimate of 10,000 years. If climate change continues along its worst trajectory and temperatures continue to rise quickly over multiple centuries, it would only take 1,000 years.
Mountain glacier loss
There are roughly 200,000 glaciers on Earth, which are spread out across all continents. Less than 1% of glacier ice is in mountain glaciers, compared to 99% in Greenland and Antarctica. However, this small size also makes mountain glaciers more vulnerable to melting than the larger ice sheets. This means they have had a disproportionate contribution to historical sea level rise and are set to contribute a smaller, but still significant fraction of sea level rise in the 21st century. Observational and modelling studies of mass loss from glaciers and ice caps show they contribute 0.2-0.4 mm per year to sea level rise, averaged over the 20th century. The contribution for the 2012–2016 period was nearly as large as that of Greenland. It was 0.63 mm of sea level rise per year, equivalent to 34% of sea level rise from land ice sources. Glaciers contributed around 40% to sea level rise during the 20th century, with estimates for the 21st century of around 30%.
In 2023, a Science paper estimated that at 1.5 °C (2.7 °F), one quarter of mountain glacier mass would be lost by 2100 and nearly half would be lost at 4 °C (7.2 °F), contributing ~9 cm (3+1⁄2 in) and ~15 cm (6 in) to sea level rise, respectively. Glacier mass is disproportionately concentrated in the most resilient glaciers. So in practice this would remove 49-83% of glacier formations. It further estimated that the current likely trajectory of 2.7 °C (4.9 °F) would result in the SLR contribution of ~11 cm (4+1⁄2 in) by 2100. Mountain glaciers are even more vulnerable over the longer term. In 2022, another Science paper estimated that almost no mountain glaciers could survive once warming crosses 2 °C (3.6 °F). Their complete loss is largely inevitable around 3 °C (5.4 °F). There is even a possibility of complete loss after 2100 at just 1.5 °C (2.7 °F). This could happen as early as 50 years after the tipping point is crossed, although 200 years is the most likely value, and the maximum is around 1000 years.
Sea ice loss
Sea ice loss contributes very slightly to global sea level rise. If the melt water from ice floating in the sea was exactly the same as sea water then, according to Archimedes' principle, no rise would occur. However melted sea ice contains less dissolved salt than sea water and is therefore less dense, with a slightly greater volume per unit of mass. If all floating ice shelves and icebergs were to melt sea level would only rise by about 4 cm (1+1⁄2 in).
Changes to land water storage
See also: Groundwater-related subsidenceHuman activity impacts how much water is stored on land. Dams retain large quantities of water, which is stored on land rather than flowing into the sea, though the total quantity stored will vary from time to time. On the other hand, humans extract water from lakes, wetlands and underground reservoirs for drinking and food production. This often causes subsidence. Furthermore, the hydrological cycle is influenced by climate change and deforestation. In the 20th century, these processes had approximately cancelled out each other's impact on sea level rise, but dam building has slowed down and is expected to stay low for the 21st century.
Water redistribution caused by irrigation from 1993 to 2010 caused a drift of Earth's rotational pole by 78.48 centimetres (30.90 in). This caused groundwater depletion equivalent to a global sea level rise of 6.24 millimetres (0.246 in).
Impacts
See also: Human impacts on coasts, Coastal development hazards, and Coastal erosionOn people and societies
High tide flooding, also called tidal flooding, has become much more common in the past seven decades.The number of floods declared to be disasters by the Federal Emergency Management Agency (FEMA) has increased, especially since 2010.Sea-level rise has many impacts. They include higher and more frequent high-tide and storm-surge flooding and increased coastal erosion. Other impacts are inhibition of primary production processes, more extensive coastal inundation, and changes in surface water quality and groundwater. These can lead to a greater loss of property and coastal habitats, loss of life during floods and loss of cultural resources. There are also impacts on agriculture and aquaculture. There can also be loss of tourism, recreation, and transport-related functions. Land use changes such as urbanisation or deforestation of low-lying coastal zones exacerbate coastal flooding impacts. Regions already vulnerable to rising sea level also struggle with coastal flooding. This washes away land and alters the landscape.
Changes in emissions are likely to have only a small effect on the extent of sea level rise by 2050. So projected sea level rise could put tens of millions of people at risk by then. Scientists estimate that 2050 levels of sea level rise would result in about 150 million people under the water line during high tide. About 300 million would be in places flooded every year. This projection is based on the distribution of population in 2010. It does not take into account the effects of population growth and human migration. These figures are 40 million and 50 million more respectively than the numbers at risk in 2010. By 2100, there would be another 40 million people under the water line during high tide if sea level rise remains low. This figure would be 80 million for a high estimate of median sea level rise. Ice sheet processes under the highest emission scenario would result in sea level rise of well over one metre (3+1⁄4 ft) by 2100. This could be as much as over two metres (6+1⁄2 ft), This could result in as many as 520 million additional people ending up under the water line during high tide and 640 million in places flooded every year, compared to the 2010 population distribution.
Over the longer term, coastal areas are particularly vulnerable to rising sea levels. They are also vulnerable to changes in the frequency and intensity of storms, increased precipitation, and rising ocean temperatures. Ten percent of the world's population live in coastal areas that are less than 10 metres (33 ft) above sea level. Two thirds of the world's cities with over five million people are located in these low-lying coastal areas. About 600 million people live directly on the coast around the world. Cities such as Miami, Rio de Janeiro, Osaka and Shanghai will be especially vulnerable later in the century under warming of 3 °C (5.4 °F). This is close to the current trajectory. LiDAR-based research had established in 2021 that 267 million people worldwide lived on land less than 2 m (6+1⁄2 ft) above sea level. With a 1 m (3+1⁄2 ft) sea level rise and zero population growth, that could increase to 410 million people.
Potential disruption of sea trade and migrations could impact people living further inland. United Nations Secretary-General António Guterres warned in 2023 that sea level rise risks causing human migrations on a "biblical scale". Sea level rise will inevitably affect ports, but there is limited research on this. There is insufficient knowledge about the investments necessary to protect ports currently in use. This includes protecting current facilities before it becomes more reasonable to build new ports elsewhere. Some coastal regions are rich agricultural lands. Their loss to the sea could cause food shortages. This is a particularly acute issue for river deltas such as Nile Delta in Egypt and Red River and Mekong Deltas in Vietnam. Saltwater intrusion into the soil and irrigation water has a disproportionate effect on them.
On ecosystems
See also: Extinction risk from climate changeFlooding and soil/water salinization threaten the habitats of coastal plants, birds, and freshwater/estuarine fish when seawater reaches inland. When coastal forest areas become inundated with saltwater to the point no trees can survive the resulting habitats are called ghost forests. Starting around 2050, some nesting sites in Florida, Cuba, Ecuador and the island of Sint Eustatius for leatherback, loggerhead, hawksbill, green and olive ridley turtles are expected to be flooded. The proportion will increase over time. In 2016, Bramble Cay islet in the Great Barrier Reef was inundated. This flooded the habitat of a rodent named Bramble Cay melomys. It was officially declared extinct in 2019.
Some ecosystems can move inland with the high-water mark. But natural or artificial barriers prevent many from migrating. This coastal narrowing is sometimes called 'coastal squeeze' when it involves human-made barriers. It could result in the loss of habitats such as mudflats and tidal marshes. Mangrove ecosystems on the mudflats of tropical coasts nurture high biodiversity. They are particularly vulnerable due to mangrove plants' reliance on breathing roots or pneumatophores. These will be submerged if the rate is too rapid for them to migrate upward. This would result in the loss of an ecosystem. Both mangroves and tidal marshes protect against storm surges, waves and tsunamis, so their loss makes the effects of sea level rise worse. Human activities such as dam building may restrict sediment supplies to wetlands. This would prevent natural adaptation processes. The loss of some tidal marshes is unavoidable as a consequence.
Corals are important for bird and fish life. They need to grow vertically to remain close to the sea surface in order to get enough energy from sunlight. The corals have so far been able to keep up the vertical growth with the rising seas, but might not be able to do so in the future.
Regional variations
Further information: Relative sea level and Sinking citiesWhen a glacier or ice sheet melts, it loses mass. This reduces its gravitational pull. In some places near current and former glaciers and ice sheets, this has caused water levels to drop. At the same time water levels will increase more than average further away from the ice sheet. Thus ice loss in Greenland affects regional sea level differently than the equivalent loss in Antarctica. On the other hand, the Atlantic is warming at a faster pace than the Pacific. This has consequences for Europe and the U.S. East Coast. The East Coast sea level is rising at 3–4 times the global average. Scientists have linked extreme regional sea level rise on the US Northeast Coast to the downturn of the Atlantic meridional overturning circulation (AMOC).
Many ports, urban conglomerations, and agricultural regions stand on river deltas. Here land subsidence contributes to much higher relative sea level rise. Unsustainable extraction of groundwater and oil and gas is one cause. Levees and other flood management practices are another. They prevent sediments from accumulating. These would otherwise compensate for the natural settling of deltaic soils.
Estimates for total human-caused subsidence in the Rhine-Meuse-Scheldt delta (Netherlands) are 3–4 m (10–13 ft), over 3 m (10 ft) in urban areas of the Mississippi River Delta (New Orleans), and over 9 m (30 ft) in the Sacramento–San Joaquin River Delta. On the other hand, relative sea level around the Hudson Bay in Canada and the northern Baltic Sea is falling due to post-glacial isostatic rebound.
Adaptation
Further information: Climate change adaptation and coastal managementCutting greenhouse gas emissions can slow and stabilize the rate of sea level rise after 2050. This would greatly reduce its costs and damages, but cannot stop it outright. So climate change adaptation to sea level rise is inevitable. The simplest approach is to stop development in vulnerable areas and ultimately move people and infrastructure away from them. Such retreat from sea level rise often results in the loss of livelihoods. The displacement of newly impoverished people could burden their new homes and accelerate social tensions.
It is possible to avoid or at least delay the retreat from sea level rise with enhanced protections. These include dams, levees or improved natural defenses. Other options include updating building standards to reduce damage from floods, addition of storm water valves to address more frequent and severe flooding at high tide, or cultivating crops more tolerant of saltwater in the soil, even at an increased cost. These options divide into hard and soft adaptation. Hard adaptation generally involves large-scale changes to human societies and ecological systems. It often includes the construction of capital-intensive infrastructure. Soft adaptation involves strengthening natural defenses and local community adaptation. This usually involves simple, modular and locally owned technology. The two types of adaptation may be complementary or mutually exclusive. Adaptation options often require significant investment. But the costs of doing nothing are far greater. One example would involve adaptation against flooding. Effective adaptation measures could reduce future annual costs of flooding in 136 of the world's largest coastal cities from $1 trillion by 2050 without adaptation to a little over $60 billion annually. The cost would be $50 billion per year. Some experts argue that retreat from the coast would have a lower impact on the GDP of India and Southeast Asia then attempting to protect every coastline, in the case of very high sea level rise.
To be successful, adaptation must anticipate sea level rise well ahead of time. As of 2023, the global state of adaptation planning is mixed. A survey of 253 planners from 49 countries found that 98% are aware of sea level rise projections, but 26% have not yet formally integrated them into their policy documents. Only around a third of respondents from Asian and South American countries have done so. This compares with 50% in Africa, and over 75% in Europe, Australasia and North America. Some 56% of all surveyed planners have plans which account for 2050 and 2100 sea level rise. But 53% use only a single projection rather than a range of two or three projections. Just 14% use four projections, including the one for "extreme" or "high-end" sea level rise. Another study found that over 75% of regional sea level rise assessments from the West and Northeastern United States included at least three estimates. These are usually RCP2.6, RCP4.5 and RCP8.5, and sometimes include extreme scenarios. But 88% of projections from the American South had only a single estimate. Similarly, no assessment from the South went beyond 2100. By contrast 14 assessments from the West went up to 2150, and three from the Northeast went to 2200. 56% of all localities were also found to underestimate the upper end of sea level rise relative to IPCC Sixth Assessment Report.
By region
Africa
Further information: Climate change in the Middle East and North Africa § Sea level riseIn Africa, future population growth amplifies risks from sea level rise. Some 54.2 million people lived in the highly exposed low elevation coastal zones (LECZ) around 2000. This number will effectively double to around 110 million people by 2030, and then reach 185 to 230 million people by 2060. By then, the average regional sea level rise will be around 21 cm, with little difference from climate change scenarios. By 2100, Egypt, Mozambique and Tanzania are likely to have the largest number of people affected by annual flooding amongst all African countries. And under RCP8.5, 10 important cultural sites would be at risk of flooding and erosion by the end of the century.
In the near term, some of the largest displacement is projected to occur in the East Africa region. At least 750,000 people there are likely to be displaced from the coasts between 2020 and 2050. By 2050, 12 major African cities would collectively sustain cumulative damages of US$65 billion for the "moderate" climate change scenario RCP4.5 and between US$86.5 billion to US$137.5 billion on average: in the worst case, these damages could effectively triple. In all of these estimates, around half of the damages would occur in the Egyptian city of Alexandria. Hundreds of thousands of people in its low-lying areas may already need relocation in the coming decade. Across sub-Saharan Africa as a whole, damage from sea level rise could reach 2–4% of GDP by 2050, although this depends on the extent of future economic growth and climate change adaptation.
Asia
Further information: Climate change in Asia § Sea level riseAsia has the largest population at risk from sea level due to its dense coastal populations. As of 2022, some 63 million people in East and South Asia were already at risk from a 100-year flood. This is largely due to inadequate coastal protection in many countries. Bangladesh, China, India, Indonesia, Japan, Pakistan, the Philippines, Thailand and Vietnam alone account for 70% of people exposed to sea level rise during the 21st century. Sea level rise in Bangladesh is likely to displace 0.9-2.1 million people by 2050. It may also force the relocation of up to one third of power plants as early as 2030, and many of the remaining plants would have to deal with the increased salinity of their cooling water. Nations like Bangladesh, Vietnam and China with extensive rice production on the coast are already seeing adverse impacts from saltwater intrusion.
Modelling results predict that Asia will suffer direct economic damages of US$167.6 billion at 0.47 meters of sea level rise. This rises to US$272.3 billion at 1.12 meters and US$338.1 billion at 1.75 meters. There is an additional indirect impact of US$8.5, 24 or 15 billion from population displacement at those levels. China, India, the Republic of Korea, Japan, Indonesia and Russia experience the largest economic losses. Out of the 20 coastal cities expected to see the highest flood losses by 2050, 13 are in Asia. Nine of these are the so-called sinking cities, where subsidence (typically caused by unsustainable groundwater extraction in the past) would compound sea level rise. These are Bangkok, Guangzhou, Ho Chi Minh City, Jakarta, Kolkata, Nagoya, Tianjin, Xiamen and Zhanjiang.
By 2050, Guangzhou would see 0.2 meters of sea level rise and estimated annual economic losses of US$254 million – the highest in the world. In Shanghai, coastal inundation amounts to about 0.03% of local GDP, yet would increase to 0.8% by 2100 even under the "moderate" RCP4.5 scenario in the absence of adaptation. The city of Jakarta is sinking so much (up to 28 cm (11 in) per year between 1982 and 2010 in some areas) that in 2019, the government had committed to relocate the capital of Indonesia to another city.
Australasia
In Australia, erosion and flooding of Queensland's Sunshine Coast beaches is likely to intensify by 60% by 2030. Without adaptation there would be a big impact on tourism. Adaptation costs for sea level rise would be three times higher under the high-emission RCP8.5 scenario than in the low-emission RCP2.6 scenario. Sea level rise of 0.2-0.3 meters is likely by 2050. In these conditions what is currently a 100-year flood would occur every year in the New Zealand cities of Wellington and Christchurch. With 0.5 m sea level rise, a current 100-year flood in Australia would occur several times a year. In New Zealand this would expose buildings with a collective worth of NZ$12.75 billion to new 100-year floods. A meter or so of sea level rise would threaten assets in New Zealand with a worth of NZD$25.5 billion. There would be a disproportionate impact on Maori-owned holdings and cultural heritage objects. Australian assets worth AUS$164–226 billion including many unsealed roads and railway lines would also be at risk. This amounts to a 111% rise in Australia's inundation costs between 2020 and 2100.
Central and South America
By 2100, coastal flooding and erosion will affect at least 3-4 million people in South America. Many people live in low-lying areas exposed to sea level rise. This includes 6% of the population of Venezuela, 56% of the population of Guyana and 68% of the population of Suriname. In Guyana much of the capital Georgetown is already below sea level. In Brazil, the coastal ecoregion of Caatinga is responsible for 99% of its shrimp production. A combination of sea level rise, ocean warming and ocean acidification threaten its unique ecosystem. Extreme wave or wind behavior disrupted the port complex of Santa Catarina 76 times in one 6-year period in the 2010s. There was a US$25,000-50,000 loss for each idle day. In Port of Santos, storm surges were three times more frequent between 2000 and 2016 than between 1928 and 1999.
Europe
Many sandy coastlines in Europe are vulnerable to erosion due to sea level rise. In Spain, Costa del Maresme is likely to retreat by 16 meters by 2050 relative to 2010. This could amount to 52 meters by 2100 under RCP8.5 Other vulnerable coastlines include the Tyrrhenian Sea coast of Italy's Calabria region, the Barra-Vagueira coast in Portugal and Nørlev Strand in Denmark.
In France, it was estimated that 8,000-10,000 people would be forced to migrate away from the coasts by 2080. The Italian city of Venice is located on islands. It is highly vulnerable to flooding and has already spent $6 billion on a barrier system. A quarter of the German state of Schleswig-Holstein, inhabited by over 350,000 people, is at low elevation and has been vulnerable to flooding since preindustrial times. Many levees already exist. Because of its complex geography, the authorities chose a flexible mix of hard and soft measures to cope with sea level rise of over 1 meter per century. In the United Kingdom, sea level at the end of the century would increase by 53 to 115 centimeters at the mouth of the River Thames and 30 to 90 centimeters at Edinburgh. The UK has divided its coast into 22 areas, each covered by a Shoreline Management Plan. Those are sub-divided into 2000 management units, working across three periods of 0–20, 20-50 and 50–100 years.
The Netherlands is a country that sits partially below sea level and is subsiding. It has responded by extending its Delta Works program. Drafted in 2008, the Delta Commission report said that the country must plan for a rise in the North Sea up to 1.3 m (4 ft 3 in) by 2100 and plan for a 2–4 m (7–13 ft) rise by 2200. It advised annual spending between €1.0 and €1.5 billion. This would support measures such as broadening coastal dunes and strengthening sea and river dikes. Worst-case evacuation plans were also drawn up.
North America
As of 2017, around 95 million Americans lived on the coast. The figures for Canada and Mexico were 6.5 million and 19 million. Increased chronic nuisance flooding and king tide flooding is already a problem in the highly vulnerable state of Florida. The US East Coast is also vulnerable. On average, the number of days with tidal flooding in the US increased 2 times in the years 2000–2020, reaching 3–7 days per year. In some areas the increase was much stronger: 4 times in the Southeast Atlantic and 11 times in the Western Gulf. By the year 2030 the average number is expected to be 7–15 days, reaching 25–75 days by 2050. U.S. coastal cities have responded with beach nourishment or beach replenishment. This trucks in mined sand in addition to other adaptation measures such as zoning, restrictions on state funding, and building code standards.
Along an estimated ~15% of the US coastline, the majority of local groundwater levels are already below sea level. This places those groundwater reservoirs at risk of sea water intrusion. That would render fresh water unusable once its concentration exceeds 2-3%. Damage is also widespread in Canada. It will affect major cities like Halifax and more remote locations like Lennox Island. The Mi'kmaq community there is already considering relocation due to widespread coastal erosion. In Mexico, damage from SLR to tourism hotspots like Cancun, Isla Mujeres, Playa del Carmen, Puerto Morelos and Cozumel could amount to US$1.4–2.3 billion. The increase in storm surge due to sea level rise is also a problem. Due to this effect Hurricane Sandy caused an additional US$8 billion in damage, impacted 36,000 more houses and 71,000 more people. In the future, the northern Gulf of Mexico, Atlantic Canada and the Pacific coast of Mexico would experience the greatest sea level rise. By 2030, flooding along the US Gulf Coast could cause economic losses of up to US$176 billion. Using nature-based solutions like wetland restoration and oyster reef restoration could avoid around US$50 billion of this.
By 2050, coastal flooding in the US is likely to rise tenfold to four "moderate" flooding events per year. That forecast is even without storms or heavy rainfall. In New York City, current 100-year flood would occur once in 19–68 years by 2050 and 4–60 years by 2080. By 2050, 20 million people in the greater New York City area would be at risk. This is because 40% of existing water treatment facilities would be compromised and 60% of power plants will need relocation.
By 2100, sea level rise of 0.9 m (3 ft) and 1.8 m (6 ft) would threaten 4.2 and 13.1 million people in the US, respectively. In California alone, 2 m (6+1⁄2 ft) of SLR could affect 600,000 people and threaten over US$150 billion in property with inundation. This potentially represents over 6% of the state's GDP. In North Carolina, a meter of SLR inundates 42% of the Albemarle-Pamlico Peninsula, costing up to US$14 billion. In nine southeast US states, the same level of sea level rise would claim up to 13,000 historical and archaeological sites, including over 1000 sites eligible for inclusion in the National Register for Historic Places.
Island nations
Further information: Effects of climate change on island nations, Small Island Developing States, and Alliance of Small Island StatesSmall island states are nations with populations on atolls and other low islands. Atolls on average reach 0.9–1.8 m (3–6 ft) above sea level. These are the most vulnerable places to coastal erosion, flooding and salt intrusion into soils and freshwater caused by sea level rise. Sea level rise may make an island uninhabitable before it is completely flooded. Already, children in small island states encounter hampered access to food and water. They suffer an increased rate of mental and social disorders due to these stresses. At current rates, sea level rise would be high enough to make the Maldives uninhabitable by 2100. Five of the Solomon Islands have already disappeared due to the effects of sea level rise and stronger trade winds pushing water into the Western Pacific.
Adaptation to sea level rise is costly for small island nations as a large portion of their population lives in areas that are at risk. Nations like Maldives, Kiribati and Tuvalu already have to consider controlled international migration of their population in response to rising seas. The alternative of uncontrolled migration threatens to worsen the humanitarian crisis of climate refugees. In 2014, Kiribati purchased 20 square kilometers of land (about 2.5% of Kiribati's current area) on the Fijian island of Vanua Levu to relocate its population once their own islands are lost to the sea.
Fiji also suffers from sea level rise. It is in a comparatively safer position. Its residents continue to rely on local adaptation like moving further inland and increasing sediment supply to combat erosion instead of relocating entirely. Fiji has also issued a green bond of $50 million to invest in green initiatives and fund adaptation efforts. It is restoring coral reefs and mangroves to protect against flooding and erosion. It sees this as a more cost-efficient alternative to building sea walls. The nations of Palau and Tonga are taking similar steps. Even when an island is not threatened with complete disappearance from flooding, tourism and local economies may end up devastated. For instance, sea level rise of 1.0 m (3 ft 3 in) would cause partial or complete inundation of 29% of coastal resorts in the Caribbean. A further 49–60% of coastal resorts would be at risk from resulting coastal erosion.
See also
- Climate emergency declaration – Emergency proclaimed due to climate change
- Coastal development hazards – Type of anthropogenic effect on the environment
- Effects of climate change on oceans
- List of countries by average elevation
- Paleoclimate – Study of changes in ancient climatePages displaying short descriptions of redirect targets
References
- "Climate Change Indicators: Sea Level / Figure 1. Absolute Sea Level Change". EPA.gov. U.S. Environmental Protection Agency (EPA). July 2022. Archived from the original on 4 September 2023.
Data sources: CSIRO, 2017. NOAA, 2022.
- 27-year Sea Level Rise – TOPEX/JASON Archived 2020-11-25 at the Wayback Machine NASA Visualization Studio, 5 November 2020. This article incorporates text from this source, which is in the public domain.
- ^ Fox-Kemper, B.; Hewitt, Helene T.; Xiao, C.; Aðalgeirsdóttir, G.; Drijfhout, S. S.; Edwards, T. L.; Golledge, N. R.; Hemer, M.; Kopp, R. E.; Krinner, G.; Mix, A. (2021). Masson-Delmotte, V.; Zhai, P.; Pirani, A.; Connors, S. L.; Péan, C.; Berger, S.; Caud, N.; Chen, Y.; Goldfarb, L. (eds.). "Chapter 9: Ocean, Cryosphere and Sea Level Change" (PDF). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, US. Archived (PDF) from the original on 2022-10-24. Retrieved 2022-10-18.
- ^ "WMO annual report highlights continuous advance of climate change". World Meteorological Organization. 21 April 2023. Archived from the original on 17 December 2023. Retrieved 18 December 2023.
Press Release Number: 21042023.
- ^ IPCC, 2021: Summary for Policymakers Archived 2021-08-11 at the Wayback Machine. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Archived 2023-05-26 at the Wayback Machine Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.). Cambridge University Press, Cambridge, UK and New York, US, pp. 3−32, doi:10.1017/9781009157896.001.
- ^ WCRP Global Sea Level Budget Group (2018). "Global sea-level budget 1993–present". Earth System Science Data. 10 (3): 1551–1590. Bibcode:2018ESSD...10.1551W. doi:10.5194/essd-10-1551-2018. hdl:20.500.11850/287786.
This corresponds to a mean sea-level rise of about 7.5 cm over the whole altimetry period. More importantly, the GMSL curve shows a net acceleration, estimated to be at 0.08mm/yr.
- ^ National Academies of Sciences, Engineering, and Medicine (2011). "Synopsis". Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia. Washington, DC: The National Academies Press. p. 5. doi:10.17226/12877. ISBN 978-0-309-15176-4. Archived from the original on 2023-06-30. Retrieved 2022-04-11.
Box SYN-1: Sustained warming could lead to severe impacts
- Bindoff, N. L.; Willebrand, J.; Artale, V.; Cazenave, A.; Gregory, J.; Gulev, S.; Hanawa, K.; Le Quéré, C.; Levitus, S.; Nojiri, Y.; Shum, C. K.; Talley, L. D.; Unnikrishnan, A. (2007). "Observations: Ocean Climate Change and Sea Level: §5.5.1: Introductory Remarks". In Solomon, S.; Qin, D.; Manning, M.; Chen, Z.; Marquis, M.; Averyt, K. B.; Tignor, M.; Miller, H. L. (eds.). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. ISBN 978-0-521-88009-1. Archived from the original on 20 June 2017. Retrieved 25 January 2017.
- ^ TAR Climate Change 2001: The Scientific Basis (PDF) (Report). International Panel on Climate Change, Cambridge University Press. 2001. ISBN 0521-80767-0. Archived (PDF) from the original on 5 December 2021. Retrieved 23 July 2021.
- ^ Holder, Josh; Kommenda, Niko; Watts, Jonathan (3 November 2017). "The three-degree world: cities that will be drowned by global warming". The Guardian. Archived from the original on 2020-01-03. Retrieved 2018-12-28.
- ^ Kulp, Scott A.; Strauss, Benjamin H. (29 October 2019). "New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding". Nature Communications. 10 (1): 4844. Bibcode:2019NatCo..10.4844K. doi:10.1038/s41467-019-12808-z. PMC 6820795. PMID 31664024.
- Choi, Charles Q. (27 June 2012). "Sea Levels Rising Fast on U.S. East Coast". National Oceanic and Atmospheric Administration. Archived from the original on May 4, 2021. Retrieved October 22, 2022.
- ^ "2022 Sea Level Rise Technical Report". oceanservice.noaa.gov. Archived from the original on 2022-11-29. Retrieved 2022-07-04.
- ^ Shaw, R., Y. Luo, T. S. Cheong, S. Abdul Halim, S. Chaturvedi, M. Hashizume, G. E. Insarov, Y. Ishikawa, M. Jafari, A. Kitoh, J. Pulhin, C. Singh, K. Vasant, and Z. Zhang, 2022: Chapter 10: Asia Archived 2023-04-12 at the Wayback Machine. In Climate Change 2022: Impacts, Adaptation and Vulnerability Archived 2022-02-28 at the Wayback Machine . Cambridge University Press, Cambridge, UK and New York, US, pp. 1457–1579. doi:10.1017/9781009325844.012.
- Mimura, Nobuo (2013). "Sea-level rise caused by climate change and its implications for society". Proceedings of the Japan Academy. Series B, Physical and Biological Sciences. 89 (7): 281–301. Bibcode:2013PJAB...89..281M. doi:10.2183/pjab.89.281. ISSN 0386-2208. PMC 3758961. PMID 23883609.
- Mycoo, M., M. Wairiu, D. Campbell, V. Duvat, Y. Golbuu, S. Maharaj, J. Nalau, P. Nunn, J. Pinnegar, and O. Warrick, 2022: Chapter 15: Small islands Archived 2023-06-30 at the Wayback Machine. In Climate Change 2022: Impacts, Adaptation and Vulnerability Archived 2022-02-28 at the Wayback Machine . Cambridge University Press, Cambridge, UK and New York, US, pp. 2043–2121. doi:10.1017/9781009325844.017.
- "IPCC's New Estimates for Increased Sea-Level Rise". Yale University Press. 2013. Archived from the original on 2020-03-28. Retrieved 2015-09-01.
- ^ Thomsen, Dana C.; Smith, Timothy F.; Keys, Noni (2012). "Adaptation or Manipulation? Unpacking Climate Change Response Strategies". Ecology and Society. 17 (3). doi:10.5751/es-04953-170320. hdl:10535/8585. JSTOR 26269087.
- Slater, Thomas; Lawrence, Isobel R.; Otosaka, Inès N.; Shepherd, Andrew; et al. (25 January 2021). "Review article: Earth's ice imbalance". The Cryosphere. 15 (1): 233–246. Bibcode:2021TCry...15..233S. doi:10.5194/tc-15-233-2021. hdl:20.500.11820/df343a4d-6b66-4eae-ac3f-f5a35bdeef04. ISSN 1994-0416. S2CID 234098716. Archived from the original on 26 January 2021. Retrieved 26 January 2021. Fig. 4.
- Katsman, Caroline A.; Sterl, A.; Beersma, J. J.; van den Brink, H. W.; Church, J. A.; Hazeleger, W.; Kopp, R. E.; Kroon, D.; Kwadijk, J. (2011). "Exploring high-end scenarios for local sea level rise to develop flood protection strategies for a low-lying delta—the Netherlands as an example". Climatic Change. 109 (3–4): 617–645. Bibcode:2011ClCh..109..617K. doi:10.1007/s10584-011-0037-5. ISSN 0165-0009. S2CID 2242594.
- ^ Church, J. A.; Clark, P. U. (2013). "Sea Level Change". In Stocker, T. F.; et al. (eds.). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK and New York, US: Cambridge University Press. Archived from the original on 2020-05-09. Retrieved 2018-08-12.
- ^ Slangen, A. B. A.; Haasnoot, M.; Winter, G. (30 March 2022). "Rethinking Sea-Level Projections Using Families and Timing Differences" (PDF). Earth's Future. 10 (4): e2021EF002576. Bibcode:2022EaFut..1002576S. doi:10.1029/2021EF002576. Archived (PDF) from the original on 26 May 2024. Retrieved 28 May 2024.
- ^ Moore, John C.; Grinsted, Aslak; Zwinger, Thomas; Jevrejeva, Svetlana (10 June 2013). "Semiempirical and process-based global sea level projections". Reviews of Geophysics. 51 (3): 484–522. Bibcode:2013RvGeo..51..484M. doi:10.1002/rog.20015.
- ^ Mengel, Matthias; Levermann, Anders; Frieler, Katja; Robinson, Alexander; Marzeion, Ben; Winkelmann, Ricarda (8 March 2016). "Future sea level rise constrained by observations and long-term commitment". Proceedings of the National Academy of Sciences. 113 (10): 2597–2602. Bibcode:2016PNAS..113.2597M. doi:10.1073/pnas.1500515113. PMC 4791025. PMID 26903648.
- ^ DeConto, Robert M.; Pollard, David (30 March 2016). "Contribution of Antarctica to past and future sea-level rise". Nature. 531 (7596): 591–597. Bibcode:2016Natur.531..591D. doi:10.1038/nature17145. PMID 27029274. S2CID 205247890.
- Gillis, Justin (30 March 2016). "Climate Model Predicts West Antarctic Ice Sheet Could Melt Rapidly". The New York Times. Archived from the original on 9 June 2024. Retrieved 28 May 2024.
- "January 2017 analysis from NOAA: Global and Regional Sea Level Rise Scenarios for the United States" (PDF). Archived (PDF) from the original on 2017-12-18. Retrieved 2017-02-06.
- ^ Kopp, Robert E.; Garner, Gregory G.; Hermans, Tim H. J.; Jha, Shantenu; Kumar, Praveen; Reedy, Alexander; Slangen, Aimée B. A.; Turilli, Matteo; Edwards, Tamsin L.; Gregory, Jonathan M.; Koubbe, George; Levermann, Anders; Merzky, Andre; Nowicki, Sophie; Palmer, Matthew D.; Smith, Chris (21 December 2023). "The Framework for Assessing Changes To Sea-level (FACTS) v1.0: a platform for characterizing parametric and structural uncertainty in future global, relative, and extreme sea-level change". The Cryosphere. 16 (24): 7461–7489. Bibcode:2023GMD....16.7461K. doi:10.5194/gmd-16-7461-2023.
- ^ "The CAT Thermometer". Archived from the original on 14 April 2019. Retrieved 8 January 2023.
- "Ice sheet melt on track with 'worst-case climate scenario'". www.esa.int. Archived from the original on 9 June 2023. Retrieved 8 September 2020.
- ^ Slater, Thomas; Hogg, Anna E.; Mottram, Ruth (31 August 2020). "Ice-sheet losses track high-end sea-level rise projections". Nature Climate Change. 10 (10): 879–881. Bibcode:2020NatCC..10..879S. doi:10.1038/s41558-020-0893-y. ISSN 1758-6798. S2CID 221381924. Archived from the original on 2 September 2020. Retrieved 8 September 2020.
- Grinsted, Aslak; Christensen, Jens Hesselbjerg (2 February 2021). "The transient sensitivity of sea level rise". Ocean Science. 17 (1): 181–186. Bibcode:2021OcSci..17..181G. doi:10.5194/os-17-181-2021. hdl:11250/3135359. ISSN 1812-0784. S2CID 234353584. Archived from the original on 19 June 2022. Retrieved 3 February 2021.
- ^ Pattyn, Frank (16 July 2018). "The paradigm shift in Antarctic ice sheet modelling". Nature Communications. 9 (1): 2728. Bibcode:2018NatCo...9.2728P. doi:10.1038/s41467-018-05003-z. PMC 6048022. PMID 30013142.
- ^ Pollard, David; DeConto, Robert M.; Alley, Richard B. (February 2015). "Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure". Earth and Planetary Science Letters. 412: 112–121. Bibcode:2015E&PSL.412..112P. doi:10.1016/j.epsl.2014.12.035.
- ^ Hansen, James; Sato, Makiko; Hearty, Paul; Ruedy, Reto; Kelley, Maxwell; Masson-Delmotte, Valerie; Russell, Gary; Tselioudis, George; Cao, Junji; Rignot, Eric; Velicogna, Isabella; Tormey, Blair; Donovan, Bailey; Kandiano, Evgeniya; von Schuckmann, Karina; Kharecha, Pushker; Legrande, Allegra N.; Bauer, Michael; Lo, Kwok-Wai (22 March 2016). "Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous". Atmospheric Chemistry and Physics. 16 (6): 3761–3812. arXiv:1602.01393. Bibcode:2016ACP....16.3761H. doi:10.5194/acp-16-3761-2016. S2CID 9410444.
- ^ Zhang, Zhe (7 November 2021). Reviewing the elements of marine ice cliff instability. The International Conference on Materials Chemistry and Environmental Engineering (CONF-MCEE 2021). Journal of Physics: Conference Series. Vol. 2152. California, United States. doi:10.1088/1742-6596/2152/1/012057.
- ^ Robel, Alexander A.; Seroussi, Hélène; Roe, Gerard H. (23 July 2019). "Marine ice sheet instability amplifies and skews uncertainty in projections of future sea-level rise". Proceedings of the National Academy of Sciences. 116 (30): 14887–14892. Bibcode:2019PNAS..11614887R. doi:10.1073/pnas.1904822116. PMC 6660720. PMID 31285345.
- Pattyn, Frank (2018). "The paradigm shift in Antarctic ice sheet modelling". Nature Communications. 9 (1): 2728. Bibcode:2018NatCo...9.2728P. doi:10.1038/s41467-018-05003-z. ISSN 2041-1723. PMC 6048022. PMID 30013142.
- Dow, Christine F.; Lee, Won Sang; Greenbaum, Jamin S.; Greene, Chad A.; Blankenship, Donald D.; Poinar, Kristin; Forrest, Alexander L.; Young, Duncan A.; Zappa, Christopher J. (2018-06-01). "Basal channels drive active surface hydrology and transverse ice shelf fracture". Science Advances. 4 (6): eaao7212. Bibcode:2018SciA....4.7212D. doi:10.1126/sciadv.aao7212. ISSN 2375-2548. PMC 6007161. PMID 29928691.
- ^ Horton, Benjamin P.; Khan, Nicole S.; Cahill, Niamh; Lee, Janice S. H.; Shaw, Timothy A.; Garner, Andra J.; Kemp, Andrew C.; Engelhart, Simon E.; Rahmstorf, Stefan (2020-05-08). "Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey". npj Climate and Atmospheric Science. 3 (1): 18. Bibcode:2020npCAS...3...18H. doi:10.1038/s41612-020-0121-5. hdl:10356/143900. S2CID 218541055.
- "James Hansen's controversial sea level rise paper has now been published online". The Washington Post. 2015. Archived from the original on 2019-11-26. Retrieved 2017-09-11.
There is no doubt that the sea level rise, within the IPCC, is a very conservative number," says Greg Holland, a climate and hurricane researcher at the National Center for Atmospheric Research, who has also reviewed the Hansen study. "So the truth lies somewhere between IPCC and Jim.
- ^ Schlemm, Tanja; Feldmann, Johannes; Winkelmann, Ricarda; Levermann, Anders (24 May 2022). "Stabilizing effect of mélange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet". The Cryosphere. 16 (5): 1979–1996. Bibcode:2022TCry...16.1979S. doi:10.5194/tc-16-1979-2022.
- ^ Gilford, Daniel M.; Ashe, Erica L.; DeConto, Robert M.; Kopp, Robert E.; Pollard, David; Rovere, Alessio (5 October 2020). "Could the Last Interglacial Constrain Projections of Future Antarctic Ice Mass Loss and Sea-Level Rise?". Journal of Geophysical Research: Earth Surface. 124 (7): 1899–1918. Bibcode:2020JGRF..12505418G. doi:10.1029/2019JF005418. hdl:10278/3749063 – via American Geophysical Union.
- ^ Wise, Matthew G.; Dowdeswell, Julian A.; Jakobsson, Martin; Larter, Robert D. (October 2017). "Evidence of marine ice-cliff instability in Pine Island Bay from iceberg-keel plough marks" (PDF). Nature. 550 (7677): 506–510. Bibcode:2017Natur.550..506W. doi:10.1038/nature24458. ISSN 0028-0836. PMID 29072274. Archived from the original (PDF) on May 6, 2020.
- Clerc, Fiona; Minchew, Brent M.; Behn, Mark D. (21 October 2019). "Marine Ice Cliff Instability Mitigated by Slow Removal of Ice Shelves". Geophysical Research Letters. 50 (4): e2022GL102400. Bibcode:2019GeoRL..4612108C. doi:10.1029/2019GL084183. hdl:1912/25343. Archived from the original on 3 June 2024. Retrieved 3 June 2024 – via American Geophysical Union.
- Perkins, Sid (17 June 2021). "Collapse may not always be inevitable for marine ice cliffs". ScienceNews. Archived from the original on 23 March 2023. Retrieved 9 January 2023.
- Bassis, J. N.; Berg, B.; Crawford, A. J.; Benn, D. I. (18 June 2021). "Transition to marine ice cliff instability controlled by ice thickness gradients and velocity". Science. 372 (6548): 1342–1344. Bibcode:2021Sci...372.1342B. doi:10.1126/science.abf6271. hdl:10023/23422. ISSN 0036-8075. PMID 34140387. Archived from the original on 3 June 2024. Retrieved 3 June 2024.
- Crawford, Anna J.; Benn, Douglas I.; Todd, Joe; Åström, Jan A.; Bassis, Jeremy N.; Zwinger, Thomas (11 May 2021). "Marine ice-cliff instability modeling shows mixed-mode ice-cliff failure and yields calving rate parameterization". Nature Communications. 12 (1): 2701. Bibcode:2021NatCo..12.2701C. doi:10.1038/s41467-021-23070-7. PMC 8113328. PMID 33976208.
- ^ Dumitru, Oana A.; Dyer, Blake; Austermann, Jacqueline; Sandstrom, Michael R.; Goldstein, Steven L.; D'Andrea, William J.; Cashman, Miranda; Creel, Roger; Bolge, Louise; Raymo, Maureen E. (15 September 2023). "Last interglacial global mean sea level from high-precision U-series ages of Bahamian fossil coral reefs". Quaternary Science Reviews. 318: 108287. Bibcode:2023QSRv..31808287D. doi:10.1016/j.quascirev.2023.108287.
- Barnett, Robert L.; Austermann, Jacqueline; Dyer, Blake; Telfer, Matt W.; Barlow, Natasha L. M.; Boulton, Sarah J.; Carr, Andrew S.; Creel, Roger (15 September 2023). "Constraining the contribution of the Antarctic Ice Sheet to Last Interglacial sea level". Science Advances. 9 (27): eadf0198. Bibcode:2023SciA....9F.198B. doi:10.1126/sciadv.adf0198. PMC 10321746. PMID 37406130.
- ^ "Anticipating Future Sea Levels". EarthObservatory.NASA.gov. National Aeronautics and Space Administration (NASA). 2021. Archived from the original on 7 July 2021.
- National Research Council (2010). "7 Sea Level Rise and the Coastal Environment". Advancing the Science of Climate Change. Washington, DC: The National Academies Press. p. 245. doi:10.17226/12782. ISBN 978-0-309-14588-6. Archived from the original on 2015-08-13. Retrieved 2011-06-17.
- Hansen, J.; Russell, G.; Lacis, A.; Fung, I.; Rind, D.; Stone, P. (1985-08-30). "Climate Response Times: Dependence on Climate Sensitivity and Ocean Mixing" (PDF). Science. 229 (4716): 857–859. Bibcode:1985Sci...229..857H. doi:10.1126/science.229.4716.857. ISSN 0036-8075. PMID 17777925. Archived from the original (PDF) on March 27, 2021 – via NASA.
- Mengel, Matthias; Nauels, Alexander; Rogelj, Joeri; Schleussner, Carl-Friedrich (20 February 2018). "Committed sea-level rise under the Paris Agreement and the legacy of delayed mitigation action". Nature Communications. 9 (1): 601. Bibcode:2018NatCo...9..601M. doi:10.1038/s41467-018-02985-8. PMC 5820313. PMID 29463787.
- Bamber, Jonathan L.; Oppenheimer, Michael; Kopp, Robert E.; Aspinall, Willy P.; Cooke, Roger M. (May 2019). "Ice sheet contributions to future sea-level rise from structured expert judgment". Proceedings of the National Academy of Sciences. 116 (23): 11195–11200. Bibcode:2019PNAS..11611195B. doi:10.1073/pnas.1817205116. PMC 6561295. PMID 31110015.
- Solomon, Susan; Plattner, Gian-Kasper; Knutti, Reto; Friedlingstein, Pierre (10 February 2009). "Irreversible climate change due to carbon dioxide emissions". Proceedings of the National Academy of Sciences. 106 (6): 1704–1709. Bibcode:2009PNAS..106.1704S. doi:10.1073/pnas.0812721106. PMC 2632717. PMID 19179281.
- Pattyn, Frank; Ritz, Catherine; Hanna, Edward; Asay-Davis, Xylar; DeConto, Rob; Durand, Gaël; Favier, Lionel; Fettweis, Xavier; Goelzer, Heiko; Golledge, Nicholas R.; Kuipers Munneke, Peter; Lenaerts, Jan T. M.; Nowicki, Sophie; Payne, Antony J.; Robinson, Alexander; Seroussi, Hélène; Trusel, Luke D.; van den Broeke, Michiel (12 November 2018). "The Greenland and Antarctic ice sheets under 1.5 °C global warming" (PDF). Nature Climate Change. 8 (12): 1053–1061. Bibcode:2018NatCC...8.1053P. doi:10.1038/s41558-018-0305-8. S2CID 91886763. Archived (PDF) from the original on 7 March 2020. Retrieved 31 October 2019.
- Clark, Peter U.; Shakun, Jeremy D.; Marcott, Shaun A.; Mix, Alan C.; Eby, Michael (April 2016). "Consequences of twenty-first-century policy for multi-millennial climate and sea-level change". Nature Climate Change. 6 (4): 360–369. Bibcode:2016NatCC...6..360C. doi:10.1038/nclimate2923. ISSN 1758-6798. Archived from the original on July 11, 2020 – via Oregon State University.
- Winkelmann, Ricarda; Levermann, Anders; Ridgwell, Andy; Caldeira, Ken (11 September 2015). "Combustion of available fossil fuel resources sufficient to eliminate the Antarctic Ice Sheet". Science Advances. 1 (8): e1500589. Bibcode:2015SciA....1E0589W. doi:10.1126/sciadv.1500589. PMC 4643791. PMID 26601273.
- "2022 Sea Level Rise Technical Report". oceanservice.noaa.gov. Archived from the original on 2022-11-29. Retrieved 2022-02-22.
- Rovere, Alessio; Stocchi, Paolo; Vacchi, Matteo (2 August 2016). "Eustatic and Relative Sea Level Changes". Current Climate Change Reports. 2 (4): 221–231. Bibcode:2016CCCR....2..221R. doi:10.1007/s40641-016-0045-7. S2CID 131866367.
- "Ocean Surface Topography from Space". NASA/JPL. Archived from the original on 2011-07-22.
- "Jason-3 Satellite – Mission". www.nesdis.noaa.gov. Archived from the original on 2019-09-06. Retrieved 2018-08-22.
- Nerem, R. S.; Beckley, B. D.; Fasullo, J. T.; Hamlington, B. D.; Masters, D.; Mitchum, G. T. (27 February 2018). "Climate-change–driven accelerated sea-level rise detected in the altimeter era". Proceedings of the National Academy of Sciences of the United States of America. 115 (9): 2022–2025. Bibcode:2018PNAS..115.2022N. doi:10.1073/pnas.1717312115. PMC 5834701. PMID 29440401.
- Merrifield, Mark A.; Thompson, Philip R.; Lander, Mark (July 2012). "Multidecadal sea level anomalies and trends in the western tropical Pacific". Geophysical Research Letters. 39 (13): n/a. Bibcode:2012GeoRL..3913602M. doi:10.1029/2012gl052032. S2CID 128907116.
- Mantua, Nathan J.; Hare, Steven R.; Zhang, Yuan; Wallace, John M.; Francis, Robert C. (June 1997). "A Pacific Interdecadal Climate Oscillation with Impacts on Salmon Production". Bulletin of the American Meteorological Society. 78 (6): 1069–1079. Bibcode:1997BAMS...78.1069M. doi:10.1175/1520-0477(1997)078<1069:APICOW>2.0.CO;2.
- Lindsey, Rebecca (2019) Climate Change: Global Sea Level Archived 2019-02-28 at the Wayback Machine NOAA Climate, 19 November 2019.
- ^ Rhein, Monika; Rintoul, Stephan (2013). "Observations: Ocean" (PDF). IPCC AR5 WGI. New York: Cambridge University Press. p. 285. Archived from the original (PDF) on 2018-06-13. Retrieved 2018-08-26.
- "Other Long Records not in the PSMSL Data Set". PSMSL. Archived from the original on 20 April 2020. Retrieved 11 May 2015.
- Hunter, John; R. Coleman; D. Pugh (2003). "The Sea Level at Port Arthur, Tasmania, from 1841 to the Present". Geophysical Research Letters. 30 (7): 1401. Bibcode:2003GeoRL..30.1401H. doi:10.1029/2002GL016813. S2CID 55384210.
- Church, J.A.; White, N.J. (2006). "20th century acceleration in global sea-level rise". Geophysical Research Letters. 33 (1): L01602. Bibcode:2006GeoRL..33.1602C. CiteSeerX 10.1.1.192.1792. doi:10.1029/2005GL024826. S2CID 129887186.
- "Historical sea level changes: Last decades". www.cmar.csiro.au. Archived from the original on 2020-03-18. Retrieved 2018-08-26.
- Neil, White. "Historical Sea Level Changes". CSIRO. Archived from the original on 13 May 2020. Retrieved 25 April 2013.
- "Global and European sea level rise". European Environment Agency. 18 November 2021. Archived from the original on 27 August 2023. Retrieved 10 October 2022.
- "Scientists discover evidence for past high-level sea rise". phys.org. 2019-08-30. Archived from the original on 2019-12-13. Retrieved 2019-09-07.
- "Present CO2 levels caused 20-metre-sea-level rise in the past". Royal Netherlands Institute for Sea Research. Archived from the original on 2020-08-01. Retrieved 2020-02-03.
- Lambeck, Kurt; Rouby, Hélène; Purcell, Anthony; Sun, Yiying; Sambridge, Malcolm (28 October 2014). "Sea level and global ice volumes from the Last Glacial Maximum to the Holocene". Proceedings of the National Academy of Sciences of the United States of America. 111 (43): 15296–15303. Bibcode:2014PNAS..11115296L. doi:10.1073/pnas.1411762111. PMC 4217469. PMID 25313072.
- ^ Trisos, C. H., I. O. Adelekan, E. Totin, A. Ayanlade, J. Efitre, A. Gemeda, K. Kalaba, C. Lennard, C. Masao, Y. Mgaya, G. Ngaruiya, D. Olago, N. P. Simpson, and S. Zakieldeen 2022: Chapter 9: Africa Archived 2022-12-06 at the Wayback Machine. In Climate Change 2022: Impacts, Adaptation and Vulnerability Archived 2022-02-28 at the Wayback Machine . Cambridge University Press, Cambridge, UK and New York, US, pp. 2043–2121 doi:10.1017/9781009325844.011.
- ^ IMBIE team (13 June 2018). "Mass balance of the Antarctic Ice Sheet from 1992 to 2017". Nature. 558 (7709): 219–222. Bibcode:2018Natur.558..219I. doi:10.1038/s41586-018-0179-y. hdl:2268/225208. PMID 29899482. S2CID 49188002.
- ^ Rignot, Eric; Mouginot, Jérémie; Scheuchl, Bernd; van den Broeke, Michiel; van Wessem, Melchior J.; Morlighem, Mathieu (22 January 2019). "Four decades of Antarctic Ice Sheet mass balance from 1979–2017". Proceedings of the National Academy of Sciences. 116 (4): 1095–1103. Bibcode:2019PNAS..116.1095R. doi:10.1073/pnas.1812883116. PMC 6347714. PMID 30642972.
- ^ Zwally, H. Jay; Robbins, John W.; Luthcke, Scott B.; Loomis, Bryant D.; Rémy, Frédérique (29 March 2021). "Mass balance of the Antarctic ice sheet 1992–2016: reconciling results from GRACE gravimetry with ICESat, ERS1/2 and Envisat altimetry". Journal of Glaciology. 67 (263): 533–559. Bibcode:2021JGlac..67..533Z. doi:10.1017/jog.2021.8.
Although their methods of interpolation or extrapolation for areas with unobserved output velocities have an insufficient description for the evaluation of associated errors, such errors in previous results (Rignot and others, 2008) caused large overestimates of the mass losses as detailed in Zwally and Giovinetto (Zwally and Giovinetto, 2011).
- "How would sea level change if all glaciers melted?". United States Geological Survey. Archived from the original on 31 July 2023. Retrieved 15 January 2024.
- ^ Armstrong McKay, David; Abrams, Jesse; Winkelmann, Ricarda; Sakschewski, Boris; Loriani, Sina; Fetzer, Ingo; Cornell, Sarah; Rockström, Johan; Staal, Arie; Lenton, Timothy (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points". Science. 377 (6611): eabn7950. doi:10.1126/science.abn7950. hdl:10871/131584. ISSN 0036-8075. PMID 36074831. S2CID 252161375. Archived from the original on 14 November 2022. Retrieved 23 October 2022.
- ^ Armstrong McKay, David (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points – paper explainer". climatetippingpoints.info. Archived from the original on 18 July 2023. Retrieved 2 October 2022.
- Top 700 meters: Lindsey, Rebecca; Dahlman, Luann (6 September 2023). "Climate Change: Ocean Heat Content". climate.gov. National Oceanic and Atmospheric Administration (NOAA). Archived from the original on 29 October 2023. ● Top 2000 meters: "Ocean Warming / Latest Measurement: December 2022 / 345 (± 2) zettajoules since 1955". NASA.gov. National Aeronautics and Space Administration. Archived from the original on 20 October 2023.
- Cheng, Lijing; Foster, Grant; Hausfather, Zeke; Trenberth, Kevin E.; Abraham, John (2022). "Improved Quantification of the Rate of Ocean Warming". Journal of Climate. 35 (14): 4827–4840. Bibcode:2022JCli...35.4827C. doi:10.1175/JCLI-D-21-0895.1.
- Levitus, S.; Boyer, T.; Antonov, J. (2005). "Warming of the world ocean: 1955–2003". Geophysical Research Letters. 32 (2). Bibcode:2005GeoRL..32.2604L. doi:10.1029/2004GL021592.
- Upton, John (2016-01-19). "Deep Ocean Waters Are Trapping Vast Stores of Heat". Scientific American. Archived from the original on 2020-06-30. Retrieved 2019-02-01.
- Kuhlbrodt, T; Gregory, J.M. (2012). "Ocean heat uptake and its consequences for the magnitude of sea level rise and climate change" (PDF). Geophysical Research Letters. 39 (18): L18608. Bibcode:2012GeoRL..3918608K. doi:10.1029/2012GL052952. S2CID 19120823. Archived (PDF) from the original on 2020-07-31. Retrieved 2019-10-31.
- "Antarctic Factsheet". British Antarctic Survey. Archived from the original on 15 January 2024. Retrieved 15 January 2024.
- ^ NASA (7 July 2023). "Antarctic Ice Mass Loss 2002-2023". Archived from the original on 18 January 2024. Retrieved 15 January 2024.
- Shepherd, Andrew; Ivins, Erik; et al. (IMBIE team) (2012). "A Reconciled Estimate of Ice-Sheet Mass Balance". Science. 338 (6111): 1183–1189. Bibcode:2012Sci...338.1183S. doi:10.1126/science.1228102. hdl:2060/20140006608. PMID 23197528. S2CID 32653236. Archived from the original on 2023-01-23. Retrieved 2020-11-10.
- Scott K. Johnson (2018-06-13). "Latest estimate shows how much Antarctic ice has fallen into the sea". Ars Technica. Archived from the original on 2018-06-15. Retrieved 2018-06-15.
- ^ Greene, Chad A.; Young, Duncan A.; Gwyther, David E.; Galton-Fenzi, Benjamin K.; Blankenship, Donald D. (6 September 2018). "Seasonal dynamics of Totten Ice Shelf controlled by sea ice buttressing". The Cryosphere. 12 (9): 2869–2882. Bibcode:2018TCry...12.2869G. doi:10.5194/tc-12-2869-2018.
- ^ "Antarctica ice melt has accelerated by 280% in the last 4 decades". CNN. 14 January 2019. Archived from the original on 30 June 2020. Retrieved January 14, 2019.
Melting is taking place in the most vulnerable parts of Antarctica ... parts that hold the potential for multiple metres of sea level rise in the coming century or two
- Edwards, Tamsin L.; Nowicki, Sophie; Marzeion, Ben; Hock, Regine; et al. (5 May 2021). "Projected land ice contributions to twenty-first-century sea level rise". Nature. 593 (7857): 74–82. Bibcode:2021Natur.593...74E. doi:10.1038/s41586-021-03302-y. hdl:1874/412157. ISSN 0028-0836. PMID 33953415. S2CID 233871029. Archived from the original on 11 May 2021. Alt URL https://eprints.whiterose.ac.uk/173870/ Archived 2023-03-22 at the Wayback Machine
- Fretwell, P.; Pritchard, H. D.; Vaughan, D. G.; Bamber, J. L.; Barrand, N. E.; Bell, R.; Bianchi, C.; Bingham, R. G.; Blankenship, D. D.; Casassa, G.; Catania, G.; Callens, D.; Conway, H.; Cook, A. J.; Corr, H. F. J.; Damaske, D.; Damm, V.; Ferraccioli, F.; Forsberg, R.; Fujita, S.; Gim, Y.; Gogineni, P.; Griggs, J. A.; Hindmarsh, R. C. A.; Holmlund, P.; Holt, J. W.; Jacobel, R. W.; Jenkins, A.; Jokat, W.; Jordan, T.; King, E. C.; Kohler, J.; Krabill, W.; Riger-Kusk, M.; Langley, K. A.; Leitchenkov, G.; Leuschen, C.; Luyendyk, B. P.; Matsuoka, K.; Mouginot, J.; Nitsche, F. O.; Nogi, Y.; Nost, O. A.; Popov, S. V.; Rignot, E.; Rippin, D. M.; Rivera, A.; Roberts, J.; Ross, N.; Siegert, M. J.; Smith, A. M.; Steinhage, D.; Studinger, M.; Sun, B.; Tinto, B. K.; Welch, B. C.; Wilson, D.; Young, D. A.; Xiangbin, C.; Zirizzotti, A. (28 February 2013). "Bedmap2: improved ice bed, surface and thickness datasets for Antarctica". The Cryosphere. 7 (1): 375–393. Bibcode:2013TCry....7..375F. doi:10.5194/tc-7-375-2013. hdl:1808/18763.
- Singh, Hansi A.; Polvani, Lorenzo M. (10 January 2020). "Low Antarctic continental climate sensitivity due to high ice sheet orography". npj Climate and Atmospheric Science. 3 (1): 39. Bibcode:2020npCAS...3...39S. doi:10.1038/s41612-020-00143-w. S2CID 222179485.
- King, M. A.; Bingham, R. J.; Moore, P.; Whitehouse, P. L.; Bentley, M. J.; Milne, G. A. (2012). "Lower satellite-gravimetry estimates of Antarctic sea-level contribution". Nature. 491 (7425): 586–589. Bibcode:2012Natur.491..586K. doi:10.1038/nature11621. PMID 23086145. S2CID 4414976.
- Chen, J. L.; Wilson, C. R.; Blankenship, D.; Tapley, B. D. (2009). "Accelerated Antarctic ice loss from satellite gravity measurements". Nature Geoscience. 2 (12): 859. Bibcode:2009NatGe...2..859C. doi:10.1038/ngeo694. S2CID 130927366.
- Brancato, V.; Rignot, E.; Milillo, P.; Morlighem, M.; Mouginot, J.; An, L.; Scheuchl, B.; Jeong, S.; Rizzoli, P.; Bueso Bello, J.L.; Prats-Iraola, P. (2020). "Grounding line retreat of Denman Glacier, East Antarctica, measured with COSMO-SkyMed radar interferometry data". Geophysical Research Letters. 47 (7): e2019GL086291. Bibcode:2020GeoRL..4786291B. doi:10.1029/2019GL086291. ISSN 0094-8276.
- Amos, Jonathan (2020-03-23). "Climate change: Earth's deepest ice canyon vulnerable to melting". BBC. Archived from the original on 2024-01-13. Retrieved 2024-01-13.
- Greene, Chad A.; Blankenship, Donald D.; Gwyther, David E.; Silvano, Alessandro; van Wijk, Esmee (1 November 2017). "Wind causes Totten Ice Shelf melt and acceleration". Science Advances. 3 (11): e1701681. Bibcode:2017SciA....3E1681G. doi:10.1126/sciadv.1701681. PMC 5665591. PMID 29109976.
- Roberts, Jason; Galton-Fenzi, Benjamin K.; Paolo, Fernando S.; Donnelly, Claire; Gwyther, David E.; Padman, Laurie; Young, Duncan; Warner, Roland; Greenbaum, Jamin; Fricker, Helen A.; Payne, Antony J.; Cornford, Stephen; Le Brocq, Anne; van Ommen, Tas; Blankenship, Don; Siegert, Martin J. (2018). "Ocean forced variability of Totten Glacier mass loss". Geological Society, London, Special Publications. 461 (1): 175–186. Bibcode:2018GSLSP.461..175R. doi:10.1144/sp461.6. hdl:10871/28918. S2CID 55567382.
- Greenbaum, J. S.; Blankenship, D. D.; Young, D. A.; Richter, T. G.; Roberts, J. L.; Aitken, A. R. A.; Legresy, B.; Schroeder, D. M.; Warner, R. C.; van Ommen, T. D.; Siegert, M. J. (16 March 2015). "Ocean access to a cavity beneath Totten Glacier in East Antarctica". Nature Geoscience. 8 (4): 294–298. Bibcode:2015NatGe...8..294G. doi:10.1038/ngeo2388.
- Pan, Linda; Powell, Evelyn M.; Latychev, Konstantin; Mitrovica, Jerry X.; Creveling, Jessica R.; Gomez, Natalya; Hoggard, Mark J.; Clark, Peter U. (30 April 2021). "Rapid postglacial rebound amplifies global sea level rise following West Antarctic Ice Sheet collapse". Science Advances. 7 (18). Bibcode:2021SciA....7.7787P. doi:10.1126/sciadv.abf7787. PMC 8087405. PMID 33931453.
- ^ Garbe, Julius; Albrecht, Torsten; Levermann, Anders; Donges, Jonathan F.; Winkelmann, Ricarda (2020). "The hysteresis of the Antarctic Ice Sheet". Nature. 585 (7826): 538–544. Bibcode:2020Natur.585..538G. doi:10.1038/s41586-020-2727-5. PMID 32968257. S2CID 221885420. Archived from the original on 2023-08-19. Retrieved 2022-10-23.
- Ludescher, Josef; Bunde, Armin; Franzke, Christian L. E.; Schellnhuber, Hans Joachim (16 April 2015). "Long-term persistence enhances uncertainty about anthropogenic warming of Antarctica". Climate Dynamics. 46 (1–2): 263–271. Bibcode:2016ClDy...46..263L. doi:10.1007/s00382-015-2582-5. S2CID 131723421.
- Rignot, Eric; Bamber, Jonathan L.; van den Broeke, Michiel R.; Davis, Curt; Li, Yonghong; van de Berg, Willem Jan; van Meijgaard, Erik (13 January 2008). "Recent Antarctic ice mass loss from radar interferometry and regional climate modelling". Nature Geoscience. 1 (2): 106–110. Bibcode:2008NatGe...1..106R. doi:10.1038/ngeo102. S2CID 784105. Archived from the original on 2 March 2020. Retrieved 11 December 2019.
- ^ Voosen, Paul (13 December 2021). "Ice shelf holding back keystone Antarctic glacier within years of failure". Science Magazine. Archived from the original on 2023-04-18. Retrieved 2022-10-22.
Because Thwaites sits below sea level on ground that dips away from the coast, the warm water is likely to melt its way inland, beneath the glacier itself, freeing its underbelly from bedrock. A collapse of the entire glacier, which some researchers think is only centuries away, would raise global sea level by 65 centimeters.
- Amos, Jonathan (13 December 2021). "Thwaites: Antarctic glacier heading for dramatic change". BBC News. London. Archived from the original on 22 January 2022. Retrieved December 14, 2021.
- "After Decades of Losing Ice, Antarctica Is Now Hemorrhaging It". The Atlantic. 2018. Archived from the original on 2020-03-19. Retrieved 2018-08-29.
- "Marine ice sheet instability". AntarcticGlaciers.org. 2014. Archived from the original on 2020-05-03. Retrieved 2018-08-29.
- Kaplan, Sarah (December 13, 2021). "Crucial Antarctic ice shelf could fail within five years, scientists say". The Washington Post. Washington DC. Archived from the original on August 19, 2023. Retrieved December 14, 2021.
- Golledge, Nicholas R.; Keller, Elizabeth D.; Gomez, Natalya; Naughten, Kaitlin A.; Bernales, Jorge; Trusel, Luke D.; Edwards, Tamsin L. (2019). "Global environmental consequences of twenty-first-century ice-sheet melt". Nature. 566 (7742): 65–72. Bibcode:2019Natur.566...65G. doi:10.1038/s41586-019-0889-9. ISSN 1476-4687. PMID 30728520. S2CID 59606358.
- Moorman, Ruth; Morrison, Adele K.; Hogg, Andrew McC (2020-08-01). "Thermal Responses to Antarctic Ice Shelf Melt in an Eddy-Rich Global Ocean–Sea Ice Model". Journal of Climate. 33 (15): 6599–6620. Bibcode:2020JCli...33.6599M. doi:10.1175/JCLI-D-19-0846.1. ISSN 0894-8755. S2CID 219487981.
- A. Naughten, Kaitlin; R. Holland, Paul; De Rydt, Jan (23 October 2023). "Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first century". Nature Climate Change. 13 (11): 1222–1228. Bibcode:2023NatCC..13.1222N. doi:10.1038/s41558-023-01818-x. S2CID 264476246.
- Fretwell, P.; et al. (28 February 2013). "Bedmap2: improved ice bed, surface and thickness datasets for Antarctica" (PDF). The Cryosphere. 7 (1): 390. Bibcode:2013TCry....7..375F. doi:10.5194/tc-7-375-2013. S2CID 13129041. Archived (PDF) from the original on 16 February 2020. Retrieved 6 January 2014.
- Hein, Andrew S.; Woodward, John; Marrero, Shasta M.; Dunning, Stuart A.; Steig, Eric J.; Freeman, Stewart P. H. T.; Stuart, Finlay M.; Winter, Kate; Westoby, Matthew J.; Sugden, David E. (3 February 2016). "Evidence for the stability of the West Antarctic Ice Sheet divide for 1.4 million years". Nature Communications. 7: 10325. Bibcode:2016NatCo...710325H. doi:10.1038/ncomms10325. PMC 4742792. PMID 26838462.
- Bamber, J.L.; Riva, R.E.M.; Vermeersen, B.L.A.; LeBrocq, A.M. (14 May 2009). "Reassessment of the Potential Sea-Level Rise from a Collapse of the West Antarctic Ice Sheet". Science. 324 (5929): 901–903. Bibcode:2009Sci...324..901B. doi:10.1126/science.1169335. PMID 19443778. S2CID 11083712.
- Wolovick, Michael; Moore, John; Keefer, Bowie (27 March 2023). "Feasibility of ice sheet conservation using seabed anchored curtains". PNAS Nexus. 2 (3): pgad053. doi:10.1093/pnasnexus/pgad053. PMC 10062297. PMID 37007716. Archived from the original on 6 January 2024. Retrieved 27 October 2023.
- Wolovick, Michael; Moore, John; Keefer, Bowie (27 March 2023). "The potential for stabilizing Amundsen Sea glaciers via underwater curtains". PNAS Nexus. 2 (4): pgad103. doi:10.1093/pnasnexus/pgad103. PMC 10118300. PMID 37091546. Archived from the original on 6 January 2024. Retrieved 27 October 2023.
- Sasgen, Ingo; Wouters, Bert; Gardner, Alex S.; King, Michalea D.; Tedesco, Marco; Landerer, Felix W.; Dahle, Christoph; Save, Himanshu; Fettweis, Xavier (20 August 2020). "Return to rapid ice loss in Greenland and record loss in 2019 detected by the GRACE-FO satellites". Communications Earth & Environment. 1 (1): 8. Bibcode:2020ComEE...1....8S. doi:10.1038/s43247-020-0010-1. ISSN 2662-4435. S2CID 221200001. Text and images are available under a Creative Commons Attribution 4.0 International License Archived 2017-10-16 at the Wayback Machine.
- Kjeldsen, Kristian K.; Korsgaard, Niels J.; Bjørk, Anders A.; Khan, Shfaqat A.; Box, Jason E.; Funder, Svend; Larsen, Nicolaj K.; Bamber, Jonathan L.; Colgan, William; van den Broeke, Michiel; Siggaard-Andersen, Marie-Louise; Nuth, Christopher; Schomacker, Anders; Andresen, Camilla S.; Willerslev, Eske; Kjær, Kurt H. (16 December 2015). "Spatial and temporal distribution of mass loss from the Greenland Ice Sheet since AD 1900". Nature. 528 (7582): 396–400. Bibcode:2015Natur.528..396K. doi:10.1038/nature16183. hdl:10852/50174. PMID 26672555. S2CID 4468824.
- Shepherd, Andrew; Ivins, Erik; Rignot, Eric; Smith, Ben; van den Broeke, Michiel; Velicogna, Isabella; Whitehouse, Pippa; Briggs, Kate; Joughin, Ian; Krinner, Gerhard; Nowicki, Sophie (2020-03-12). "Mass balance of the Greenland Ice Sheet from 1992 to 2018". Nature. 579 (7798): 233–239. doi:10.1038/s41586-019-1855-2. hdl:2268/242139. ISSN 1476-4687. PMID 31822019. S2CID 219146922. Archived from the original on 2022-10-23. Retrieved 2020-05-11.
- ^ Bamber, Jonathan L; Westaway, Richard M; Marzeion, Ben; Wouters, Bert (1 June 2018). "The land ice contribution to sea level during the satellite era". Environmental Research Letters. 13 (6): 063008. Bibcode:2018ERL....13f3008B. doi:10.1088/1748-9326/aac2f0. hdl:1983/58218615-dedd-43a8-a8ea-79fb83130613.
- "Greenland ice loss is at 'worse-case scenario' levels, study finds". UCI News. 2019-12-19. Archived from the original on 2020-04-03. Retrieved 2019-12-28.
- Beckmann, Johanna; Winkelmann, Ricarda (27 July 2023). "Effects of extreme melt events on ice flow and sea level rise of the Greenland Ice Sheet". The Cryosphere. 17 (7): 3083–3099. Bibcode:2023TCry...17.3083B. doi:10.5194/tc-17-3083-2023.
- Noël, B.; van de Berg, W. J; Lhermitte, S.; Wouters, B.; Machguth, H.; Howat, I.; Citterio, M.; Moholdt, G.; Lenaerts, J. T. M.; van den Broeke, M. R. (31 March 2017). "A tipping point in refreezing accelerates mass loss of Greenland's glaciers and ice caps". Nature Communications. 8 (1): 14730. Bibcode:2017NatCo...814730N. doi:10.1038/ncomms14730. PMC 5380968. PMID 28361871.
- "Warming Greenland ice sheet passes point of no return". Ohio State University. 13 August 2020. Archived from the original on 5 September 2023. Retrieved 15 August 2020.
- King, Michalea D.; Howat, Ian M.; Candela, Salvatore G.; Noh, Myoung J.; Jeong, Seongsu; Noël, Brice P. Y.; van den Broeke, Michiel R.; Wouters, Bert; Negrete, Adelaide (13 August 2020). "Dynamic ice loss from the Greenland Ice Sheet driven by sustained glacier retreat". Communications Earth & Environment. 1 (1): 1–7. Bibcode:2020ComEE...1....1K. doi:10.1038/s43247-020-0001-2. ISSN 2662-4435. Text and images are available under a Creative Commons Attribution 4.0 International License.
- Box, Jason E.; Hubbard, Alun; Bahr, David B.; Colgan, William T.; Fettweis, Xavier; Mankoff, Kenneth D.; Wehrlé, Adrien; Noël, Brice; van den Broeke, Michiel R.; Wouters, Bert; Bjørk, Anders A.; Fausto, Robert S. (29 August 2022). "Greenland ice sheet climate disequilibrium and committed sea-level rise". Nature Climate Change. 12 (9): 808–813. Bibcode:2022NatCC..12..808B. doi:10.1038/s41558-022-01441-2. hdl:10037/26654. S2CID 251912711.
- Irvalı, Nil; Galaasen, Eirik V.; Ninnemann, Ulysses S.; Rosenthal, Yair; Born, Andreas; Kleiven, Helga (Kikki) F. (18 December 2019). "A low climate threshold for south Greenland Ice Sheet demise during the Late Pleistocene". Proceedings of the National Academy of Sciences. 117 (1): 190–195. doi:10.1073/pnas.1911902116. ISSN 0027-8424. PMC 6955352. PMID 31871153.
- Christ, Andrew J.; Bierman, Paul R.; Schaefer, Joerg M.; Dahl-Jensen, Dorthe; Steffensen, Jørgen P.; Corbett, Lee B.; Peteet, Dorothy M.; Thomas, Elizabeth K.; Steig, Eric J.; Rittenour, Tammy M.; Tison, Jean-Louis; Blard, Pierre-Henri; Perdrial, Nicolas; Dethier, David P.; Lini, Andrea; Hidy, Alan J.; Caffee, Marc W.; Southon, John (30 March 2021). "A multimillion-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century". Proceedings of the National Academy of Sciences of the United States. 118 (13): e2021442118. Bibcode:2021PNAS..11821442C. doi:10.1073/pnas.2021442118. PMC 8020747. PMID 33723012.
- Robinson, Alexander; Calov, Reinhard; Ganopolski, Andrey (11 March 2012). "Multistability and critical thresholds of the Greenland ice sheet". Nature Climate Change. 2 (6): 429–432. Bibcode:2012NatCC...2..429R. doi:10.1038/nclimate1449.
- Bochow, Nils; Poltronieri, Anna; Robinson, Alexander; Montoya, Marisa; Rypdal, Martin; Boers, Niklas (18 October 2023). "Overshooting the critical threshold for the Greenland ice sheet". Nature. 622 (7983): 528–536. Bibcode:2023Natur.622..528B. doi:10.1038/s41586-023-06503-9. PMC 10584691. PMID 37853149.
- Aschwanden, Andy; Fahnestock, Mark A.; Truffer, Martin; Brinkerhoff, Douglas J.; Hock, Regine; Khroulev, Constantine; Mottram, Ruth; Khan, S. Abbas (19 June 2019). "Contribution of the Greenland Ice Sheet to sea level over the next millennium". Science Advances. 5 (6): 218–222. Bibcode:2019SciA....5.9396A. doi:10.1126/sciadv.aav9396. PMC 6584365. PMID 31223652.
- Rounce, David R.; Hock, Regine; Maussion, Fabien; Hugonnet, Romain; et al. (5 January 2023). "Global glacier change in the 21st century: Every increase in temperature matters". Science. 379 (6627): 78–83. Bibcode:2023Sci...379...78R. doi:10.1126/science.abo1324. hdl:10852/108771. PMID 36603094. S2CID 255441012. Archived from the original on 12 January 2023. Retrieved 8 January 2023.
- Huss, Matthias; Hock, Regine (30 September 2015). "A new model for global glacier change and sea-level rise". Frontiers in Earth Science. 3: 54. Bibcode:2015FrEaS...3...54H. doi:10.3389/feart.2015.00054. hdl:20.500.11850/107708. S2CID 3256381.
- Radić, Valentina; Hock, Regine (9 January 2011). "Regionally differentiated contribution of mountain glaciers and ice caps to future sea-level rise". Nature Geoscience. 4 (2): 91–94. Bibcode:2011NatGe...4...91R. doi:10.1038/ngeo1052.
- Dyurgerov, Mark (2002). Glacier Mass Balance and Regime Measurements and Analysis, 1945-2003 (Report). doi:10.7265/N52N506F.
- Rounce, David R.; Hock, Regine; Maussion, Fabien; Hugonnet, Romain; Kochtitzky, William; Huss, Matthias; Berthier, Etienne; Brinkerhoff, Douglas; Compagno, Loris; Copland, Luke; Farinotti, Daniel; Menounos, Brian; McNabb, Robert W. (5 January 2023). "Global glacier change in the 21st century: Every increase in temperature matters". Science. 79 (6627): 78–83. Bibcode:2023Sci...379...78R. doi:10.1126/science.abo1324. hdl:10852/108771. PMID 36603094. S2CID 255441012. Archived from the original on 12 January 2023. Retrieved 8 January 2023.
- Noerdlinger, Peter D.; Brower, Kay R. (July 2007). "The melting of floating ice raises the ocean level". Geophysical Journal International. 170 (1): 145–150. Bibcode:2007GeoJI.170..145N. doi:10.1111/j.1365-246X.2007.03472.x.
- Wada, Yoshihide; Reager, John T.; Chao, Benjamin F.; Wang, Jida; Lo, Min-Hui; Song, Chunqiao; Li, Yuwen; Gardner, Alex S. (15 November 2016). "Recent Changes in Land Water Storage and its Contribution to Sea Level Variations". Surveys in Geophysics. 38 (1): 131–152. doi:10.1007/s10712-016-9399-6. PMC 7115037. PMID 32269399.
- Seo, Ki-Weon; Ryu, Dongryeol; Eom, Jooyoung; Jeon, Taewhan; Kim, Jae-Seung; Youm, Kookhyoun; Chen, Jianli; Wilson, Clark R. (15 June 2023). "Drift of Earth's Pole Confirms Groundwater Depletion as a Significant Contributor to Global Sea Level Rise 1993–2010". Geophysical Research Letters. 50 (12): e2023GL103509. Bibcode:2023GeoRL..5003509S. doi:10.1029/2023GL103509. hdl:10397/109234. S2CID 259275991.
- Sweet, William V.; Dusek, Greg; Obeysekera, Jayantha; Marra, John J. (February 2018). "Patterns and Projections of High Tide Flooding Along the U.S. Coastline Using a Common Impact Threshold" (PDF). tidesandcurrents.NOAA.gov. National Oceanic and Atmospheric Administration (NOAA). p. 4. Archived (PDF) from the original on 15 October 2022.
Fig. 2b
- Flavelle, Christopher (22 October 2024). "America's Flooding Problem". The New York Times. Archived from the original on 22 October 2024.
- Wu, Tao (October 2021). "Quantifying coastal flood vulnerability for climate adaptation policy using principal component analysis". Ecological Indicators. 129: 108006. Bibcode:2021EcInd.12908006W. doi:10.1016/j.ecolind.2021.108006.
- Rosane, Olivia (October 30, 2019). "300 Million People Worldwide Could Suffer Yearly Flooding by 2050". Ecowatch. Archived from the original on 9 December 2019. Retrieved 31 October 2019.
- McGranahan, Gordon; Balk, Deborah; Anderson, Bridget (29 June 2016). "The rising tide: assessing the risks of climate change and human settlements in low elevation coastal zones". Environment and Urbanization. 19 (1): 17–37. doi:10.1177/0956247807076960. S2CID 154588933.
- Sengupta, Somini (13 February 2020). "A Crisis Right Now: San Francisco and Manila Face Rising Seas". The New York Times. Photographer: Chang W. Lee. Archived from the original on 7 May 2020. Retrieved 4 March 2020.
- Storer, Rhi (2021-06-29). "Up to 410 million people at risk from sea level rises – study". The Guardian. Archived from the original on 2023-05-18. Retrieved 2021-07-01.
- Hooijer, A.; Vernimmen, R. (2021-06-29). "Global LiDAR land elevation data reveal greatest sea-level rise vulnerability in the tropics". Nature Communications. 12 (1): 3592. Bibcode:2021NatCo..12.3592H. doi:10.1038/s41467-021-23810-9. ISSN 2041-1723. PMC 8242013. PMID 34188026.
- Carrington, Damian (14 February 2023). "Rising seas threaten 'mass exodus on a biblical scale', UN chief warns". The Guardian. Archived from the original on 2023-07-06. Retrieved 2023-02-25.
- Xia, Wenyi; Lindsey, Robin (October 2021). "Port adaptation to climate change and capacity investments under uncertainty". Transportation Research Part B: Methodological. 152: 180–204. Bibcode:2021TRPB..152..180X. doi:10.1016/j.trb.2021.08.009. S2CID 239647501. Archived from the original on 2023-01-02. Retrieved 2021-12-17.
- "Chapter 4: Sea Level Rise and Implications for Low-Lying Islands, Coasts and Communities — Special Report on the Ocean and Cryosphere in a Changing Climate". Archived from the original on 2023-09-02. Retrieved 2021-12-17.
- ^ Michaelson, Ruth (25 August 2018). "Houses claimed by the canal: life on Egypt's climate change frontline". The Guardian. Archived from the original on 1 August 2020. Retrieved 30 August 2018.
- ^ Nagothu, Udaya Sekhar (2017-01-18). "Food security threatened by sea-level rise". Nibio. Archived from the original on 2020-07-31. Retrieved 2018-10-21.
- "Sea Level Rise". National Geographic. January 13, 2017. Archived from the original on January 17, 2017.
- "Ghost forests are eerie evidence of rising seas". Grist.org. 18 September 2016. Archived from the original on 2023-03-29. Retrieved 2017-05-17.
- "How Rising Seas Are Killing Southern U.S. Woodlands - Yale E360". e360.yale.edu. Archived from the original on 2023-08-19. Retrieved 2017-05-17.
- Rivas, Marga L.; Rodríguez-Caballero, Emilio; Esteban, Nicole; Carpio, Antonio J.; Barrera-Vilarmau, Barbara; Fuentes, Mariana M. P. B.; Robertson, Katharine; Azanza, Julia; León, Yolanda; Ortega, Zaida (2023-04-20). "Uncertain future for global sea turtle populations in face of sea level rise". Scientific Reports. 13 (1): 5277. Bibcode:2023NatSR..13.5277R. doi:10.1038/s41598-023-31467-1. ISSN 2045-2322. PMC 10119306. PMID 37081050.
- Smith, Lauren (2016-06-15). "Extinct: Bramble Cay melomys". Australian Geographic. Archived from the original on 2020-08-17. Retrieved 2016-06-17.
- Hannam, Peter (2019-02-19). "'Our little brown rat': first climate change-caused mammal extinction". The Sydney Morning Herald. Archived from the original on 2020-06-17. Retrieved 2019-06-25.
- "Sea level rise poses a major threat to coastal ecosystems and the biota they support". birdlife.org. Birdlife International. 2015. Archived from the original on 2019-05-20. Retrieved 2018-09-06.
- Pontee, Nigel (November 2013). "Defining coastal squeeze: A discussion". Ocean & Coastal Management. 84: 204–207. Bibcode:2013OCM....84..204P. doi:10.1016/j.ocecoaman.2013.07.010.
- "Mangroves - Northland Regional Council". www.nrc.govt.nz. Archived from the original on 2023-06-02. Retrieved 2020-10-28.
- Kumara, M. P.; Jayatissa, L. P.; Krauss, K. W.; Phillips, D. H.; Huxham, M. (2010). "High mangrove density enhances surface accretion, surface elevation change, and tree survival in coastal areas susceptible to sea-level rise". Oecologia. 164 (2): 545–553. Bibcode:2010Oecol.164..545K. doi:10.1007/s00442-010-1705-2. JSTOR 40864709. PMID 20593198. S2CID 6929383.
- Krauss, Ken W.; McKee, Karen L.; Lovelock, Catherine E.; Cahoon, Donald R.; Saintilan, Neil; Reef, Ruth; Chen, Luzhen (April 2014). "How mangrove forests adjust to rising sea level". New Phytologist. 202 (1): 19–34. Bibcode:2014NewPh.202...19K. doi:10.1111/nph.12605. PMID 24251960. Archived from the original on 2020-08-06. Retrieved 2019-10-31.
- Soares, M.L.G. (2009). "A Conceptual Model for the Responses of Mangrove Forests to Sea Level Rise". Journal of Coastal Research: 267–271. JSTOR 25737579.
- Crosby, Sarah C.; Sax, Dov F.; Palmer, Megan E.; Booth, Harriet S.; Deegan, Linda A.; Bertness, Mark D.; Leslie, Heather M. (November 2016). "Salt marsh persistence is threatened by predicted sea-level rise". Estuarine, Coastal and Shelf Science. 181: 93–99. Bibcode:2016ECSS..181...93C. doi:10.1016/j.ecss.2016.08.018.
- Spalding, M.; McIvor, A.; Tonneijck, F.H.; Tol, S.; van Eijk, P. (2014). "Mangroves for coastal defence. Guidelines for coastal managers & policy makers" (PDF). Wetlands International and The Nature Conservancy. Archived (PDF) from the original on 2019-11-12. Retrieved 2018-09-07.
- Weston, Nathaniel B. (16 July 2013). "Declining Sediments and Rising Seas: an Unfortunate Convergence for Tidal Wetlands". Estuaries and Coasts. 37 (1): 1–23. doi:10.1007/s12237-013-9654-8. S2CID 128615335.
- Wong, Poh Poh; Losado, I.J.; Gattuso, J.-P.; Hinkel, Jochen (2014). "Coastal Systems and Low-Lying Areas" (PDF). Climate Change 2014: Impacts, Adaptation, and Vulnerability. New York: Cambridge University Press. Archived from the original (PDF) on 2018-11-23. Retrieved 2018-10-07.
- Ohenhen, Leonard O.; Shirzaei, Manoochehr; Ojha, Chandrakanta; Kirwan, Matthew L. (11 April 2023). "Hidden vulnerability of US Atlantic coast to sea-level rise due to vertical land motion". Nature Communications. 14 (1): 2038. Bibcode:2023NatCo..14.2038O. doi:10.1038/s41467-023-37853-7. PMC 10090057. PMID 37041168.
- Rovere, Alessio; Stocchi, Paolo; Vacchi, Matteo (2 August 2016). "Eustatic and Relative Sea Level Changes". Current Climate Change Reports. 2 (4): 221–231. Bibcode:2016CCCR....2..221R. doi:10.1007/s40641-016-0045-7. S2CID 131866367.
- "Why the U.S. East Coast could be a major 'hotspot' for rising seas". The Washington Post. 2016. Archived from the original on 2020-03-31. Retrieved 2016-02-04.
- Yin, Jianjun & Griffies, Stephen (March 25, 2015). "Extreme sea level rise event linked to AMOC downturn". CLIVAR. Archived from the original on January 27, 2023. Retrieved November 23, 2021.
- Tessler, Z. D.; Vörösmarty, C. J.; Grossberg, M.; Gladkova, I.; Aizenman, H.; Syvitski, J. P. M.; Foufoula-Georgiou, E. (2015-08-07). "Profiling risk and sustainability in coastal deltas of the world" (PDF). Science. 349 (6248): 638–643. Bibcode:2015Sci...349..638T. doi:10.1126/science.aab3574. ISSN 0036-8075. PMID 26250684. S2CID 12295500. Archived (PDF) from the original on 2018-07-24. Retrieved 2019-09-02.
- ^ Bucx, Tom (2010). Comparative assessment of the vulnerability and resilience of 10 deltas: synthesis report. Delft, Netherlands: Deltares. ISBN 978-94-90070-39-7. OCLC 768078077.
- Cazenave, Anny; Nicholls, Robert J. (2010). "Sea-Level Rise and Its Impact on Coastal Zones". Science. 328 (5985): 1517–1520. Bibcode:2010Sci...328.1517N. doi:10.1126/science.1185782. ISSN 0036-8075. PMID 20558707. S2CID 199393735.
- Cooley, S., D. Schoeman, L. Bopp, P. Boyd, S. Donner, D.Y. Ghebrehiwet, S.-I. Ito, W. Kiessling, P. Martinetto, E. Ojea, M.-F. Racault, B. Rost, and M. Skern-Mauritzen, 2022: Ocean and Coastal Ecosystems and their Services (Chapter 3) Archived 2023-07-12 at the Wayback Machine. In: Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change . Cambridge University Press. In Press. - Cross-Chapter Box SLR: Sea Level Rise
- Dasgupta, Susmita; Wheeler, David; Bandyopadhyay, Sunando; Ghosh, Santadas; Roy, Utpal (February 2022). "Coastal dilemma: Climate change, public assistance and population displacement". World Development. 150: 105707. doi:10.1016/j.worlddev.2021.105707. ISSN 0305-750X. S2CID 244585347. Archived from the original on 2022-11-10. Retrieved 2021-12-17.
- "Climate Adaptation and Sea Level Rise". US EPA, Climate Change Adaptation Resource Center (ARC-X). 2 May 2016. Archived from the original on 8 May 2020. Retrieved 13 March 2020.
- ^ Fletcher, Cameron (2013). "Costs and coasts: an empirical assessment of physical and institutional climate adaptation pathways". Apo. Archived from the original on 2020-07-31. Retrieved 2019-10-31.
- Sovacool, Benjamin K. (2011). "Hard and soft paths for climate change adaptation" (PDF). Climate Policy. 11 (4): 1177–1183. Bibcode:2011CliPo..11.1177S. doi:10.1080/14693062.2011.579315. S2CID 153384574. Archived from the original (PDF) on 2020-07-10. Retrieved 2018-09-02.
- "Coastal cities face rising risk of flood losses, study says". Phys.org. 18 August 2013. Archived from the original on 22 April 2023. Retrieved 17 April 2023.
- Hallegatte, Stephane; Green, Colin; Nicholls, Robert J.; Corfee-Morlot, Jan (18 August 2013). "Future flood losses in major coastal cities". Nature Climate Change. 3 (9): 802–806. Bibcode:2013NatCC...3..802H. doi:10.1038/nclimate1979. Archived from the original on 26 August 2023. Retrieved 17 April 2023.
- Bachner, Gabriel; Lincke, Daniel; Hinkel, Jochen (29 September 2022). "The macroeconomic effects of adapting to high-end sea-level rise via protection and migration". Nature Communications. 13 (1): 5705. Bibcode:2022NatCo..13.5705B. doi:10.1038/s41467-022-33043-z. PMC 9522673. PMID 36175422.
- ^ van der Hurk, Bart; Bisaro, Alexander; Haasnoot, Marjolijn; Nicholls, Robert J.; Rehdanz, Katrin; Stuparu, Dana (28 January 2022). "Living with sea-level rise in North-West Europe: Science-policy challenges across scales". Climate Risk Management. 35: 100403. Bibcode:2022CliRM..3500403V. doi:10.1016/j.crm.2022.100403. S2CID 246354121.
- Hirschfeld, Daniella; Behar, David; Nicholls, Robert J.; Cahill, Niamh; James, Thomas; Horton, Benjamin P.; Portman, Michelle E.; Bell, Rob; Campo, Matthew; Esteban, Miguel; Goble, Bronwyn; Rahman, Munsur; Appeaning Addo, Kwasi; Chundeli, Faiz Ahmed; Aunger, Monique; Babitsky, Orly; Beal, Anders; Boyle, Ray; Fang, Jiayi; Gohar, Amir; Hanson, Susan; Karamesines, Saul; Kim, M. J.; Lohmann, Hilary; McInnes, Kathy; Mimura, Nobuo; Ramsay, Doug; Wenger, Landis; Yokoki, Hiromune (3 April 2023). "Global survey shows planners use widely varying sea-level rise projections for coastal adaptation". Communications Earth & Environment. 4 (1): 102. Bibcode:2023ComEE...4..102H. doi:10.1038/s43247-023-00703-x. PMC 11041751. PMID 38665203. Text and images are available under a Creative Commons Attribution 4.0 International License.
- Garner, Andra J.; Sosa, Sarah E.; Tan, Fangyi; Tan, Christabel Wan Jie; Garner, Gregory G.; Horton, Benjamin P. (23 January 2023). "Evaluating Knowledge Gaps in Sea-Level Rise Assessments From the United States". Earth's Future. 11 (2): e2022EF003187. Bibcode:2023EaFut..1103187G. doi:10.1029/2022EF003187. S2CID 256227421.
- McLeman, Robert (2018). "Migration and displacement risks due to mean sea-level rise". Bulletin of the Atomic Scientists. 74 (3): 148–154. Bibcode:2018BuAtS..74c.148M. doi:10.1080/00963402.2018.1461951. ISSN 0096-3402. S2CID 150179939.
- De Lellis, Pietro; Marín, Manuel Ruiz; Porfiri, Maurizio (29 March 2021). "Modeling Human Migration Under Environmental Change: A Case Study of the Effect of Sea Level Rise in Bangladesh". Earth's Future. 9 (4): e2020EF001931. Bibcode:2021EaFut...901931D. doi:10.1029/2020EF001931. hdl:10317/13078. S2CID 233626963. Archived from the original on 27 October 2022. Retrieved 27 October 2022.
- "Potential Impacts of Sea-Level Rise on Populations and Agriculture". www.fao.org. Archived from the original on 2020-04-18. Retrieved 2018-10-21.
- Erkens, G.; Bucx, T.; Dam, R.; de Lange, G.; Lambert, J. (2015-11-12). "Sinking coastal cities". Proceedings of the International Association of Hydrological Sciences. 372: 189–198. Bibcode:2015PIAHS.372..189E. doi:10.5194/piahs-372-189-2015. ISSN 2199-899X. Archived from the original on 2023-03-11. Retrieved 2021-02-03.
- Abidin, Hasanuddin Z.; Andreas, Heri; Gumilar, Irwan; Fukuda, Yoichi; Pohan, Yusuf E.; Deguchi, T. (11 June 2011). "Land subsidence of Jakarta (Indonesia) and its relation with urban development". Natural Hazards. 59 (3): 1753–1771. Bibcode:2011NatHa..59.1753A. doi:10.1007/s11069-011-9866-9. S2CID 129557182.
- Englander, John (3 May 2019). "As seas rise, Indonesia is moving its capital city. Other cities should take note". The Washington Post. Archived from the original on 13 May 2020. Retrieved 31 August 2019.
- Lawrence, J., B. Mackey, F. Chiew, M.J. Costello, K. Hennessy, N. Lansbury, U.B. Nidumolu, G. Pecl, L. Rickards, N. Tapper, A. Woodward, and A. Wreford, 2022: Chapter 11: Australasia Archived 2023-03-14 at the Wayback Machine. In Climate Change 2022: Impacts, Adaptation and Vulnerability Archived 2022-02-28 at the Wayback Machine . Cambridge University Press, Cambridge, UK and New York, US, pp. 1581–1688, |doi=10.1017/9781009325844.013
- Castellanos, E., M.F. Lemos, L. Astigarraga, N. Chacón, N. Cuvi, C. Huggel, L. Miranda, M. Moncassim Vale, J.P. Ometto, P.L. Peri, J.C. Postigo, L. Ramajo, L. Roco, and M. Rusticucci, 2022: Chapter 12: Central and South America Archived 2023-03-20 at the Wayback Machine. In Climate Change 2022: Impacts, Adaptation and Vulnerability Archived 2022-02-28 at the Wayback Machine . Cambridge University Press, Cambridge, UK and New York, US, pp. 1689–1816 doi:10.1017/9781009325844.014
- Ballesteros, Caridad; Jiménez, José A.; Valdemoro, Herminia I.; Bosom, Eva (7 September 2017). "Erosion consequences on beach functions along the Maresme coast (NW Mediterranean, Spain)". Natural Hazards. 90: 173–195. doi:10.1007/s11069-017-3038-5. hdl:2117/114541. S2CID 135328414.
- Ietto, Fabio; Cantasano, Nicola; Pellicone, Gaetano (11 April 2018). "A New Coastal Erosion Risk Assessment Indicator: Application to the Calabria Tyrrhenian Littoral (Southern Italy)". Environmental Processes. 5 (2): 201–223. Bibcode:2018EProc...5..201I. doi:10.1007/s40710-018-0295-6. S2CID 134889581. Archived from the original on 22 April 2023. Retrieved 17 April 2023.
- Ferreira, A. M.; Coelho, C.; Narra, P. (13 October 2020). "Coastal erosion risk assessment to discuss mitigation strategies: Barra-Vagueira, Portugal". Natural Hazards. 105: 1069–1107. doi:10.1007/s11069-020-04349-2. S2CID 222318289. Archived from the original on 21 April 2023. Retrieved 17 April 2023.
- Rivero, Ofelia Yocasta; Margheritini, Lucia; Frigaard, Peter (4 February 2021). "Accumulated effects of chronic, acute and man-induced erosion in Nørlev strand on the Danish west coast". Journal of Coastal Conservation. 25 (1): 24. Bibcode:2021JCC....25...24R. doi:10.1007/s11852-021-00812-9. S2CID 231794192.
- Tierolf, Lars; Haer, Toon Haer; Wouter Botzen, W. J.; de Bruijn, Jens A.; Ton, Marijn J.; Reimann, Lena; Aerts, Jeroen C. J. H. (13 March 2023). "A coupled agent-based model for France for simulating adaptation and migration decisions under future coastal flood risk". Scientific Reports. 13 (1): 4176. Bibcode:2023NatSR..13.4176T. doi:10.1038/s41598-023-31351-y. PMC 10011601. PMID 36914726.
- Calma, Justine (November 14, 2019). "Venice's historic flooding blamed on human failure and climate change". The Verge. Archived from the original on 1 August 2020. Retrieved 17 November 2019.
- Shepherd, Marshall (16 November 2019). "Venice Flooding Reveals A Real Hoax About Climate Change - Framing It As "Either/Or"". Forbes. Archived from the original on 2 May 2020. Retrieved 17 November 2019.
- Howard, Tom; Palmer, Matthew D; Bricheno, Lucy M (18 September 2019). "Contributions to 21st century projections of extreme sea-level change around the UK". Environmental Research Communications. 1 (9): 095002. Bibcode:2019ERCom...1i5002H. doi:10.1088/2515-7620/ab42d7. S2CID 203120550. Archived from the original on 21 April 2023. Retrieved 17 April 2023.
- Kimmelman, Michael; Haner, Josh (2017-06-15). "The Dutch Have Solutions to Rising Seas. The World Is Watching". The New York Times. ISSN 0362-4331. Retrieved 2019-02-02.
- "Dutch draw up drastic measures to defend coast against rising seas". The New York Times. 3 September 2008. Archived from the original on 21 August 2017. Retrieved 25 February 2017.
- "Rising Sea Levels Threaten Netherlands". National Post. Toronto. Agence France-Presse. September 4, 2008. p. AL12. Archived from the original on 28 October 2022. Retrieved 28 October 2022.
- "Florida Coastal Flooding Maps: Residents Deny Predicted Risks to Their Property". EcoWatch. 2020-02-10. Archived from the original on 2023-06-04. Retrieved 2021-01-31.
- Sweet & Park (2015). "Increased nuisance flooding along the coasts of the United States due to sea level rise: Past and future". Geophysical Research Letters. 42 (22): 9846–9852. Bibcode:2015GeoRL..42.9846M. doi:10.1002/2015GL066072. S2CID 19624347.
- "High Tide Flooding". NOAA. Archived from the original on 19 August 2023. Retrieved 10 July 2023.
- "Climate Change, Sea Level Rise Spurring Beach Erosion". Climate Central. 2012. Archived from the original on 2020-08-06. Retrieved 2018-08-20.
- Carpenter, Adam T. (2020-05-04). "Public priorities on locally-driven sea level rise planning on the East Coast of the United States". PeerJ. 8: e9044. doi:10.7717/peerj.9044. ISSN 2167-8359. PMC 7204830. PMID 32411525.
- Jasechko, Scott J.; Perrone, Debra; Seybold, Hansjörg; Fan, Ying; Kirchner, James W. (26 June 2020). "Groundwater level observations in 250,000 coastal US wells reveal scope of potential seawater intrusion". Nature Communications. 11 (1): 3229. Bibcode:2020NatCo..11.3229J. doi:10.1038/s41467-020-17038-2. PMC 7319989. PMID 32591535.
- ^ Hicke, J.A., S. Lucatello, L.D., Mortsch, J. Dawson, M. Domínguez Aguilar, C.A.F. Enquist, E.A. Gilmore, D.S. Gutzler, S. Harper, K. Holsman, E.B. Jewett, T.A. Kohler, and KA. Miller, 2022: Chapter 14: North America Archived 2023-03-20 at the Wayback Machine. In Climate Change 2022: Impacts, Adaptation and Vulnerability Archived 2022-02-28 at the Wayback Machine . Cambridge University Press, Cambridge, UK and New York, US, pp. 1929–2042
- Strauss, Benjamin H.; Orton, Philip M.; Bittermann, Klaus; Buchanan, Maya K.; Gilford, Daniel M.; Kopp, Robert E.; Kulp, Scott; Massey, Chris; Moel, Hans de; Vinogradov, Sergey (18 May 2021). "Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change". Nature Communications. 12 (1): 2720. Bibcode:2021NatCo..12.2720S. doi:10.1038/s41467-021-22838-1. PMC 8131618. PMID 34006886. S2CID 234783225.
- Seabrook, Victoria (19 May 2021). "Climate change to blame for $8 billion of Hurricane Sandy losses, study finds". Nature Communications. Sky News. Archived from the original on 9 July 2023. Retrieved 9 July 2023.
- "U.S Coastline to See Up to a Foot of Sea Level by 2050". National Oceanic and Atmospheric Administration. 15 February 2022. Archived from the original on 5 July 2023. Retrieved February 16, 2022.
- "More Damaging Flooding, 2022 Sea Level Rise Technical Report". National Ocean Service, NOAA. 2022. Archived from the original on 2022-11-29. Retrieved 2022-03-18.
- Gornitz, Vivien (2002). "Impact of Sea Level Rise in the New York City Metropolitan Area" (PDF). Global and Planetary Change. Archived from the original (PDF) on 2019-09-26. Retrieved 2020-08-09.
- "Many Low-Lying Atoll Islands Will Be Uninhabitable by Mid-21st Century | U.S. Geological Survey". www.usgs.gov. Archived from the original on 2023-06-06. Retrieved 2021-12-17.
- Zhu, Bozhong; Bai, Yan; He, Xianqiang; Chen, Xiaoyan; Li, Teng; Gong, Fang (2021-09-18). "Long-Term Changes in the Land–Ocean Ecological Environment in Small Island Countries in the South Pacific: A Fiji Vision". Remote Sensing. 13 (18): 3740. Bibcode:2021RemS...13.3740Z. doi:10.3390/rs13183740. ISSN 2072-4292.
- Sly, Peter D; Vilcins, Dwan (November 2021). "Climate impacts on air quality and child health and wellbeing: Implications for Oceania". Journal of Paediatrics and Child Health. 57 (11): 1805–1810. doi:10.1111/jpc.15650. ISSN 1034-4810. PMID 34792251. S2CID 244271480. Archived from the original on 2023-01-23. Retrieved 2021-12-17.
- Megan Angelo (1 May 2009). "Honey, I Sunk the Maldives: Environmental changes could wipe out some of the world's most well-known travel destinations". Archived from the original on 17 July 2012. Retrieved 29 September 2009.
- Kristina Stefanova (19 April 2009). "Climate refugees in Pacific flee rising sea". The Washington Times. Archived from the original on 18 October 2017. Retrieved 29 September 2009.
- Klein, Alice. "Five Pacific islands vanish from sight as sea levels rise". New Scientist. Archived from the original on 2020-03-31. Retrieved 2016-05-09.
- Simon Albert; Javier X Leon; Alistair R Grinham; John A Church; Badin R Gibbes; Colin D Woodroffe (1 May 2016). "Interactions between sea-level rise and wave exposure on reef island dynamics in the Solomon Islands". Environmental Research Letters. 11 (5): 054011. doi:10.1088/1748-9326/11/5/054011. ISSN 1748-9326. Wikidata Q29028186.
- Nurse, Leonard A.; McLean, Roger (2014). "29: Small Islands" (PDF). In Barros, VR; Field (eds.). AR5 WGII. Cambridge University Press. Archived from the original (PDF) on 2018-04-30. Retrieved 2018-09-02.
- ^ Grecequet, Martina; Noble, Ian; Hellmann, Jessica (2017-11-16). "Many small island nations can adapt to climate change with global support". The Conversation. Archived from the original on 2020-05-27. Retrieved 2019-02-02.
- Nations, United. "Small Islands, Rising Seas". United Nations. Archived from the original on 2023-05-06. Retrieved 2021-12-17.
- Caramel, Laurence (July 1, 2014). "Besieged by the rising tides of climate change, Kiribati buys land in Fiji". The Guardian. Archived from the original on 13 November 2022. Retrieved 9 January 2023.
- Long, Maebh (2018). "Vanua in the Anthropocene: Relationality and Sea Level Rise in Fiji". Symplokē. 26 (1–2): 51–70. doi:10.5250/symploke.26.1-2.0051. S2CID 150286287. Archived from the original on 2019-07-28. Retrieved 2019-10-04.
- "Adaptation to Sea Level Rise". UN Environment. 2018-01-11. Archived from the original on 2020-08-07. Retrieved 2019-02-02.
- Thomas, Adelle; Baptiste, April; Martyr-Koller, Rosanne; Pringle, Patrick; Rhiney, Kevon (2020-10-17). "Climate Change and Small Island Developing States". Annual Review of Environment and Resources. 45 (1): 1–27. doi:10.1146/annurev-environ-012320-083355. ISSN 1543-5938.
External links
- Vital signs / Sea level (NASA)
- Sea level change / Observations from space (NASA; links to multiple measurements)
- Fourth National Climate Assessment (2017) Sea Level Rise Key Message (US government agencies)
- Fifth National Climate Assessment (2023) Coastal Effects Chapter
- The Global Sea Level Observing System (GLOSS)
- USA Sea Level Rise Viewer (NOAA)
- USA Sea Level Calculator (NOAA)
- "Surging Seas in a Warming World: The latest science on present-day impacts and future projections of sea-level rise" (PDF). United Nations. 26 August 2024. Archived (PDF) from the original on 20 October 2024.
Sea level rise by country | |
---|---|
Global catastrophic risks | |||||
---|---|---|---|---|---|
Technological | |||||
Sociological | |||||
Ecological |
| ||||
Biological |
| ||||
Astronomical | |||||
Eschatological | |||||
Others |
| ||||
Fictional | |||||
Organizations | |||||
General | |||||