((short description|none))
((For|effects of changes in climate prior to the Industrial Revolution|Historical climatology))
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((Use dmy dates|date=July 2022))
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| image1            = 062821Yreka Fire CalFire -2wiki.jpg
| alt1              = Thick orange-brown smoke blocks half a blue sky, with conifers in the foreground
| image2            = Bleachedcoral.jpg
| alt2              = A few grey fish swim over grey coral with white spikes
| image3            = Village Telly in Mali.jpg
| alt3              = Desert sand half covers a village of small flat-roofed houses with scattered green trees
| image4            = US Navy 071120-M-8966H-005 An aerial view over southern Bangladesh reveals extensive flooding as a result of Cyclone Sidr.jpg
| alt4              = large areas of still water behind riverside buildings
| footer            = Some climate change effects: [[wildfire]] caused by heat and dryness, [[Coral bleaching|bleached coral]] caused by ocean acidification and heating, [[environmental migration]] caused by [[desertification]], and [[coastal flooding]] caused by [[storm]]s and sea level rise.
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<!--Please do not change the content in the lead section without first proposing the change on the talk page, and please limit overall length to under 500 words.-->
'''Effects of climate change''' are well documented and growing for  Earth's [[natural environment]] and human societies. Changes to the [[climate system]] include an [[Instrumental temperature record|overall warming trend]], [[Effects of climate change on the water cycle|changes to precipitation patterns]], and more [[extreme weather]]. As the [[Climate change|climate changes]] it impacts the natural environment with effects such as more intense [[forest fires]], thawing [[permafrost]], and [[desertification]]. These changes impact ecosystems and societies, and can become irreversible once [[Tipping points in the climate system|tipping points]] are crossed. 

<!-- this para is about physical impacts -->
The effects of climate change vary in timing and location. Up until now the [[polar amplification|Arctic has warmed faster]] than most other regions due to [[climate change feedbacks]].<ref name=":17">((Cite web |last1=Lindsey |first1=Rebecca |last2=Dahlman |first2=Luann |date=June 28, 2022 |title=Climate Change: Global Temperature |url=http://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature |url-status=live |archive-url=https://web.archive.org/web/20220917101830/https://www.climate.gov/news-features/understanding-climate/climate-change-global-temperature |archive-date=September 17, 2022 |website=climate.gov |publisher=National Oceanic and Atmospheric Administration))</ref> Surface air temperatures over land have also increased at about twice the rate they do over the ocean, causing intense [[heat waves]]. These temperatures would stabilize if [[greenhouse gas emissions]] were [[climate change mitigation|brought under control]]. [[Ice sheets]] and oceans absorb the vast majority of excess heat in the atmosphere, delaying effects there but causing them to accelerate and then continue after surface temperatures stabilize. [[Sea level rise]] is a particular long term concern as a result. The [[Effects of climate change on oceans|effects of ocean warming]] also include [[Marine heatwave|marine heatwaves]], [[ocean stratification]], [[Ocean deoxygenation|deoxygenation]], and changes to [[ocean currents]].<ref name=":26">((Citation |title=Summary for Policymakers |date=2022 |work=The Ocean and Cryosphere in a Changing Climate: Special Report of the Intergovernmental Panel on Climate Change |pages=3–36 |editor-last=Intergovernmental Panel on Climate Change (IPCC) |url=https://www.cambridge.org/core/books/ocean-and-cryosphere-in-a-changing-climate/summary-for-policymakers/097A895553D86981DFE6195ADFD3DDA4 |access-date=2023-04-24 |place=Cambridge |publisher=Cambridge University Press |doi=10.1017/9781009157964.001 |isbn=978-1-009-15796-4 |doi-access=free))</ref>((rp|10)) The [[Ocean acidification|ocean is also acidifying]] as it absorbs carbon dioxide from the atmosphere.<ref>((Cite journal |last1=Doney |first1=Scott C. |last2=Busch |first2=D. Shallin |last3=Cooley |first3=Sarah R. |last4=Kroeker |first4=Kristy J. |date=2020-10-17 |title=The Impacts of Ocean Acidification on Marine Ecosystems and Reliant Human Communities |journal=Annual Review of Environment and Resources |language=en |volume=45 |issue=1 |pages=83–112 |doi=10.1146/annurev-environ-012320-083019 |issn=1543-5938 |s2cid=225741986 |doi-access=free))</ref>  
[[File:20200118 Global warming and climate change - vertical block diagram - causes effects feedback.svg |thumb|right|upright=1.5| The primary [[causes of climate change|causes]]<ref name=NASA_2019>((cite web |title=The Causes of Climate Change |url=https://climate.nasa.gov/causes/ |url-status=live |archive-url=https://web.archive.org/web/20191221010331/https://climate.nasa.gov/causes/ |archive-date=2019-12-21 |website=climate.nasa.gov |publisher=NASA |ref=((harvid | NASA: The Causes of Climate Change | 2019))))</ref> and the wide-ranging impacts<ref name=NCA4_2017_a>((cite web |title=Climate Science Special Report / Fourth National Climate Assessment (NCA4), Volume I |url=https://science2017.globalchange.gov/ |url-status=live |archive-url=https://web.archive.org/web/20191214141932/https://science2017.globalchange.gov/ |archive-date=2019-12-14 |website=science2017.globalchange.gov |publisher=U.S. Global Change Research Program |ref=((harvid | NCA4: Climate Science Special Report | 2017 | volume=I))))</ref><ref name=NASAextremeWeather_20230900>((cite web |title=Extreme Weather and Climate Change |url=https://climate.nasa.gov/extreme-weather/ |website=NASA.gov |publisher=National Aeronautics and Space Administration |archive-url=https://web.archive.org/web/20231026173433/https://climate.nasa.gov/extreme-weather/ |archive-date=26 October 2023 |date=September 2023 |url-status=live))</ref><ref name=":26" />((rp|3–36)) of [[climate change]]. Some effects act as [[Climate change feedback|positive feedbacks]] that amplify climate change.<ref name=NASA_2016>((cite web |date=2016 |title=The Study of Earth as an Integrated System |url=https://climate.nasa.gov/nasa_science/science/ |url-status=live |archive-url=https://web.archive.org/web/20161102022200/https://climate.nasa.gov/nasa_science/science/ |archive-date=2016-11-02 |website=nasa.gov |publisher=NASA |ref=((harvid | NASA: The Study of Earth as an Integrated System | 2016))))
</ref>]]

<!-- this para is about land and nature impacts -->
The ecosystems most immediately threatened by climate change are in the [[Montane ecosystems|mountains]], [[coral reef]]s, and [[Climate change in the Arctic|the Arctic]]. Excess heat is causing environmental changes in those locations that exceed the ability of animals to adapt.<ref>((cite web|author=EPA|date=19 January 2017|title=Climate Impacts on Ecosystems|url=https://19january2017snapshot.epa.gov/climate-impacts/climate-impacts-ecosystems_.html#Extinction|url-status=live|archive-url=https://web.archive.org/web/20180127185656/https://19january2017snapshot.epa.gov/climate-impacts/climate-impacts-ecosystems_.html#Extinction|archive-date=27 January 2018|access-date=5 February 2019|quote=Mountain and arctic ecosystems and species are particularly sensitive to climate change... As ocean temperatures warm and the acidity of the ocean increases, bleaching and coral die-offs are likely to become more frequent.))</ref> Species are escaping heat by migrating towards the poles and to higher ground when they can.<ref name=":8" /> Sea level rise threatens coastal [[wetlands]] with [[coastal flooding|flooding]]. Decreases in [[soil moisture]] in certain locations can cause [[desertification]] and damage ecosystems like the [[Amazon Rainforest]].<ref name=":11">IPCC, 2019: [https://www.ipcc.ch/site/assets/uploads/sites/4/2022/11/SRCCL_SPM.pdf Summary for Policymakers]. In: [https://www.ipcc.ch/srccl/ Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems] [P.R. Shukla, J. Skea, E. Calvo Buendia, V. Masson-Delmotte, H.- O. Pörtner, D. C. Roberts, P. Zhai, R. Slade, S. Connors, R. van Diemen, M. Ferrat, E. Haughey, S. Luz, S. Neogi, M. Pathak, J. Petzold, J. Portugal Pereira, P. Vyas, E. Huntley, K. Kissick, M. Belkacemi, J. Malley, (eds.)]. ((doi|10.1017/9781009157988.001))</ref>((rp|9)) At ((Convert|2|C-change)) of warming, around 10% of species on land would become critically endangered.<ref name=":1">((cite book |last1=Parmesan |first1=Camille |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Morecroft |first2=Mike |last3=Trisurat |first3=Yongyut |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |page= |chapter=Chapter 2: Terrestrial and Freshwater Ecosystems and their Services |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter02.pdf))</ref>((rp|259))

<!-- this para is about impacts on humans and society -->
Humans are [[Climate change vulnerability|vulnerable to climate change]] in many ways. Sources of [[food security|food]] and [[fresh water]] can be threatened by environmental changes. [[Effects of climate change on human health|Human health]] can be impacted by weather extremes or by ripple effects like the [[Climate change and infectious diseases|spread of infectious diseases]]. Economic impacts include changes to [[Effects of climate change on agriculture|agriculture]], [[Climate change and fisheries|fisheries]], [[forestry]], and tourism. Outdoor labor may not be possible many more days out of the year due to [[Occupational heat stress|heat stress]]. [[Effects of climate change on small island countries|Island nations]] and [[Climate change and cities|coastal cities]] may be inundated by rising sea levels. Some groups of people may be particularly at risk from climate change, such as the [[Climate change and poverty|poor]], [[Climate change and children|children]], and [[Climate change and Indigenous peoples|indigenous peoples]]. [[Industrialised countries]], which have emitted the vast majority of CO<sub>2</sub>, have more resources to adapt to global warming than developing nations do.<ref>((Cite web |last=Director |first=International |date=15 October 2018 |title=The Industries and Countries Most Vulnerable to Climate Change |url=https://internationaldirector.com/finance/the-industries-and-countries-most-vulnerable-to-climate-change/ |url-status=live |archive-url=https://web.archive.org/web/20200102154401/https://internationaldirector.com/finance/the-industries-and-countries-most-vulnerable-to-climate-change/ |archive-date=2 January 2020 |access-date=15 December 2019 |website=International Director))</ref> Cumulative effects and extreme weather events can lead to [[Climate migration|displacement and migration]].<ref>((Cite journal |last1=Kaczan |first1=David J. |last2=Orgill-Meyer |first2=Jennifer |date=2020-02-01 |title=The impact of climate change on migration: a synthesis of recent empirical insights |url=https://doi.org/10.1007/s10584-019-02560-0 |journal=Climatic Change |language=en |volume=158 |issue=3 |pages=281–300 |doi=10.1007/s10584-019-02560-0 |bibcode=2020ClCh..158..281K |s2cid=207988694 |issn=1573-1480))</ref>

((TOC limit|3))

==Changes in temperature==
((Further|Global surface temperature|Instrumental temperature record|Heat wave||))
[[File:Change in Average Temperature With Fahrenheit.svg|thumb|upright=1.35|right|Over the last 50 years the [[Arctic]] has warmed the most, and temperatures on land have generally increased more than [[sea surface temperature]]s.<ref>((Cite web |title=GISS Surface Temperature Analysis (v4) |url=https://data.giss.nasa.gov/gistemp/maps/index_v4.html |access-date=12 January 2024 |website=NASA))</ref>]]
Global warming affects all parts of Earth's [[climate system]].<ref name=":10">((Cite book|last1=Kennedy|first1=John|url=https://library.wmo.int/doc_num.php?explnum_id=5789|title=WMO statement on the State of the Global Climate in 2018|last2=Ramasamy|first2=Selvaraju|last3=Andrew|first3=Robbie|last4=Arico|first4=Salvatore|last5=Bishop|first5=Erin|last6=Braathen|first6=Geir|publisher=Chairperson, Publications Board, World Meteorological Organization|year=2019|isbn=978-92-63-11233-0|location=Geneva|page=6|access-date=24 November 2019|archive-url=https://web.archive.org/web/20191112010343/https://library.wmo.int/doc_num.php?explnum_id=5789|archive-date=12 November 2019|url-status=live))</ref> [[Global surface temperature]]s have risen by ((Convert|1.1|C-change)). Scientists say they will rise further in the future.<ref>((cite book|url=https://www.ipcc.ch/report/ar6/syr/downloads/report/IPCC_AR6_SYR_SPM.pdf|chapter=Summary for Policymakers|title=Synthesis report of the IPCC Sixth Assessment Report|year=2023|at=A1, A4))</ref><ref>((cite report|url=https://library.wmo.int/doc_num.php?explnum_id=11178|title=State of the Global Climate 2021|publisher=World Meteorological Organization|year=2022|page=2|access-date=23 April 2023|archive-date=18 May 2022|archive-url=https://web.archive.org/web/20220518083042/https://library.wmo.int/doc_num.php?explnum_id=11178|url-status=dead))</ref> The changes in climate are not uniform across the Earth. In particular, most land areas have warmed faster than most ocean areas. The [[Arctic]] is warming faster than most other regions.<ref name=":17" /> Night-time temperatures have increased faster than daytime temperatures.<ref>((cite journal |last1=Davy |first1=Richard |last2=Esau |first2=Igor |last3=Chernokulsky |first3=Alexander |last4=Outten |first4=Stephen |last5=Zilitinkevich |first5=Sergej |title=Diurnal asymmetry to the observed global warming |journal=International Journal of Climatology |date=January 2017 |volume=37 |issue=1 |pages=79–93 |doi=10.1002/joc.4688 |bibcode=2017IJCli..37...79D |doi-access=free ))</ref> The impact on nature and people depends on how much more the Earth warms.<ref name=":9">Schneider, S.H., S. Semenov, A. Patwardhan, I. Burton, C.H.D. Magadza, M. Oppenheimer, A.B. Pittock, A. Rahman, J.B. Smith, A. Suarez and F. Yamin, 2007: [https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg2-chapter19-1.pdf Chapter 19: Assessing key vulnerabilities and the risk from climate change]. [https://www.ipcc.ch/report/ar4/wg2/ Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change], M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 779-810.</ref>((rp|787))

Scientists use several methods to predict the effects of human-caused climate change. One is to investigate past natural changes in climate.<ref>((Cite web|last=Joyce|first=Christopher|date=30 August 2018|title=To Predict Effects Of Global Warming, Scientists Looked Back 20,000 Years|url=https://www.npr.org/2018/08/30/643342003/to-predict-effects-of-global-warming-scientists-looked-back-20-000-years|url-status=live|archive-url=https://web.archive.org/web/20191229182055/https://www.npr.org/2018/08/30/643342003/to-predict-effects-of-global-warming-scientists-looked-back-20-000-years|archive-date=29 December 2019|access-date=29 December 2019|website=NPR))</ref> To assess changes in Earth's [[paleoclimate|past climate]] scientists have studied [[tree rings]], [[ice core]]s, [[coral]]s, and ocean and lake [[sediment]]s.<ref name="noaa proxy climate data">((citation|author=Overpeck, J.T.|title=NOAA Paleoclimatology Global Warming – The Story: Proxy Data|date=20 August 2008|url=http://www.ncdc.noaa.gov/paleo/globalwarming/proxydata.html|archive-url=https://web.archive.org/web/20170203204629/https://www.ncdc.noaa.gov/paleo/globalwarming/proxydata.html|publisher=NOAA Paleoclimatology Program – NCDC Paleoclimatology Branch|access-date=20 November 2012|archive-date=3 February 2017|url-status=live))</ref> These show that recent temperatures have surpassed anything in the last 2,000 years.<ref name="phys.org">[https://phys.org/news/2019-07-20th-century-hottest-years.html The 20th century was the hottest in nearly 2,000 years, studies show] ((Webarchive|url=https://web.archive.org/web/20190725190643/https://phys.org/news/2019-07-20th-century-hottest-years.html|date=25 July 2019)), 25 July 2019</ref> By the end of the 21st century, temperatures may increase to a level last seen in the [[Mid-Pliocene Warm Period|mid-Pliocene]]. This was around 3 million years ago.<ref>Nicholls, R.J., P.P. Wong, V.R. Burkett, J.O. Codignotto, J.E. Hay, R.F. McLean, S. Ragoonaden and C.D. Woodroffe, 2007: [https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg2-chapter6-1.pdf Chapter 6: Coastal systems and low-lying areas]. [https://www.ipcc.ch/report/ar4/wg2/ Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change], M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 315-356.</ref>((rp|322)) At that time, mean global temperatures were about ((Convert|2|-|4|C-change)) warmer than pre-industrial temperatures. The global mean sea level was up to ((convert|25|m)) higher than it is today.<ref name=":20">Oppenheimer, M., B.C. Glavovic , J. Hinkel, R. van de Wal, A.K. Magnan, A. Abd-Elgawad, R. Cai, M. Cifuentes-Jara, R.M. DeConto, T. Ghosh, J. Hay, F. Isla, B. Marzeion, B. Meyssignac, and Z. Sebesvari, 2019: [https://www.ipcc.ch/site/assets/uploads/sites/3/2022/03/06_SROCC_Ch04_FINAL.pdf Chapter 4: Sea Level Rise and Implications for Low-Lying Islands, Coasts and Communities]. In: [https://www.ipcc.ch/srocc/ IPCC Special Report on the Ocean and Cryosphere in a Changing Climate] [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 321–445. ((doi|10.1017/9781009157964.006)).</ref>((rp|323)) The modern observed rise in temperature and ((CO2)) concentrations has been rapid. even abrupt geophysical events in Earth's history do not approach current rates.<ref>Allen, M.R., O.P. Dube, W. Solecki, F. Aragón-Durand, W. Cramer, S. Humphreys, M. Kainuma, J. Kala, N. Mahowald, Y. Mulugetta, R. Perez, M.Wairiu, and K. Zickfeld, 2018: [https://www.ipcc.ch/site/assets/uploads/sites/2/2022/06/SR15_Chapter_1_HR.pdf Chapter 1: Framing and Context]. In: [https://www.ipcc.ch/sr15/ Global Warming of 1.5&nbsp;°C. An IPCC Special Report on the impacts of global warming of 1.5&nbsp;°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty] [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 49-92. ((doi|10.1017/9781009157940.003)).</ref>((rp|54))

How much the world warms depends on [[Climate change scenario|human greenhouse gas emissions]] and on how [[climate sensitivity|sensitive the climate is to greenhouse gases]].<ref name="USGCRP exec sum">((cite book|title=Global Climate Change Impacts in the United States |editor=Thomas R. Karl |editor2=Jerry M. Melillo |editor3=Thomas C. Peterson |pages=22–24 |chapter=Global Climate Change |access-date=2 May 2013 |url=http://downloads.globalchange.gov/usimpacts/pdfs/climate-impacts-report.pdf |archive-url=https://web.archive.org/web/20191115033015/https://downloads.globalchange.gov/usimpacts/pdfs/climate-impacts-report.pdf |archive-date=15 November 2019 |url-status=live))</ref> The more carbon dioxide (((CO2))) is emitted in the 21st century the hotter the world will be by 2100. For a doubling of greenhouse gas concentrations, the global mean temperature would rise by about ((Convert|2.5|-|4|C-change)).<ref>((Cite web|date=9 August 2021|title=In-depth Q&A: The IPCC's sixth assessment report on climate science|url=https://www.carbonbrief.org/in-depth-qa-the-ipccs-sixth-assessment-report-on-climate-science|access-date=12 February 2022|website=Carbon Brief ))</ref> If emissions of ((CO2)) stopped abruptly and there was no use of [[negative emission technologies]], the Earth's climate would not start moving back to its pre-industrial state. Temperatures would stay at the same high level for several centuries. After about a thousand years, 20% to 30% of human-emitted ((CO2)) would remain in the atmosphere. The ocean and land would not have taken  them. This would commit the climate to a warmer state long after emissions have stopped.<ref>((Cite book|last1=Collins|first1=M.|title=((Harvnb|IPCC AR5 WG1|2013))|last2=Knutti|first2=R.|last3=Arblaster|first3=J. M.|last4=Dufresne|first4=J.-L.|last5=Fichefet|first5=T.|last6=Friedlingstein|first6=P.|last7=Gao|first7=X.|last8=Gutowski|first8=W. J.|last9=Johns|first9=T.|year=2013|page=1104|chapter=Chapter 12: Long-term Climate Change: Projections, Commitments and Irreversibility|ref=((harvid|IPCC AR5 WG1 Ch12|2013))|display-authors=4|access-date=3 January 2020|chapter-url=https://archive.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter12_FINAL.pdf|archive-url=https://web.archive.org/web/20191219013928/https://archive.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter12_FINAL.pdf|archive-date=19 December 2019|url-status=live|first12=C.|first13=A. J.|last13=Weaver|first14=M.|last14=Wehner|first10=G.|last11=Shongwe|first11=M.|last10=Krinner|last12=Tebaldi))</ref>

With current [[Climate change mitigation|mitigation policies]] the temperature will be about 2.7&nbsp;°C (2.0–3.6&nbsp;°C) above pre-industrial levels by 2100. It would rise by ((Convert|2.4|C-change)) if governments achieved all their unconditional pledges and targets. If all the countries that have set or are considering net-zero targets achieve them, the temperature will rise by around ((Convert|1.8|C-change)). There is a big gap between national plans and commitments and the actions that governments have taken around the world.<ref>((cite web |date=9 November 2021 |title=Temperatures |url=https://climateactiontracker.org/global/temperatures/ |archive-url=https://web.archive.org/web/20220126022845/https://climateactiontracker.org/global/temperatures/ |archive-date=26 January 2022 |work=Climate Action Tracker))</ref>

== Weather ==
The lower and middle atmosphere, where nearly all weather occurs, are heating due to the [[greenhouse effect]].<ref name="Hausfather_2017">
((cite web |last=Hausfather |first=Zeke |date=21 June 2017 |title=Study: Why troposphere warming differs between models and satellite data |url=https://www.carbonbrief.org/study-why-troposphere-warming-differs-between-models-and-satellite-data |access-date=19 November 2019 |website=Carbon Brief ))
</ref> Evaporation and atmospheric moisture content increase as temperatures rise.<ref name=":7" /> [[Water vapor|Water vapour]] is a greenhouse gas, so this process is a [[Water vapour feedback|self-reinforcing feedback]].<ref name="Royal_Society_basics">
((cite web |title=Climate change: evidence and causes ((!)) Royal Society |url=https://royalsociety.org/topics-policy/projects/climate-change-evidence-causes/basics-of-climate-change/ |access-date=19 November 2019 |website=royalsociety.org ))
</ref>

The excess water vapour also gets caught up in storms. This makes them more intense, larger, and potentially longer-lasting. This in turn causes rain and snow events to become stronger and leads to increased risk of flooding. Extra drying worsens natural dry spells and droughts. This increases risk of [[heat wave]]s and wildfires.<ref name=":7">((Cite journal |last=Trenberth |first=Ke |date=2011 |title=Changes in precipitation with climate change |journal=Climate Research |volume=47 |issue=1 |pages=123–138 |doi=10.3354/cr00953 |bibcode=2011ClRes..47..123T |doi-access=free ))</ref> Scientists have identified human activities as the cause of recent climate trends. They are now able to estimate the impact of climate change on extreme weather events. They call this process [[extreme event attribution]]. For instance such research can look at historical data for a region and conclude that a specific heat wave was more intense due to climate change.<ref>((Cite journal |last1=Swain |first1=Daniel L. |last2=Singh |first2=Deepti |last3=Touma |first3=Danielle |last4=Diffenbaugh |first4=Noah S. |date=2020-06-19 |title=Attributing Extreme Events to Climate Change: A New Frontier in a Warming World |journal=One Earth |language=en |volume=2 |issue=6 |pages=522–527 |doi=10.1016/j.oneear.2020.05.011 |bibcode=2020OEart...2..522S |s2cid=222225686 |issn=2590-3322|doi-access=free ))</ref> In addition , the time shifts of the season onsets, changes in the length of the season durations have been reported in many regions of the world.<ref>Schwartz, M.D. and Reiter, B.E. (2000) Changes in North American spring. ''International Journal of Climatology'', 20, 929–932.</ref><ref>Hekmatzadeh, A.A., Kaboli, S. and Torabi Haghighi, A. (2020) New indices for assessing changes in seasons and in timing characteristics of air temperature. ''Theoretical and Applied Climatology'', 140, 1247–1261. ((doi|10.1007/s00704-020-03156-w)).</ref><ref>Kozlov, M.V. and Berlina, N.G. (2002) Decline in the length of the summer season on the Kola Peninsula, Russia. ''Climatic Change'', 54, 387–398</ref><ref>Sparks, T.H. and Menzel, A. (2002) Observed changes in seasons: an overview. ''International Journal of Climatology'', 22, 1715–1725.</ref><ref>Aksu, H. (2022). A determination of season shifting across Turkey in the period 1965–2020. ''International Journal of Climatology'', 42(16), 8232–8247. ((doi|10.1002/joc.7705))</ref> As a result of this, the timing of the extreme weather events such as heavy precipitaions and heat waves is changing in parallel with season shifting.

=== Heat waves and temperature extremes ===
((See also|Heat wave|Effects of climate change on human health))
[[File:1951+ Percent of global area at temperature records - Seasonal comparison - NOAA.svg|thumb|upright=1.35|New high temperature records have outpaced new low temperature records on a growing portion of Earth's surface.<ref name=NOAA_October>((cite web |title=Mean Monthly Temperature Records Across the Globe / Timeseries of Global Land and Ocean Areas at Record Levels for October from 1951-2023 |url=https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202310/supplemental/page-3 |website=NCEI.NOAA.gov |publisher=National Centers for Environmental Information (NCEI) of the National Oceanic and Atmospheric Administration (NOAA)|archive-url=https://web.archive.org/web/20231116185412/https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202310/supplemental/page-3 |archive-date=16 November 2023 |date=November 2023 |url-status=live)) (change "202310" in URL to see years other than 2023, and months other than 10=October)</ref>]]
[[File:20211109 Frequency of extreme weather for different degrees of global warming - bar chart IPCC AR6 WG1 SPM.svg|thumb|upright=1.35|Large increases in both the frequency and intensity of [[extreme weather]] events (for increasing degrees of global warming) are expected.<ref name=":0">IPCC, 2021: [https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf Summary for Policymakers]. In: [https://www.ipcc.ch/report/ar6/wg1/ Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change] [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, United Kingdom and New York, NY, US, pp. 3−32, ((doi|10.1017/9781009157896.001))</ref>((rp|18))]]
[[File:Map of increasing heatwave trends over the midlatitudes and Europe.webp|thumb|upright=1.35|Map of increasing heatwave trends (frequency and cumulative intensity) over the midlatitudes and Europe, July–August 1979–2020<ref>((cite journal |last1=Rousi |first1=Efi |last2=Kornhuber |first2=Kai |last3=Beobide-Arsuaga |first3=Goratz |last4=Luo |first4=Fei |last5=Coumou |first5=Dim |title=Accelerated western European heatwave trends linked to more-persistent double jets over Eurasia |journal=Nature Communications |date=4 July 2022 |volume=13 |issue=1 |pages=3851 |doi=10.1038/s41467-022-31432-y |pmid=35788585 |pmc=9253148 |bibcode=2022NatCo..13.3851R |doi-access=free))</ref>]]

Heatwaves over land have become more frequent and more intense in almost all world regions since the 1950s, due to [[climate change]]. Heat waves are more likely to occur simultaneously with droughts. [[Marine heatwaves]] are twice as likely as they were in 1980.<ref name="IPCC6AR_ExtremeEvents2">((cite book |title=Climate Change 2021: The Physical Science Basis |publisher=Intergovernmental Panel on Climate Change |year=2021 |pages=8–10 |chapter=Summary for Policymakers |chapter-url=https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM_final.pdf |archive-url=https://web.archive.org/web/20211104175351/https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM_final.pdf |archive-date=4 November 2021 |url-status=live))</ref> Climate change will lead to more very hot days and fewer very cold days.<ref name=":6">IPCC, 2013: [https://www.climatechange2013.org/images/report/WG1AR5_SPM_FINAL.pdf Summary for Policymakers]. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, US.</ref>((rp|7)) There are fewer [[cold wave]]s.<ref name=":0" />((rp|8)) 

Experts can often attribute the intensity of individual heat waves to global warming. Some extreme events would have been nearly impossible without human influence on the climate system. A heatwave that would occur once every ten years before global warming started now occurs 2.8 times as often. Under further warming, heatwaves are set to become more frequent. An event that would occur every ten years would occur every other year if global warming reaches ((Convert|2|C-change)).<ref>((Cite journal |last1=Clarke |first1=Ben |last2=Otto |first2=Friederike |last3=Stuart-Smith |first3=Rupert |last4=Harrington |first4=Luke |date=2022-06-28 |title=Extreme weather impacts of climate change: an attribution perspective |journal=Environmental Research: Climate |volume=1 |issue=1 |pages=012001 |doi=10.1088/2752-5295/ac6e7d |issn=2752-5295 |s2cid=250134589 |doi-access=free|hdl=10044/1/97290 |hdl-access=free ))</ref>

[[Hyperthermia|Heat stress]] is related to temperature. It also increases if humidity is higher. The [[wet-bulb temperature]] measures both temperature and humidity. Humans cannot adapt to a wet-bulb temperature above ((Convert|35|C)). This heat stress can kill people. If global warming is kept below ((Convert|1.5|or|2|C-change)), it will probably be possible to avoid this deadly heat and humidity in most of the tropics. But there may still be negative health impacts.<ref>((Cite journal |last1=Zhang |first1=Yi |last2=Held |first2=Isaac |last3=Fueglistaler |first3=Stephan |date=8 March 2021 |title=Projections of tropical heat stress constrained by atmospheric dynamics |journal=Nature Geoscience |volume=14 |issue=3 |pages=133–137 |doi=10.1038/s41561-021-00695-3 |bibcode=2021NatGe..14..133Z |s2cid=232146008 |url=https://repository.library.noaa.gov/view/noaa/30706 ))</ref><ref>((Cite web |last=Milman |first=Oliver |date=8 March 2021 |title=Global heating pushes tropical regions towards limits of human livability |url=http://www.theguardian.com/science/2021/mar/08/global-heating-tropical-regions-human-livability |access-date=22 July 2022 |website=The Guardian ))</ref>

There is some evidence climate change is leading to a weakening of the [[polar vortex]]. This would make the [[jet stream]] more wavy.<ref>((Cite web|last=NOAA|date=16 February 2022|title=Understanding the Arctic polar vortex|url=https://www.climate.gov/news-features/understanding-climate/understanding-arctic-polar-vortex|access-date=19 February 2022|website=www.climate.gov ))</ref> This would lead to outbursts of very cold winter weather across parts of Eurasia<ref>((Cite web|website=Deutsche Welle|title=How global warming can cause Europe's harsh winter weather |date=11 February 2021|url=https://www.dw.com/en/cold-winter-global-warming-polar-vortex/a-56534450|access-date=15 December 2021 ))</ref> and North America and incursions of very warm air into the Arctic.<ref>((cite news|date=2 September 2021|title=Climate change: Arctic warming linked to colder winters|work=BBC News|url=https://www.bbc.com/news/science-environment-58425526|url-status=live|access-date=20 October 2021|archive-url=https://web.archive.org/web/20211020112818/https://www.bbc.com/news/science-environment-58425526|archive-date=20 October 2021))</ref><ref>((cite journal|last1=Cohen|first1=Judah|last2=Agel|first2=Laurie|last3=Barlow|first3=Mathew|last4=Garfinkel|first4=Chaim I.|last5=White|first5=Ian|date=3 September 2021|title=Linking Arctic variability and change with extreme winter weather in the United States|journal=Science|volume=373|issue=6559|pages=1116–1121|bibcode=2021Sci...373.1116C|doi=10.1126/science.abi9167|pmid=34516838 |s2cid=237402139))</ref><ref>((Cite web|last=Douglas|first=Erin|date=14 December 2021|title=Winters get warmer with climate change. So what explains Texas' cold snap in February?|url=https://www.texastribune.org/2021/12/14/winter-weather-texas-climate-change/|access-date=15 December 2021|website=The Texas Tribune ))</ref>

=== Rain ===
((Main|Effects of climate change on the water cycle))Warming increases global average [[precipitation]]. Precipitation is when water vapour condenses out of clouds, such as rain and snow.<ref name="WG 1 chapter 8"/>((rp|1057)) Higher temperatures increase evaporation and surface drying. As the air warms it can hold more water. For every degree Celsius it can hold 7% more [[water vapour]].<ref name="WG 1 chapter 8"/>((rp|1057)) Scientists have observed changes in the amount, intensity, frequency, and type of precipitation.<ref name=":22">((citation |title=In ((harvnb|IPCC SREX|2012)) |page=8 |access-date=17 December 2012 |archive-url=https://web.archive.org/web/20190627001210/https://docs.google.com/file/d/0B1gFp6Ioo3akYklZcWkwWHJud00/edit?pli=1 |url-status=live |chapter=Summary for policymakers |chapter-url=https://docs.google.com/file/d/0B1gFp6Ioo3akYklZcWkwWHJud00/edit?pli=1 |archive-date=27 June 2019))</ref> Overall, climate change is causing longer hot dry spells, broken by more intense rainfall.<ref name=":4">((Cite book |last=Trenberth |first=Kevin E. |url=https://www.cambridge.org/core/product/identifier/9781108979030/type/book |title=The Changing Flow of Energy Through the Climate System |date=2022 |publisher=Cambridge University Press |isbn=978-1-108-97903-0 |edition=1 |doi=10.1017/9781108979030 |s2cid=247134757))</ref>((rp|151, 154)) 

Climate change has increased contrasts in rainfall amounts between wet and dry seasons. Wet seasons are getting wetter and dry seasons are getting drier. In the northern [[Polar regions of Earth|high latitudes]], warming has also caused an increase in the amount of snow and rain.<ref name="WG 1 chapter 8"/>((rp|1057)) In the Southern Hemisphere, the rain associated with the [[storm track]]s has shifted south. Changes in [[monsoon]]s vary a lot. More monsoon systems are becoming wetter than drier. In Asia summer monsoons are getting wetter. The [[West African monsoon]] is getting wetter over the central [[Sahel]], and drier in the far western Sahel.<ref name="WG 1 chapter 8" />((rp|1058))

=== Extreme storms ===
[[File:Wea02630 - Flickr - NOAA Photo Library.jpg|thumb|upright=1.35 |[[New Orleans]] submerged after [[Hurricane Katrina]], September 2005]]
Storms become wetter under climate change. These include [[tropical cyclones]] and [[extratropical cyclones]]. Both the maximum and mean rainfall rates increase. This more extreme rainfall is also true for [[thunderstorm]]s in some regions.<ref name=AR6WG1CH11>((Cite book|chapter=Chapter 11: Weather and climate extreme events in a changing climate
|last1 = Seneviratne| first1 = Sonia I.| last2 = Zhang| first2 = Xuebin| last3 = Adnan| first3 = M.|chapter-url= https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter11.pdf |display-authors=etal|title= Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate|year=2021
|publisher=Cambridge University Press|page=1519))</ref> Furthermore, tropical cyclones and storm tracks are moving towards the poles. This means some regions will see large changes in maximum wind speeds.<ref name=AR6WG1CH11 /><ref name=":52">((Cite journal |last1=Knutson |first1=Thomas |last2=Camargo |first2=Suzana J. |last3=Chan |first3=Johnny C. L. |last4=Emanuel |first4=Kerry |last5=Ho |first5=Chang-Hoi |last6=Kossin |first6=James |last7=Mohapatra |first7=Mrutyunjay |last8=Satoh |first8=Masaki |last9=Sugi |first9=Masato |last10=Walsh |first10=Kevin |last11=Wu |first11=Liguang |date=August 6, 2019 |title=Tropical Cyclones and Climate Change Assessment: Part II. Projected Response to Anthropogenic Warming |journal=Bulletin of the American Meteorological Society |volume=101 |issue=3 |pages=BAMS–D–18–0194.1 |doi=10.1175/BAMS-D-18-0194.1 |bibcode=2020BAMS..101E.303K |doi-access=free ))</ref> Scientists expect there will be fewer tropical cyclones. But they expect their strength  to increase.<ref name=":52" /> There has probably been an increase in the number of tropical cyclones that intensify rapidly.<ref name=AR6WG1CH11 />  Meteorological and seismological data indicate a widespread increase in wind-driven global ocean wave energy in recent decades that has been attributed to an increase in storm intensity over the oceans due to climate change.<ref>((cite journal |last1=Reguero |first1=B. |last2=Losada |first2=I. |last3=Mendez |first3=F. |title=A recent increase in global wave power as a consequence of oceanic warming |journal=Nature Communications |date=2019 |volume=10 |issue=1 |page=205 |doi=10.1038/s41467-018-08066-0|pmid=30643133 |pmc=6331560 |bibcode=2019NatCo..10..205R ))</ref><ref>((cite journal |last1=Bromirski |first1=P. |title=Climate-Induced Decadal Ocean Wave Height Variability\ From Microseisms: 1931–2021 |journal=Journal of Geophysical Research: Oceans |date=2023 |volume=128 |issue=8 |doi=10.1029/2023JC019722|bibcode=2023JGRC..12819722B |s2cid=260414378 |doi-access=free ))</ref><ref>((cite journal |last1=Aster |first1=R. |last2=Ringler |first2=A. |last3=Anthony |first3=R. |last4=Lee |first4=T. |title=Increasing ocean wave energy observed in Earth's seismic wavefield since the late 20th century |journal=Nature Communications |date=2023 |volume=14 |issue=1 |page=6984 |doi=10.1038/s41467-023-42673-w|pmid=37914695 |pmc=10620394 |bibcode=2023NatCo..14.6984A ))</ref>

== Impacts on land ==
[[File:Soil moisture and climate change.svg|thumb|upright=1.35|The sixth IPCC Assessment Report projects changes in average soil moisture at 2.0&nbsp;°C of warming, as measured in [[standard deviation]]s from the 1850 to 1900 baseline.]]

=== Floods ===
Due to an increase in heavy rainfall events, [[floods]] are likely to become more severe when they do occur.<ref name="WG 1 chapter 8" />((rp|1155)) The interactions between rainfall and flooding are complex. There are some regions in which flooding is expected to become rarer. This depends on several factors. These include changes in rain and snowmelt, but also [[soil moisture]].<ref name="WG 1 chapter 8" />((rp|1156)) Climate change leaves soils drier in some areas, so they may absorb rainfall more quickly. This leads to less flooding. Dry soils can also become harder. In this case heavy rainfall runs off  into rivers and lakes. This increases risks of flooding.<ref name="WG 1 chapter 8" />((rp|1155))

=== Droughts ===
[[File:California Drought Dry Lakebed 2009.jpg|thumb|upright=1.35|A dry lakebed in [[droughts in California|California]]. In 2022, the state was experiencing its most serious drought in 1,200 years, worsened by climate change.<ref>((cite web |author=Irina Ivanova |date=2 June 2022 |title=California is rationing water amid its worst drought in 1,200 years |url=https://www.cbsnews.com/amp/news/water-cutbacks-california-6-million-people-drought/ |access-date=2 June 2022 |publisher=[[CBS News]]))</ref>]]Climate change affects many factors associated with [[drought]]s. These include how much rain falls and how fast the rain [[Evaporation|evaporates]] again. Warming over land increases the severity and frequency of droughts around much of the world.<ref>((Cite journal |last1=Cook |first1=Benjamin I. |last2=Mankin |first2=Justin S. |last3=Anchukaitis |first3=Kevin J. |date=2018-05-12 |title=Climate Change and Drought: From Past to Future |url=https://link.springer.com/article/10.1007/s40641-018-0093-2 |journal=Current Climate Change Reports |volume=4 |issue=2 |pages=164–179 |doi=10.1007/s40641-018-0093-2 |bibcode=2018CCCR....4..164C |s2cid=53624756 |issn=2198-6061))</ref><ref name="WG 1 chapter 8">Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, and O. Zolina, 2021: [https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter08.pdf Chapter 8: Water Cycle Changes]. In [https://www.ipcc.ch/report/ar6/wg1/ Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change] [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, United Kingdom and New York, NY, US, pp. 1055–1210, ((doi|10.1017/9781009157896.010))</ref>((rp|1057)) In some tropical and subtropical regions of the world, there will probably be less rain due to global warming. This will make them more prone to drought. Droughts are set to worsen in many regions of the world. These include Central America, the Amazon and south-western South America. They also include West and Southern Africa. The Mediterranean and south-western Australia are also some of these regions.<ref name="WG 1 chapter 8"/>((rp|1157))

Higher temperatures increase evaporation. This dries the soil and increases [[Plant stress measurement|plant stress]]. Agriculture suffers as a result. This means even regions where overall rainfall is expected to remain relatively stable will experience these impacts.<ref name="WG 1 chapter 8"/>((rp|1157)) These regions include central and northern Europe. Without climate change mitigation, around one third of land areas are likely to experience moderate or more severe drought by 2100.<ref name="WG 1 chapter 8"/>((rp|1157)) Due to global warming droughts are more frequent and intense than in the past.<ref>((Cite web |date=2023-03-13 |title=Scientists confirm global floods and droughts worsened by climate change |url=https://www.pbs.org/newshour/science/scientists-confirm-global-floods-and-droughts-worsened-by-climate-change |access-date=2023-05-01 |website=PBS NewsHour |language=en-us))</ref> 

Several impacts make their impacts worse. These are increased water demand, population growth and urban expansion in many areas.<ref>((Cite journal |last1=Mishra |first1=A. K. |last2=Singh |first2=V. P. |year=2011 |title=Drought modeling – A review |journal=Journal of Hydrology |volume=403 |issue=1–2 |pages=157–175 |bibcode=2011JHyd..403..157M |doi=10.1016/j.jhydrol.2011.03.049))</ref> [[Land restoration]] can help reduce the impact of droughts. One example of this is [[agroforestry]].<ref name=":19">Daniel Tsegai, Miriam Medel, Patrick Augenstein, Zhuojing Huang (2022) [https://www.unccd.int/resources/publications/drought-numbers Drought in Numbers 2022 - restoration for readiness and resilience], United Nations Convention to Combat Desertification (UNCCD)</ref>

=== Wildfires ===
((Further|Wildfire#Climate change effects))
[[File:1911- Wildfire disasters - worldwide.svg |thumb|upright=1.35|Wildfire disasters (those claiming at least 10 lives or affecting over 100 people) have increased substantially in recent decades.<ref name=AlJazeera_CRED_20210819/> Climate change intensifies heatwaves and droughts that dry vegetation, which in turn fuels wildfires.<ref name=AlJazeera_CRED_20210819>((cite news |last1=Haddad |first1=Mohammed |last2=Hussein |first2=Mohammed |title=Mapping wildfires around the world |url=https://www.aljazeera.com/news/2021/8/19/mapping-wildfires-around-the-world-interactive |publisher=Al Jazeera |date=19 August 2021 |archive-url=https://web.archive.org/web/20210819102412/https://www.aljazeera.com/news/2021/8/19/mapping-wildfires-around-the-world-interactive |archive-date=19 August 2021 |url-status=live )) Data source: [[Centre for Research on the Epidemiology of Disasters]].</ref>]]

Climate change promotes the type of weather that makes [[wildfire]]s more likely. In some areas, an increase of wildfires has been attributed directly to climate change. Evidence from Earth's past also shows more fire in warmer periods.<ref name=":02">((cite web |last1=Jones |first1=Matthew |last2=Smith |first2=Adam |last3=Betts |first3=Richard |last4=Canadell |first4=Josep |last5=Prentice |first5=Collin |last6=Le Quéré |first6=Corrine |title=Climate Change Increases the Risk of Wildfires |url=https://sciencebrief.org/briefs/wildfires |access-date=16 February 2022 |website=ScienceBrief))</ref> Climate change increases evaporation. This can cause vegetation to dry out. When a fire starts in an area with very dry vegetation, it can spread rapidly. Higher temperatures can also lengthen the fire season. This is the time of year in which severe wildfires are most likely, particularly in regions where snow is disappearing.<ref name=":13">((Cite web |last=Dunne |first=Daisy |date=14 July 2020 |title=Explainer: How climate change is affecting wildfires around the world |url=https://www.carbonbrief.org/explainer-how-climate-change-is-affecting-wildfires-around-the-world |access-date=17 February 2022 |website=Carbon Brief ))</ref>

Weather conditions are raising the risks of wildfires. But the total area burnt by wildfires has decreased. This is mostly because [[savanna]] has been converted to [[croplands|cropland]], so there are fewer trees to burn. [[Prescribed burning]] isan indigenous practice in the US and Australia. It can reduce wildfire burning.<ref name=":13" /> The carbon released from wildfires can add to greenhouse gas concentrations. Climate models do not yet full reflect this feedback.<ref name=":0" />((rp|20))

== Oceans ==
[[File:WhereIsTheHeatOfGlobalWarming2023.svg|thumb|upright=1.35|Oceans have taken up almost 90% of the excess heat accumulated on Earth due to global warming.<ref>((Cite journal |last1=von Schuckmann |first1=Karina |last2=Minière |first2=Audrey |last3=Gues |first3=Flora |last4=Cuesta-Valero |first4=Francisco José |last5=Kirchengast |first5=Gottfried |last6=Adusumilli |first6=Susheel |last7=Straneo |first7=Fiammetta |last8=Ablain |first8=Michaël |last9=Allan |first9=Richard P. |last10=Barker |first10=Paul M. |last11=Beltrami |first11=Hugo |last12=Blazquez |first12=Alejandro |last13=Boyer |first13=Tim |last14=Cheng |first14=Lijing |last15=Church |first15=John |date=2023-04-17 |title=Heat stored in the Earth system 1960–2020: where does the energy go? |url=https://essd.copernicus.org/articles/15/1675/2023/ |journal=Earth System Science Data |language=English |volume=15 |issue=4 |pages=1675–1709 |doi=10.5194/essd-15-1675-2023 |bibcode=2023ESSD...15.1675V |issn=1866-3508|doi-access=free|hdl=20.500.11850/619535 |hdl-access=free ))</ref>]]
[[File:Co2 time series aloha 08-09-2023.jpg|thumb|upright=1.35|Climate change causes a drop in the ocean's pH value (called [[ocean acidification]]): Time series of atmospheric ((CO2)) at Mauna Loa (in parts per million volume, ppmv; red), surface ocean p((CO2)) (μatm; blue) and surface ocean pH (green) at Ocean Station ALOHA in the subtropical North Pacific Ocean.<ref>((Cite web |title=Atmospheric ((CO2)) and Ocean pH |url=https://cleanet.org/details/images/33568.html |access-date=2022-11-17 |website=cleanet.org))</ref><ref>((Cite web |title=Quality of pH Measurements in the NODC Data Archives |url=https://www.pmel.noaa.gov/co2/story/Quality+of+pH+Measurements+in+the+NODC+Data+Archives |access-date=2023-12-18 |website=www.pmel.noaa.gov))</ref>]]((excerpt|Effects of climate change on oceans|paragraphs=1-3|file=no))

=== Sea level rise ===
[[File:1880- Global average sea level rise (SLR) - annually.svg|thumb|upright=1.35|The global average sea level has risen about ((convert|250|mm|in)) since 1880,<ref name=EPA_SLR_202207>((cite web |title=Climate Change Indicators: Sea Level / Figure 1. Absolute Sea Level Change |url=https://www.epa.gov/climate-indicators/climate-change-indicators-sea-level |website=EPA.gov |publisher=U.S. Environmental Protection Agency (EPA) |archive-url=https://web.archive.org/web/20230904035800/https://www.epa.gov/climate-indicators/climate-change-indicators-sea-level |archive-date=4 September 2023 |date=July 2022 |quote=Data sources: CSIRO, 2017. NOAA, 2022. |url-status=live ))</ref> increasing the elevation on top of which other types of flooding ([[Tidal flooding|high-tide flooding]] and [[storm surge]]) occur.]]
[[File:2050 Projected sea level rise - United States coasts - NOAA.svg|thumb|upright=1.35|Long-term sea level rise occurs in addition to intermittent tidal flooding. [[NOAA]] predicts different levels of sea level rise for coastlines within a single country.<ref name=NOAA_SeaLevelRiseTechReport_20220200>((cite web |title=2022 Sea Level Rise Technical Report |url=https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html |publisher=National Ocean Service, National Oceanic and Atmospheric Administration (NOAA) |archive-url=https://web.archive.org/web/20221129070303/https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html |archive-date=November 29, 2022 |date=February 2022 |url-status=live ))</ref>]]
((excerpt|sea level rise|paragraphs=1-2))

==Ice and snow==
((See also|Special Report on the Ocean and Cryosphere in a Changing Climate))
[[File:20210125 The Cryosphere - Floating and grounded ice - imbalance - climate change.png|thumb|upright=1.35| Earth lost 28 trillion tonnes of ice between 1994 and 2017, with melting grounded ice (ice sheets and glaciers) raising the global sea level by 34.6 ±3.1 mm.<ref name="Cryosphere_20210125" /> The rate of ice loss has risen by 57% since the 1990s−from 0.8 to 1.2 trillion tonnes per year.<ref name="Cryosphere_20210125">((cite journal |last1=Slater |first1=Thomas |last2=Lawrence |first2=Isobel R. |last3=Otosaka |first3=Inès N. |last4=Shepherd |first4=Andrew |last5=Gourmelen |first5=Noel |last6=Jakob |first6=Livia |last7=Tepes |first7=Paul |last8=Gilbert |first8=Lin |last9=Nienow |first9=Peter |title=Review article: Earth's ice imbalance |journal=The Cryosphere |date=25 January 2021 |volume=15 |issue=1 |pages=233–246 |doi=10.5194/tc-15-233-2021 |bibcode=2021TCry...15..233S |doi-access=free |hdl=20.500.11820/df343a4d-6b66-4eae-ac3f-f5a35bdeef04 |hdl-access=free )) Fig. 4.</ref>]]
[[File:2015-2100 Impacts of global warming on glaciers and sea level rise.svg|thumb|upright=1.35| Melting of glacial mass is approximately linearly related to temperature rise.<ref name="Science_20230105">((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. |display-authors=4 |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 |volume=379 |issue=6627 |pages=78–83 |bibcode=2023Sci...379...78R |doi=10.1126/science.abo1324 |pmid=36603094 |s2cid=255441012|hdl=10852/108771 |hdl-access=free ))</ref>]]
[[File:Duration of the yearly snow cover ring-width reconstruction together with modelled record for the Alps.webp|thumb|upright=1.35|Shrinkage of snow cover duration in the [[Alps]], starting ca. end of the 19th century, highlighting [[climate change adaptation]] needs<ref>((cite journal |last1=Carrer |first1=Marco |last2=Dibona |first2=Raffaella |last3=Prendin |first3=Angela Luisa |last4=Brunetti |first4=Michele |title=Recent waning snowpack in the Alps is unprecedented in the last six centuries |journal=Nature Climate Change |date=February 2023 |volume=13 |issue=2 |pages=155–160 |doi=10.1038/s41558-022-01575-3 |bibcode=2023NatCC..13..155C |language=en |issn=1758-6798|doi-access=free|hdl=11577/3477269 |hdl-access=free ))</ref>]]
The [[cryosphere]], the area of the Earth covered by snow or ice, is extremely sensitive to changes in global climate.<ref>[https://serc.carleton.edu/eslabs/cryosphere/1c.html Getting to Know the Cryosphere] ((Webarchive|url=https://web.archive.org/web/20191215212026/https://serc.carleton.edu/eslabs/cryosphere/1c.html |date=15 December 2019 )), Earth Labs</ref> There has been an extensive loss of snow on land since 1981. Some of the largest declines have been observed in the spring.<ref>((Cite journal |last1=Thackeray |first1=Chad W. |last2=Derksen |first2=Chris |last3=Fletcher |first3=Christopher G. |last4=Hall |first4=Alex |date=2019-12-01 |title=Snow and Climate: Feedbacks, Drivers, and Indices of Change |url=https://doi.org/10.1007/s40641-019-00143-w |journal=Current Climate Change Reports |language=en |volume=5 |issue=4 |pages=322–333 |doi=10.1007/s40641-019-00143-w |bibcode=2019CCCR....5..322T |s2cid=201675060 |issn=2198-6061))</ref> During the 21st century, [[snow cover]] is projected to continue its retreat in almost all regions.<ref>IPCC, 2019: [https://www.ipcc.ch/site/assets/uploads/sites/3/2022/03/02_SROCC_TS_FINAL.pdf Technical Summary] [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, E. Poloczanska, K. Mintenbeck, M. Tignor, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. In: [https://www.ipcc.ch/srocc/ IPCC Special Report on the Ocean and Cryosphere in a Changing Climate] [H.- O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 39–69. ((doi|10.1017/9781009157964.002))</ref>((rp|39–69))

===Glaciers decline===
((Further|Retreat of glaciers since 1850))
Since the beginning of the twentieth century, there has been a widespread [[Retreat of glaciers since 1850|retreat of glaciers]].<ref name=":21" />((rp|1215)) Those glaciers that are not associated with the polar [[ice sheet]]s lost around 8% of their mass between 1971 and 2019.<ref name=":21" />((rp|1275)) In the [[Andes]] in South America and in the Himalayas in Asia, the retreat of glaciers could impact water supply.<ref>((Cite journal |last1=Lee |first1=Ethan |last2=Carrivick |first2=Jonathan L. |last3=Quincey |first3=Duncan J. |last4=Cook |first4=Simon J. |last5=James |first5=William H. M. |last6=Brown |first6=Lee E. |date=2021-12-20 |title=Accelerated mass loss of Himalayan glaciers since the Little Ice Age |journal=Scientific Reports |language=en |volume=11 |issue=1 |pages=24284 |bibcode=2021NatSR..1124284L |doi=10.1038/s41598-021-03805-8 |issn=2045-2322 |pmc=8688493 |pmid=34931039))</ref><ref>((Cite book |url=https://www.worldcat.org/oclc/1085575303 |title=The Andean glacier and water atlas : the impact of glacier retreat on water resources |date=2018 |others=Tina Schoolmeester, Koen Verbist, Kari Synnøve Johansen |isbn=978-92-3-100286-1 |location=Paris, France |pages=9 |oclc=1085575303))</ref> The melting of those glaciers could also cause landslides or [[glacial lake outburst flood]]s.<ref>((Cite web |title=As Himalayan Glaciers Melt, a Water Crisis Looms in South Asia |url=https://e360.yale.edu/features/himalayas-glaciers-climate-change |access-date=2023-05-01 |website=Yale E360 |language=en-US))</ref>

=== Ice sheets decline ===
((Further|Antarctic ice sheet#Changes due to climate change|Greenland ice sheet#Recent melting))
The melting of the [[Greenland ice sheet|Greenland]] and [[West Antarctic ice sheet]]s will continue to contribute to sea level rise over long time-scales. The Greenland ice sheet loss is mainly driven by melt from the top.  Antarctic ice loss is driven by warm ocean water melting the [[outlet glacier]]s.<ref name=":21" />((rp|1215))

Future melt of the West Antarctic ice sheet is potentially abrupt under a high emission scenario, as a consequence of a partial collapse.<ref name=":27">Collins M., M. Sutherland, L. Bouwer, S.-M. Cheong, T. Frölicher, H. Jacot Des Combes, M. Koll Roxy, I. Losada, K. McInnes, B. Ratter, E. Rivera-Arriaga, R.D. Susanto, D. Swingedouw, and L. Tibig, 2019: [https://www.ipcc.ch/site/assets/uploads/sites/3/2022/03/08_SROCC_Ch06_FINAL.pdf Chapter 6: Extremes, Abrupt Changes and Managing Risk]. In: [https://www.ipcc.ch/srocc/ IPCC Special Report on the Ocean and Cryosphere in a Changing Climate] [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 589–655. ((doi|10.1017/9781009157964.008)).</ref>((rp|595–596)) Part of the ice sheet is grounded on [[bedrock]] below sea level. This makes it possibly vulnerable to the self-enhancing process of [[marine ice sheet instability]]. ''Marine ice cliff instability'' could also contribute to a partial collapse. But there is limited evidence for its importance.<ref name=":21" />((rp|1269–1270)) A partial collapse of the ice sheet would lead to rapid sea level rise and a local decrease in ocean salinity. It would be irreversible for decades and possibly even millennia.<ref name=":27" />((rp|595–596)) The complete loss of the West Antarctic ice sheet would cause over ((Convert|5|m)) of sea level rise.<ref>((Cite journal |last1=Stokes |first1=Chris R. |last2=Abram |first2=Nerilie J. |last3=Bentley |first3=Michael J. |display-authors=etal |date=August 2022 |title=Response of the East Antarctic Ice Sheet to past and future climate change |url=https://www.nature.com/articles/s41586-022-04946-0 |journal=Nature |language=en |volume=608 |issue=7922 |pages=275–286 |doi=10.1038/s41586-022-04946-0 |pmid=35948707 |bibcode=2022Natur.608..275S |s2cid=251494636 |issn=1476-4687|hdl=20.500.11820/9fe0943d-ae69-4916-a57f-13965f5f2691 |hdl-access=free ))</ref>

In contrast to the West Antarctic ice sheet, melt of the Greenland ice sheet is projected to take place more gradually over millennia.<ref name=":27" />((rp|595–596)) Sustained warming between ((Convert|1|C-change)) (low confidence) and ((Convert|4|C-change)) (medium confidence) would lead to a complete loss of the ice sheet. This would contribute ((Convert|7|m|abbr=on)) to sea levels globally.<ref name=":20" />((rp|363)) The ice loss could become irreversible due to a further self-enhancing feedback. This is called the elevation-surface mass balance feedback. When ice melts on top of the ice sheet, the elevation drops. Air temperature is higher at lower altitudes, so this promotes further melting.<ref name=":20" />((rp|362))

=== Sea ice decline ===
((Further|Arctic sea ice decline|Antarctic sea ice#Recent trends and climate change))
[[File:1978- Antarctic sea ice extent - Purich and Doddridge.png |thumb|upright=1.35 |Reporting the reduction in Antarctic sea ice extent in mid 2023, researchers concluded that a "regime shift" may be taking place "in which previously important relationships no longer dominate sea ice variability".<ref name=CommsEarthEnv_20230913>((cite journal |last1=Purich |first1=Ariaan |last2=Doddridge |first2=Edward W. |title=Record low Antarctic sea ice coverage indicates a new sea ice state |journal=Communications Earth & Environment |date=13 September 2023 |volume=4 |issue=1 |page=314 |doi=10.1038/s43247-023-00961-9 |bibcode=2023ComEE...4..314P |s2cid=261855193 |doi-access=free ))</ref>]]
[[Sea ice]] reflects 50% to 70% of the incoming solar radiation back into space. Only 6% of incoming solar energy is reflected by the ocean.<ref>((Cite web|title=Thermodynamics: Albedo ((!)) National Snow and Ice Data Center|url=https://nsidc.org/cryosphere/seaice/processes/albedo.html|url-status=dead|archive-url=https://web.archive.org/web/20171011021602/https://nsidc.org/cryosphere/seaice/processes/albedo.html|archive-date=11 October 2017|access-date=14 October 2020|website=nsidc.org))</ref> As the climate warms, the area covered by snow or sea ice decreases. After sea ice melts, more energy is absorbed by the ocean, so it warms up. This [[ice-albedo feedback]] is a self-reinforcing feedback of climate change.<ref>((cite web|url=https://oceanservice.noaa.gov/facts/sea-ice-climate.html|access-date=21 April 2023|website=NOAA|title=How does sea ice affect global climate?))</ref> Large-scale measurements of sea ice have only been possible since satellites came into use.<ref name="NOAA_2013">
((cite web
 | title=Arctic Report Card 2012
 | url=http://www.arctic.noaa.gov/reportcard/sea_ice.html
 | publisher=NOAA
 | access-date=8 May 2013 |archive-url=https://web.archive.org/web/20130217032825/http://www.arctic.noaa.gov/reportcard/sea_ice.html |archive-date=17 February 2013
))
</ref>

Sea ice in the Arctic has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. The decline of sea ice in the Arctic has been accelerating during the early twenty-first century. It has a rate of decline  of 4.7% per decade. It has declined over 50% since the first satellite records.<ref>((Cite journal |last1=Huang |first1=Yiyi |last2=Dong |first2=Xiquan |last3=Bailey |first3=David A. |last4=Holland |first4=Marika M. |author-link4=Marika Holland |last5=Xi |first5=Baike |last6=DuVivier |first6=Alice K. |last7=Kay |first7=Jennifer E. |last8=Landrum |first8=Laura L. |last9=Deng |first9=Yi |date=2019-06-19 |title=Thicker Clouds and Accelerated Arctic Sea Ice Decline: The Atmosphere-Sea Ice Interactions in Spring |journal=Geophysical Research Letters |volume=46 |issue=12 |pages=6980–6989 |bibcode=2019GeoRL..46.6980H |doi=10.1029/2019gl082791 |issn=0094-8276 |s2cid=189968828 |doi-access=free |hdl=10150/634665|hdl-access=free ))</ref><ref name=":222">((Cite journal |last1=Senftleben |first1=Daniel |last2=Lauer |first2=Axel |last3=Karpechko |first3=Alexey |date=2020-02-15 |title=Constraining Uncertainties in CMIP5 Projections of September Arctic Sea Ice Extent with Observations |journal=Journal of Climate |volume=33 |issue=4 |pages=1487–1503 |bibcode=2020JCli...33.1487S |doi=10.1175/jcli-d-19-0075.1 |issn=0894-8755 |s2cid=210273007 |doi-access=free))</ref><ref name=":32">((Cite journal |last1=Yadav |first1=Juhi |last2=Kumar |first2=Avinash |last3=Mohan |first3=Rahul |date=2020-05-21 |title=Dramatic decline of Arctic sea ice linked to global warming |url=http://dx.doi.org/10.1007/s11069-020-04064-y |journal=Natural Hazards |volume=103 |issue=2 |pages=2617–2621 |doi=10.1007/s11069-020-04064-y |bibcode=2020NatHa.103.2617Y |issn=0921-030X |s2cid=218762126))</ref> Ice-free summers are expected to be rare at ((Convert|1.5|C-change)) degrees of warming. They are set to occur at least once every decade with a warming level of ((Convert|2|C-change)).<ref>IPCC, 2018: [https://www.ipcc.ch/site/assets/uploads/sites/2/2022/06/SPM_version_report_LR.pdf Summary for Policymakers]. In: [https://www.ipcc.ch/sr15/ Global Warming of 1.5&nbsp;°C. An IPCC Special Report on the impacts of global warming of 1.5&nbsp;°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty] [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 3-24. ((doi|10.1017/9781009157940.001)).</ref>((rp|8)) The Arctic will likely become ice-free at the end of some summers before 2050.<ref name=":21">Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G. Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021: [https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf Chapter 9: Ocean, Cryosphere and Sea Level Change]. In [https://www.ipcc.ch/report/ar6/wg1/ Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change] [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, United Kingdom and New York, NY, US ((doi|10.1017/9781009157896.011))</ref>((rp|9))

Sea ice extent in Antarctica varies a lot year by year. This makes it difficult to determine a trend, and record highs and record lows have been observed between 2013 and 2023. The general trend since 1979, the start of the [[Satellite era|satellite measurements]], has been roughly flat. Between 2015 and 2023, there has been a decline in sea ice, but due to the high variability, this does not correspond to a significant trend.<ref name="NOAA2023">((Cite web |date=14 March 2023 |title=Understanding climate: Antarctic sea ice extent |url=http://www.climate.gov/news-features/understanding-climate/understanding-climate-antarctic-sea-ice-extent |access-date=2023-03-26 |website=NOAA Climate.gov |language=))</ref>

=== Permafrost thawing ===
((Further|Permafrost#Impacts of climate change|Climate change in Russia#Permafrost))

Globally, [[permafrost]] warmed by about ((val|0.3|u=degC)) between 2007 and 2016. The extent of permafrost has been falling for decades. More decline is expected in the future.<ref name=":21" />((rp|1280)) Permafrost thaw makes the ground weaker and unstable. The thaw can seriously damage human infrastructure  in permafrost areas such as railways, settlements and pipelines.<ref>((Cite book |last1=Barry |first1=Roger Graham |title=The global cryosphere past, present and future |last2=Gan |first2=Thian-Yew |date=2021 |isbn=978-1-108-48755-9 |edition=Second revised |location=Cambridge, United Kingdom |oclc=1256406954))</ref>((rp|236)) Thawing soil can also release methane and ((CO2)) from decomposing microbes. This can generate a strong [[climate change feedback|feedback loop]] to [[global warming]].<ref name="Koven 1877–1900">((Cite journal|last1=Koven|first1=Charles D.|last2=Riley|first2=William J.|last3=Stern|first3=Alex|date=2012-10-01|title=Analysis of Permafrost Thermal Dynamics and Response to Climate Change in the CMIP5 Earth System Models|journal=Journal of Climate|volume=26|issue=6|pages=1877–1900|doi=10.1175/JCLI-D-12-00228.1|osti=1172703 |url=http://www.escholarship.org/uc/item/9cv093s8|doi-access=free))</ref><ref>((Cite journal |last1=Armstrong McKay |first1=David I. |last2=Staal |first2=Arie |last3=Abrams |first3=Jesse F. |last4=Winkelmann |first4=Ricarda |last5=Sakschewski |first5=Boris |last6=Loriani |first6=Sina |last7=Fetzer |first7=Ingo |last8=Cornell |first8=Sarah E. |last9=Rockström |first9=Johan |last10=Lenton |first10=Timothy M. |date=2022-09-09 |title=Exceeding 1.5&nbsp;°C global warming could trigger multiple climate tipping points |journal=Science |volume=377 |issue=6611 |pages=eabn7950 |doi=10.1126/science.abn7950 |pmid=36074831 |hdl=10871/131584 |s2cid=252161375 |hdl-access=free ))</ref> Some scientists believe that [[Permafrost carbon cycle|carbon storage in permafrost]] globally is approximately 1600 gigatons. This is twice the atmospheric pool.<ref>((cite book |last1=Programme |first1=United Nations Environment |title=The Natural Fix? The Role of Ecosystems in Climate Mitigation: A UNEP Rapid Response Assessment |date=2009 |isbn=978-82-7701-057-1 |hdl=20.500.11822/7852 |pages=20, 55 |publisher=UNEP/Earthprint ))</ref>

== Wildlife and nature ==
((Further|Effects of climate change on biomes))

((See also|Extinction risk from climate change))[[File:Bleached coral (24577819729).jpg|thumb |upright=1.35|Part of the [[Great Barrier Reef]] in Australia in 2016 after a [[coral bleaching]] event (partly caused by rising ocean temperatures and [[marine heatwave]]s).]]Recent warming has had a big effect on natural biological systems.<ref name=":12">Rosenzweig, C., G. Casassa, D.J. Karoly, A. Imeson, C. Liu, A. Menzel, S. Rawlins, T.L. Root, B. Seguin, P. Tryjanowski, 2007: [https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg2-chapter1-1.pdf Chapter 1: Assessment of observed changes and responses in natural and managed systems]. [https://www.ipcc.ch/report/ar4/wg2/ Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change], M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 79-131.</ref>((rp|81)) [[Species]] worldwide are moving poleward to colder areas. On land, species may move to higher elevations. Marine species find colder water at greater depths.<ref name=":8">((cite journal |last1=Pecl |first1=Gretta T. |last2=Araújo |first2=Miguel B. |last3=Bell |first3=Johann D. |last4=Blanchard |first4=Julia |last5=Bonebrake |first5=Timothy C. |last6=Chen |first6=I-Ching |last7=Clark |first7=Timothy D. |last8=Colwell |first8=Robert K. |last9=Danielsen |first9=Finn |last10=Evengård |first10=Birgitta |last11=Falconi |first11=Lorena |last12=Ferrier |first12=Simon |last13=Frusher |first13=Stewart |last14=Garcia |first14=Raquel A. |last15=Griffis |first15=Roger B. |last16=Hobday |first16=Alistair J. |last17=Janion-Scheepers |first17=Charlene |last18=Jarzyna |first18=Marta A. |last19=Jennings |first19=Sarah |last20=Lenoir |first20=Jonathan |last21=Linnetved |first21=Hlif I. |last22=Martin |first22=Victoria Y. |last23=McCormack |first23=Phillipa C. |last24=McDonald |first24=Jan |last25=Mitchell |first25=Nicola J. |last26=Mustonen |first26=Tero |last27=Pandolfi |first27=John M. |last28=Pettorelli |first28=Nathalie |last29=Popova |first29=Ekaterina |last30=Robinson |first30=Sharon A. |last31=Scheffers |first31=Brett R. |last32=Shaw |first32=Justine D. |last33=Sorte |first33=Cascade J. B. |last34=Strugnell |first34=Jan M. |last35=Sunday |first35=Jennifer M. |last36=Tuanmu |first36=Mao-Ning |last37=Vergés |first37=Adriana |last38=Villanueva |first38=Cecilia |last39=Wernberg |first39=Thomas |last40=Wapstra |first40=Erik |last41=Williams |first41=Stephen E. |title=Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being |journal=Science |date=31 March 2017 |volume=355 |issue=6332 |pages=eaai9214 |doi=10.1126/science.aai9214 |pmid=28360268 |s2cid=206653576 |hdl=10019.1/120851 |url=http://ecite.utas.edu.au/115569 |hdl-access=free ))</ref> Climate change had the third biggest impact on nature out of various factors in the five decades up to 2020. Only change in land use and sea use and direct exploitation of organisms had a bigger impact.<ref>((Cite book|last=Díaz|first=S.|url=https://ipbes.net/system/tdf/inline/files/ipbes_global_assessment_report_summary_for_policymakers.pdf?file=1&type=node&id=36213|title=Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.|publisher=ISBES secretariat|year=2019|location=Bonn, Germany|page=12|display-authors=etal.|access-date=28 December 2019|archive-date=23 July 2021|archive-url=https://web.archive.org/web/20210723103208/https://ipbes.net/sites/default/files/inline/files/ipbes_global_assessment_report_summary_for_policymakers.pdf|url-status=live))</ref>

The impacts of climate change on nature are likely to become bigger in the next few decades.<ref>((Cite book|last=Díaz|first=S.|url=https://ipbes.net/system/tdf/inline/files/ipbes_global_assessment_report_summary_for_policymakers.pdf?file=1&type=node&id=36213|title=Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.|publisher=ISBES secretariat|year=2019|location=Bonn, Germany|page=16|display-authors=etal.|access-date=28 December 2019|archive-date=23 July 2021|archive-url=https://web.archive.org/web/20210723103208/https://ipbes.net/sites/default/files/inline/files/ipbes_global_assessment_report_summary_for_policymakers.pdf|url-status=live))</ref> The stresses caused by climate change, combine with other stresses on ecological systems such as land conversion, [[land degradation]], harvesting, and pollution. They threaten substantial damage to unique ecosystems. They can even result in their complete loss and the extinction of species.<ref>((cite journal |last1=McElwee |first1=Pamela |title=Climate Change and Biodiversity Loss |journal=Current History |date=1 November 2021 |volume=120 |issue=829 |pages=295–300 |doi=10.1525/curh.2021.120.829.295 |s2cid=240056779 |doi-access=free ))</ref><ref>((Cite journal |last1=Meyer |first1=Andreas L. S. |last2=Bentley |first2=Joanne |last3=Odoulami |first3=Romaric C. |last4=Pigot |first4=Alex L. |last5=Trisos |first5=Christopher H. |date=15 August 2022 |title=Risks to biodiversity from temperature overshoot pathways |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=377 |issue=1857 |pages=20210394 |doi=10.1098/rstb.2021.0394 |pmc=9234811 |pmid=35757884))</ref> This can disrupt key [[Species interaction|interactions between species]] within ecosystems. This is because species from one location do not leave the warming habitat at the same rate. The result is rapid changes in the way the ecosystem functions.<ref name=":8" /> Impacts include changes in regional rainfall patterns. Another is earlier leafing of trees and plants over many regions. Movements of species to higher latitudes and altitudes,<ref>((Cite web |last1=Wolfe |first1=Barrett |last2=Champion |first2=Curtis |last3=Pecl |first3=Gretta |last4=Strugnell |first4=Jan |last5=Watson |first5=Sue-Ann |title=Thousands of photos captured by everyday Australians reveal the secrets of our marine life as oceans warm |url=http://theconversation.com/thousands-of-photos-captured-by-everyday-australians-reveal-the-secrets-of-our-marine-life-as-oceans-warm-189231 |access-date=2023-05-09 |website=The Conversation |date=28 August 2022 |language=en))</ref> changes in bird migrations, and shifting of the oceans' plankton and fish from cold- to warm-adapted communities are other impacts.<ref name="NASA_2008">
((cite web
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 | title=Science Briefs: Warming Climate is Changing Life on Global Scale
 | author=Rosenzweig, C.
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))
</ref>

These changes of land and ocean ecosystems have direct effects on human well-being.<ref name=":5">((cite book |last1=Parmesan |first1=Camille |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Morecroft |first2=Mike |last3=Trisurat |first3=Yongyut |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |page=206 |chapter=Chapter 2: Terrestrial and Freshwater Ecosystems and their Services |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter02.pdf))</ref><ref name=":192">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: [https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter03.pdf Chapter 3: Oceans and Coastal Ecosystems and Their Services]. In: [https://www.ipcc.ch/report/ar6/wg2/ Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change] [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 379–550, doi:10.1017/9781009325844.005.</ref>((rp|385)) For instance, ocean ecosystems help with coastal protection and provide food.<ref name=":192" />((rp|385)) Freshwater and land ecosystems can provide water for human consumption. Furthermore, these ecosystems can store carbon. This helps to stabilize the climate system.<ref name=":5" />

=== Ecosystems on land ===
((Further|Effects of climate change on plant biodiversity))
Climate change is a major driver of [[biodiversity loss]] in different land types. These include cool [[conifer]] forests, [[savanna]]s, [[mediterranean climate|mediterranean-climate]] systems, [[tropical forest]]s, and the [[Arctic tundra]].<ref name=":14">Fischlin, A., G.F. Midgley, J.T. Price, R. Leemans, B. Gopal, C. Turley, M.D.A. Rounsevell, O.P. Dube, J. Tarazona, A.A. Velichko, 2007: [https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg2-chapter4-1.pdf Chapter 4: Ecosystems, their properties, goods, and services]. [https://www.ipcc.ch/report/ar4/wg2/ Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change], M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, 211-272.</ref>((rp|239)) In other ecosystems, [[land use|land-use]] change may be a stronger driver of biodiversity loss, at least in the near term.<ref name=":14" />((rp|239)) Beyond 2050, climate change may be the major cause of biodiversity loss globally.<ref name=":14" />((rp|239)) Climate change interacts with other pressures. These include habitat modification, pollution and [[invasive species]]. Through this interaction, climate change increases the risk of extinction for many terrestrial and freshwater species.<ref>((Cite book|last1=Settele|first1=J.|title=((Harvnb|IPCC AR5 WG2 A|2014))|last2=Scholes|first2=R.|last3=Betts|first3=R.|last4=Bunn|first4=S.|last5=Leadley|first5=P.|last6=Nepstad|first6=D.|last7=Overpeck|first7=J. T.|last8=Taboada|first8=M. A.|year=2014|page=275|chapter=Chapter 4: Terrestrial and Inland Water Systems|ref=((harvid|IPCC AR5 WG2 Ch4|2014))|display-authors=4|chapter-url=https://archive.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap4_FINAL.pdf|access-date=2 January 2020|archive-date=19 December 2019|archive-url=https://web.archive.org/web/20191219013722/https://archive.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap4_FINAL.pdf|url-status=live))</ref> At ((Convert|1.2|C-change)) of warming (around 2023<ref>((Cite web |last=Cuff |first=Madeleine |title=The first breach of 1.5&nbsp;°C will be a temporary but devastating failure |url=https://www.newscientist.com/article/2354824-the-first-breach-of-1-5c-will-be-a-temporary-but-devastating-failure/ |access-date=2023-05-09 |website=[[New Scientist]] |language=en-US))</ref>) some ecosystems are threatened by mass die-offs of trees and from heatwaves.<ref>((Cite web |title=Fact sheet - Biodiversity |url=https://www.ipcc.ch/report/ar6/wg2/downloads/outreach/IPCC_AR6_WGII_FactSheet_Biodiversity.pdf |website=[[IPCC Sixth Assessment Report]]))</ref> At ((Convert|2|C-change)) of warming, around 10% of species on land would become critically endangered. This differs by group. For instance [[insect]]s and [[salamander]]s are more vulnerable.<ref name=":1" />((rp|259))[[File:20210331 Global tree cover loss - World Resources Institute.svg|thumb| upright=1.35 |The rate of global tree cover loss has approximately doubled since 2001, to an annual loss approaching an area the size of Italy.<ref name="WorldResourcesInst_202103031">((cite news |ref=((harvid|World Resources Institute, 31 March|2021))
 |last1=Butler |first1=Rhett A.
 |title=Global forest loss increases in 2020
 |url=https://news.mongabay.com/2021/03/global-forest-loss-increases-in-2020-but-pandemics-impact-unclear/
 |work=Mongabay
 |date=31 March 2021
|archive-url=https://web.archive.org/web/20210401022404/https://news.mongabay.com/2021/03/global-forest-loss-increases-in-2020-but-pandemics-impact-unclear/
 |archive-date=1 April 2021
|url-status=live )) ● ''Mongabay'' graphing WRI data from ((cite web
 |title=Forest Loss / How much tree cover is lost globally each year?
 |url=https://research.wri.org/gfr/forest-extent-indicators/forest-loss
 |website=research.WRI.org
 |publisher=World Resources Institute — Global Forest Review
 |archive-url=https://archive.today/20230802052653/https://research.wri.org/gfr/forest-extent-indicators/forest-loss
 |archive-date=2 August 2023
|date=2023
 |url-status=live))</ref>]]
Rainfall on the [[Amazon rainforest]] is recycled when it [[evaporation|evaporates]] back into the atmosphere instead of [[surface runoff|running off]] away from the rainforest. This water is essential for sustaining the rainforest. [[Deforestation of the Amazon rainforest|Due to deforestation]] the rainforest is losing this ability. This effect is even worse because  climate change brings more frequent droughts to the area. The higher frequency of droughts in the first two decades of the 21st century and other data signal that a [[Tipping points in the climate system|tipping point]] from rainforest to savanna might be close. A 2019 study concluded that this ecosystem could begin a 50-year-long collapse to a savanna around 2021. After that it would become increasingly and disproportionally more difficult to prevent or reverse this shift.<ref>((cite journal |last1=Lovejoy |first1=Thomas E. |last2=Nobre |first2=Carlos |year=2019 |title=Amazon tipping point: Last chance for action |journal=Science Advances |volume=5 |issue=12 |page=eaba2949 |bibcode=2019SciA....5A2949L |doi=10.1126/sciadv.aba2949 |pmc=6989302 |pmid=32064324 |doi-access=free))</ref><ref>((cite web |date=10 March 2020 |title=Ecosystems the size of Amazon 'can collapse within decades' |url=https://www.theguardian.com/environment/2020/mar/10/ecosystems-size-of-amazon-rainforest-can-collapse-within-decades |url-status=live |archive-url=https://web.archive.org/web/20200412143545/https://www.theguardian.com/environment/2020/mar/10/ecosystems-size-of-amazon-rainforest-can-collapse-within-decades |archive-date=12 April 2020 |access-date=13 April 2020 |website=The Guardian ))</ref><ref name="10.1038/s41467-020-15029-x">((cite journal |last1=Cooper |first1=Gregory S. |last2=Willcock |first2=Simon |last3=Dearing |first3=John A. |date=10 March 2020 |title=Regime shifts occur disproportionately faster in larger ecosystems |journal=Nature Communications |volume=11 |issue=1 |pages=1175 |bibcode=2020NatCo..11.1175C |doi=10.1038/s41467-020-15029-x |pmc=7064493 |pmid=32157098 ))</ref>

=== Marine ecosystems ===
((Main|Effects of climate change on oceans#Impacts on marine life|Ocean acidification|Ocean deoxygenation))
[[File:Climate_change_threats_to_coral_reefs.png|thumb|upright=1.35|Climate change will affect [[coral reef]] ecosystems, through [[sea level rise]], changes to the frequency and intensity of tropical storms, and altered ocean circulation patterns. When combined, all of these impacts dramatically alter ecosystem function, as well as the goods and services coral reef ecosystems provide.<ref>((Cite web |last=US Department of Commerce |first=National Oceanic and Atmospheric Administration |title=How does climate change affect coral reefs? |url=https://oceanservice.noaa.gov/facts/coralreef-climate.html |access-date=2024-02-19 |website=oceanservice.noaa.gov |language=EN-US))</ref>]]
[[Marine heatwave]]s are happening more often. They have widespread impacts on life in the oceans. These include mass dying events and [[coral bleaching]].<ref>((cite journal |last1=Smale |first1=Dan A. |last2=Wernberg |first2=Thomas |last3=Oliver |first3=Eric C. J. |last4=Thomsen |first4=Mads |last5=Harvey |first5=Ben P. |last6=Straub |first6=Sandra C. |last7=Burrows |first7=Michael T. |last8=Alexander |first8=Lisa V. |last9=Benthuysen |first9=Jessica A. |last10=Donat |first10=Markus G. |last11=Feng |first11=Ming |last12=Hobday |first12=Alistair J. |last13=Holbrook |first13=Neil J. |last14=Perkins-Kirkpatrick |first14=Sarah E. |last15=Scannell |first15=Hillary A. |last16=Sen Gupta |first16=Alex |last17=Payne |first17=Ben L. |last18=Moore |first18=Pippa J. |title=Marine heatwaves threaten global biodiversity and the provision of ecosystem services |journal=Nature Climate Change |date=April 2019 |volume=9 |issue=4 |pages=306–312 |doi=10.1038/s41558-019-0412-1 |bibcode=2019NatCC...9..306S |s2cid=91471054 |url=https://api.research-repository.uwa.edu.au/ws/files/69272031/AAM_marine_heatwaves_threaten.pdf ))</ref> [[Harmful algal bloom|Harmful algae blooms]] have increased. This is in response to warming waters, loss of oxygen and [[eutrophication]].<ref>Bindoff, N.L., W.W.L. Cheung, J.G. Kairo, J. Arístegui, V.A. Guinder, R. Hallberg, N. Hilmi, N. Jiao, M.S. Karim, L. Levin, S. O'Donoghue, S.R. Purca Cuicapusa, B. Rinkevich, T. Suga, A. Tagliabue, and P. Williamson, 2019: [https://www.ipcc.ch/site/assets/uploads/sites/3/2022/03/07_SROCC_Ch05_FINAL.pdf Chapter 5: Changing Ocean, Marine Ecosystems, and Dependent Communities]. In: [https://www.ipcc.ch/srocc/ IPCC Special Report on the Ocean and Cryosphere in a Changing Climate] [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 447–587. ((doi|10.1017/9781009157964.007)).</ref>((rp|451)) Melting sea ice destroys habitat, including for [[algae]] that grows on its underside.<ref name="Riebesell">((Cite journal |last1=Riebesell |first1=Ulf |last2=Körtzinger |first2=Arne |last3=Oschlies |first3=Andreas |date=2009 |title=Sensitivities of marine carbon fluxes to ocean change |journal=PNAS |volume=106 |issue=49 |pages=20602–20609 |doi=10.1073/pnas.0813291106 |pmc=2791567 |pmid=19995981 |doi-access=free))</ref>

Ocean acidification can harm marine organisms in various ways. [[Marine biogenic calcification|Shell-forming organisms]] like [[oyster]]s are particularly vulnerable. Some [[phytoplankton]] and [[seagrass]] species may benefit. However, some of these are toxic to fish phytoplankton species. Their spread poses risks to fisheries and [[aquaculture]]. Fighting [[pollution]] can reduce the impact of acidification.<ref>((Cite journal |last1=Hall-Spencer |first1=Jason M. |last2=Harvey |first2=Ben P. |date=2019-05-10 |editor-last=Osborn |editor-first=Dan |title=Ocean acidification impacts on coastal ecosystem services due to habitat degradation |url=https://portlandpress.com/emergtoplifesci/article/3/2/197/219721/Ocean-acidification-impacts-on-coastal-ecosystem |journal=Emerging Topics in Life Sciences |language=en |volume=3 |issue=2 |pages=197–206 |doi=10.1042/ETLS20180117 |issn=2397-8554 |pmc=7289009 |pmid=33523154))</ref> 

[[Coral reef|Warm-water coral reefs]] are very sensitive to global warming and ocean acidification. Coral reefs provide a [[habitat]] for thousands of species. They provide [[ecosystem services]] such as [[coastal protection]] and food. But 70–90% of today's warm-water coral reefs will disappear even if warming is kept to ((Convert|1.5|C-change)).<ref name=":2">Hoegh-Guldberg, O., D. Jacob, M. Taylor, M. Bindi, S. Brown, I. Camilloni, A. Diedhiou, R. Djalante, K.L. Ebi, F. Engelbrecht, J.Guiot, Y. Hijioka, S. Mehrotra, A. Payne, S.I. Seneviratne, A. Thomas, R. Warren, and G. Zhou, 2018: [https://www.ipcc.ch/site/assets/uploads/sites/2/2022/06/SR15_Chapter_3_LR.pdf Chapter 3: Impacts of 1.5&nbsp;°C Global Warming on Natural and Human Systems]. In: [https://www.ipcc.ch/sr15/ Global Warming of 1.5&nbsp;°C. An IPCC Special Report on the impacts of global warming of 1.5&nbsp;°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty] [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T.Maycock, M.Tignor, and T. Waterfield (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 175-312. ((doi|10.1017/9781009157940.005)).</ref>((rp|179)) Coral reefs are framework organisms. They build physical structures that form habitats for other sea creatures. Other framework organisms are also at risk from climate change. [[Mangroves]] and [[seagrass]] are considered to be at moderate risk from lower levels of global warming.<ref name=":2" />((rp|225))

==Tipping points and irreversible impacts==
((Main|Tipping points in the climate system|Abrupt climate change))
[[File:Tipping_points_2022_list.jpeg|thumb|upright=1.35|There is a number of places around the globe which can pass a tipping point around a certain level of warming and eventually transition to a different state.<ref>((Cite web |title=Tipping Elements – big risks in the Earth System |url=https://www.pik-potsdam.de/en/output/infodesk/tipping-elements |publisher=[[Potsdam Institute for Climate Impact Research]] |access-date=31 January 2024 ))</ref><ref>((Cite journal |last=Armstrong McKay |first=David I. |last2=Staal |first2=Arie |last3=Abrams |first3=Jesse F. |last4=Winkelmann |first4=Ricarda |last5=Sakschewski |first5=Boris |last6=Loriani |first6=Sina |last7=Fetzer |first7=Ingo |last8=Cornell |first8=Sarah E. |last9=Rockström |first9=Johan |last10=Lenton |first10=Timothy M. |date=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 |doi=10.1126/science.abn7950 |issn=0036-8075))</ref>]]
The climate system exhibits "threshold behavior" or [[Tipping points in the climate system|tipping points]] when parts of the natural environment enter into a new state. Examples are the runaway loss of ice sheets or the dieback of forests.<ref name=":3">((cite book|title=In ((harvnb|USGCRP|2017))|last1=Kopp|first1=R. E.|last2=Hayhoe|first2=K.|last3=Easterling|first3=D.R.|last4=Hall|first4=T.|last5=Horton|first5=R.|last6=Kunkel|first6=K.E.|last7=LeGrande|first7=A.N.|work=US National Climate Assessment|year=2017|page=417|chapter=Chapter 15: Potential Surprises: Compound Extremes and Tipping Elements|ref=((harvid|USGCRP Chapter 15|2017))|display-authors=4|chapter-url=https://science2017.globalchange.gov/chapter/15/|archive-url=https://web.archive.org/web/20180820172529/https://science2017.globalchange.gov/chapter/15/|archive-date=20 August 2018|url-status=live))</ref><ref>((cite news|title=Climate emergency: world 'may have crossed tipping points'|newspaper=The Guardian|url=https://www.theguardian.com/environment/2019/nov/27/climate-emergency-world-may-have-crossed-tipping-points|last=Carrington|first=Damian|date=27 November 2019|access-date=4 January 2020|archive-date=4 January 2020|archive-url=https://web.archive.org/web/20200104180138/https://www.theguardian.com/environment/2019/nov/27/climate-emergency-world-may-have-crossed-tipping-points|url-status=live))</ref> Tipping behavior is found in all parts of the climate system. These include ecosystems, ice sheets, and the circulation of the ocean and atmosphere.<ref>((Cite web |last=Leahy |first=Stephen |date=2019-11-27 |title=Climate change driving entire planet to dangerous 'global tipping point' |url=https://www.nationalgeographic.com/science/article/earth-tipping-point |archive-url=https://web.archive.org/web/20210219175124/https://www.nationalgeographic.com/science/article/earth-tipping-point |url-status=dead |archive-date=19 February 2021 |access-date=2023-05-06 |website=National Geographic |language=en))</ref> Tipping points are studied using data from [[Paleoclimatology|Earth's distant past]] and by physical modeling.<ref name=":3" /> There is already moderate risk of global tipping points at ((Convert|1|C-change)) above pre-industrial temperatures. That becomes a high risk  at ((Convert|2.5|C-change)).<ref name=":2" />((rp|254, 258)) It is possible that some tipping points are close or have already been crossed. Examples are the West Antarctic and Greenland ice sheets, the Amazon rainforest, and warm-water coral reefs.<ref>((Cite journal |last1=Ripple |first1=William J |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M. |last4=Gregg |first4=Jillian W. |last5=Lenton |first5=Tim |author5-link=Tim Lenton |last6=Palomo |first6=Ignacio |last7=Eikelboom |first7=Jasper A. J. |last8=Law |first8=Beverly E. |last9=Huq |first9=Saleemul |last10=Duffy |first10=Philip B. |last11=Rockström |first11=Johan |date=28 July 2021 |title=World Scientists' Warning of a Climate Emergency 2021 |url=https://doi.org/10.1093/biosci/biab079 |journal=BioScience |volume=71 |issue=biab079 |pages=894–898 |doi=10.1093/biosci/biab079 |issn=0006-3568 |hdl-access=free |hdl=1808/30278))</ref>

Tipping points are perhaps the most dangerous aspect of future climate change, potentially leading to irreversible impacts on society.<ref>((cite journal |last1=Lontzek |first1=Thomas S. |last2=Cai |first2=Yongyang |last3=Judd |first3=Kenneth L. |last4=Lenton |first4=Timothy M. |title=Stochastic integrated assessment of climate tipping points indicates the need for strict climate policy |journal=Nature Climate Change |date=May 2015 |volume=5 |issue=5 |pages=441–444 |doi=10.1038/nclimate2570 |bibcode=2015NatCC...5..441L |hdl=10871/35041 |s2cid=84760180 |hdl-access=free ))</ref> A [[Atlantic meridional overturning circulation#Slowdown or possible shutdown of the thermohaline circulation|collapse of the Atlantic meridional overturning circulation]] would likely halve rainfall in India and lead to severe drops in temperature in Northern Europe.<ref>((Cite book |url=https://www.oecd-ilibrary.org/docserver/abc5a69e-en.pdf?expires=1683357411&id=id&accname=guest&checksum=793F81B2D97F534B5300C730F4C6EF59 |title=Climate Tipping Points: Insights for Effective Policy Action |vauthors=OECD |publisher=OECD Publishing |year=2022 |isbn=978-92-64-35465-4 |location=Paris |pages=29))</ref> Many tipping points are interlinked such that triggering one may lead to a cascade of effects.<ref>((Cite journal|last1=Lenton|first1=Timothy M.|last2=Rockström|first2=Johan|last3=Gaffney|first3=Owen|last4=Rahmstorf|first4=Stefan|last5=Richardson|first5=Katherine|last6=Steffen|first6=Will|last7=Schellnhuber|first7=Hans Joachim|date=2019|title=Climate tipping points — too risky to bet against|journal=Nature|volume=575|issue=7784|pages=592–595|doi=10.1038/d41586-019-03595-0|doi-access=free|pmid=31776487|bibcode=2019Natur.575..592L|hdl=10871/40141|hdl-access=free))</ref> This remains a possibility even well below ((Convert|2|C-change)) of warming.<ref>((cite news |last1=Carrington |first1=Damian |title=Climate tipping points could topple like dominoes, warn scientists |url=https://www.theguardian.com/environment/2021/jun/03/climate-tipping-points-could-topple-like-dominoes-warn-scientists |access-date=8 June 2021 |work=The Guardian |date=3 June 2021 |archive-date=7 June 2021 |archive-url=https://web.archive.org/web/20210607185015/https://www.theguardian.com/environment/2021/jun/03/climate-tipping-points-could-topple-like-dominoes-warn-scientists |url-status=live ))</ref> A 2018 study states that 45% of environmental problems, including those caused by climate change, are interconnected. This increases the risk of a [[domino effect]].<ref>((cite journal |last1=C. Rocha |first1=Juan |last2=Peterson |first2=Garry |last3=Bodin |first3=Örjan |last4=Levin |first4=Simon |title=Cascading regime shifts within and across scales |journal=Science |date=21 December 2018 |volume=362 |issue=6421 |pages=1379–1383 |bibcode=2018Sci...362.1379R |doi=10.1126/science.aat7850 |pmid=30573623 |s2cid=56582186 |doi-access=free ))</ref><ref>((cite news |last1=Watts |first1=Jonathan |title=Risks of 'domino effect' of tipping points greater than thought, study says |url=https://www.theguardian.com/environment/2018/dec/20/risks-of-domino-effect-of-tipping-points-greater-than-thought-study-says?CMP=greenlight_email |access-date=24 December 2018 |work=The Guardian |date=20 December 2018 |archive-date=7 February 2019 |archive-url=https://web.archive.org/web/20190207141140/https://www.theguardian.com/environment/2018/dec/20/risks-of-domino-effect-of-tipping-points-greater-than-thought-study-says?CMP=greenlight_email |url-status=live ))</ref> 

Further impacts may be irreversible, at least over the timescale of many human generations.<ref name=":23">Schneider, S.H., S. Semenov, A. Patwardhan, I. Burton, C.H.D. Magadza, M. Oppenheimer, A.B. Pittock, A. Rahman, J.B. Smith, A. Suarez and F. Yamin, 2007: [https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg2-chapter19-1.pdf Chapter 19: Assessing key vulnerabilities and the risk from climate change]. [https://www.ipcc.ch/report/ar4/wg2/ Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change], M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 779-810</ref>((rp|785)) This includes warming of the deep ocean and acidification. These are set to continue even when global temperatures stop rising.<ref>((Cite book |last1=Arias |first1=Paola A. |title=Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |last2=Bellouin |first2=Nicolas |last3=Coppola |first3=Erika |last4=Jones |first4=Richard G. |year=2021 |pages=106 |chapter=Technical Summary |display-authors=etal |chapter-url=https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_TS.pdf))</ref> In biological systems, the extinction of species would be an irreversible impact.<ref name=":23" />((rp|785)) In social systems, unique [[culture]]s may be lost.<ref name=":23" />((rp|785)) Climate change could make it more likely that endangered languages disappear.<ref name="climate and language">((cite journal |last1=Sabūnas |first1=Audrius |last2=Miyashita |first2=Takuya |last3=Fukui |first3=Nobuki |last4=Shimura |first4=Tomoya |last5=Mori |first5=Nobuhito |title=Impact Assessment of Storm Surge and Climate Change-Enhanced Sea Level Rise on Atoll Nations: A Case Study of the Tarawa Atoll, Kiribati |journal=Frontiers in Built Environment |doi=10.3389/fbuil.2021.752599|date=10 November 2021|volume=7 |doi-access=free ))</ref>

== Health, food security and water security ==
Humans have a climate niche. This is a certain range of temperatures in which they flourish. Outside that niche, conditions are less favourable. This leads to negative effects on health, food security and more. This niche is a mean annual temperature below 29&nbsp;°C. As of May 2023, 60 million people lived outside this niche. With every additional 0.1 degree of warming, 140 million people will be pushed out of it.<ref>((cite news |last1=Carrington |first1=Damian |title=Global heating will push billions outside 'human climate niche' |url=https://www.theguardian.com/environment/2023/may/22/global-heating-human-climate-niche |access-date=1 June 2023 |agency=The Guardian |date=22 May 2023))</ref>

=== Health ===
((excerpt|Effects of climate change on human health|paragraphs=1–3|file=no))
((excerpt|Effects of climate change on mental health|paragraphs=1–2|file=no))

=== Food security ===
((Main|Effects of climate change on agriculture#Global food security and undernutrition|Climate change and fisheries|Effects of climate change on livestock))
[[File:Hasegawa_2016_hunger_DALYs.png|thumb|upright=1.35|Projected changes in average food availability (represented as calorie consumption [[per capita]]), population at risk of hunger and [[disability-adjusted life years]] under two [[Shared Socioeconomic Pathways]]: the baseline, SSP2, and SSP3, scenario of high global rivalry and conflict. The red and the orange lines show projections for SSP3 assuming high and low intensity of future emissions and the associated climate change.<ref name="Hasegawa2016">((cite journal |last1=Hasegawa |first1=Tomoko |last2=Fujimori |first2=Shinichiro |last3=Takahashi |first3=Kiyoshi |last4=Yokohata |first4=Tokuta |last5=Masui |first5=Toshihiko |date=29 January 2016 |title=Economic implications of climate change impacts on human health through undernourishment |journal=Climatic Change |volume=136 |issue=2 |pages=189–202 |doi=10.1007/s10584-016-1606-4|doi-access=free |bibcode=2016ClCh..136..189H ))</ref>]]
Climate change will affect agriculture and food production around the world. The reasons include the effects of elevated CO<sub>2</sub> in the atmosphere. Higher temperatures and altered precipitation and [[transpiration]] regimes are also factors. Increased frequency of extreme events and modified weed, pest, and [[pathogen]] pressure are other factors.<ref>Easterling, W.E., P.K. Aggarwal, P. Batima, K.M. Brander, L. Erda, S.M. Howden, A. Kirilenko, J. Morton, J.-F. Soussana, J. Schmidhuber and F.N. Tubiello, 2007: [https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg2-chapter5-1.pdf Chapter 5: Food, fibre and forest products]. [https://www.ipcc.ch/report/ar4/wg2/ Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change], M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 273-313.</ref>((rp|282)) Droughts result in crop failures and the loss of pasture for livestock.<ref>((cite journal |last1=Ding |first1=Ya |last2=Hayes |first2=Michael J. |last3=Widhalm |first3=Melissa |title=Measuring economic impacts of drought: a review and discussion |journal=Disaster Prevention and Management |date=30 August 2011 |volume=20 |issue=4 |pages=434–446 |doi=10.1108/09653561111161752 |bibcode=2011DisPM..20..434D |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1198&context=natrespapers ))</ref> Loss and poor growth of livestock cause milk yield and meat production to decrease.<ref>((cite journal |last1=Ndiritu |first1=S. Wagura |last2=Muricho |first2=Geoffrey |date=2021 |title=Impact of climate change adaptation on food security: evidence from semi-arid lands, Kenya |url=https://www.researchsquare.com/article/rs-174615/v1.pdf?c=1631867581000 |journal=Climatic Change |volume=167 |issue=1–2 |pages=24 |bibcode=2021ClCh..167...24N |doi=10.1007/s10584-021-03180-3 |s2cid=233890082))</ref> The rate of soil erosion is 10–20 times higher than the rate of soil accumulation in agricultural areas that use [[no-till farming]]. In areas with [[Tilling (agriculture)|tilling]] it is 100 times higher. Climate change worsens this type of land degradation and [[desertification]].<ref name=":11" />((rp|5))

Climate change is projected to negatively affect all four pillars of food security. It will affect how much food is available. It will also affect how easy food is to access through prices, food quality, and how stable the food system is.<ref>((Cite book |last1=Mbow |first1=C. |url=https://www.ipcc.ch/srccl/ |title=IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems |last2=Rosenzweig |first2=C. |last3=Barioni |first3=L. G. |last4=Benton |first4=T. |last5=Herrero |first5=M. |last6=Krishnapillai |first6=M. V. |last7=Liwenga |first7=E. |last8=Pradhan |first8=P. |last9=Rivera-Ferre |first9=M. G. |year=2019 |page=442 |chapter=Chapter 5: Food Security |display-authors=4 |access-date=24 December 2019 |chapter-url=https://www.ipcc.ch/site/assets/uploads/2019/08/2f.-Chapter-5_FINAL.pdf |archive-url=https://web.archive.org/web/20191127221442/https://www.ipcc.ch/site/assets/uploads/2019/08/2f.-Chapter-5_FINAL.pdf |archive-date=27 November 2019 |url-status=live |first12=Y. |last15=Challinor |first10=T. |last16=Porter |first15=A. J. |last11=Tubiello |first16=J. R. |last12=Xu |first13=A. |first14=N. |last14=Benkeblia |first11=F. N. |last10=Sapkota |last13=Amanullah))</ref> Climate change is already affecting the productivity of wheat and other staples.<ref name="Vermeulen">((cite journal |last1=Vermeulen |first1=Sonja J. |last2=Campbell |first2=Bruce M. |last3=Ingram |first3=John S.I. |title=Climate Change and Food Systems |journal=Annual Review of Environment and Resources |date=21 November 2012 |volume=37 |issue=1 |pages=195–222 |doi=10.1146/annurev-environ-020411-130608 |s2cid=28974132 |doi-access=free ))</ref><ref name="Carter">((cite journal |last1=Carter |first1=Colin |last2=Cui |first2=Xiaomeng |last3=Ghanem |first3=Dalia |last4=Mérel |first4=Pierre |title=Identifying the Economic Impacts of Climate Change on Agriculture |journal=Annual Review of Resource Economics |date=5 October 2018 |volume=10 |issue=1 |pages=361–380 |doi=10.1146/annurev-resource-100517-022938 |s2cid=158817046 |url=https://escholarship.org/uc/item/50t4t5j9 ))</ref> 

In many areas, [[fishery]] catches are already decreasing because of global warming and changes in [[Biogeochemical cycle|biochemical cycles]]. In combination with [[overfishing]], warming waters decrease the amount of fish in the ocean.<ref name=":26" />((rp|12)) Per degree of warming, [[ocean biomass]] is expected to decrease by about 5%. Tropical and subtropical oceans are most affected, while there may be more fish in polar waters.<ref>((cite book |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter05.pdf |chapter=Chapter 5: Food, Fibre, and other Ecosystem Products |last1= Bezner Kerr |first1=Rachel |last2=Hasegawa |first2=Toshihiro  |last3=Lasco |first3=Rodel |last4=Bhatt  |first4=Indra | publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |display-authors=etal| title=Climate Change 2022: Impacts, Adaptation and Vulnerability| page=766))</ref>

=== Water security ===
((Further|Water security#Climate change))
Water resources can be affected by climate change in various ways. The total amount of freshwater available can change, for instance due to dry spells or droughts. Heavy rainfall and flooding can have an impact on water quality. They can transport pollutants into water bodies through increased [[surface runoff]]. In coastal regions, more salt may find its way into water resources due to higher sea levels and more intense storms. Higher temperatures also directly degrade water quality. This is because warm water contains less oxygen.<ref name="IPCC2022_FAQ4.1" /> Changes in the [[water cycle]] threaten existing and future water infrastructure. It will be harder to plan investments for water infrastructure. This is because there are significant uncertainties about future variability of the water cycle.<ref name="Sadoff-2020">((cite book |last1=Sadoff |first1=Claudia |title=Oxford Research Encyclopedia of Environmental Science |last2=Grey |first2=David |last3=Borgomeo |first3=Edoardo |year=2020 |isbn=978-0-19-938941-4 |chapter=Water Security |doi=10.1093/acrefore/9780199389414.013.609))</ref>

Between 1.5 and 2.5 billion people live in areas with regular [[water security]] issues. If global warming reaches ((Convert|4|C-change)), water insecurity would affect about twice as many people.<ref name="IPCC2022_FAQ4.1">((cite book |last1=Caretta |first1=Martina Angela |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Mukherji |first2=Aditi |publisher=[[Intergovernmental Panel on Climate Change]] |series=Contribution of Working Group II to the [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |at=FAQ4.1 |chapter=Chapter 4: Water |display-authors=etal |chapter-url=https://report.ipcc.ch/ar6wg2/pdf/IPCC_AR6_WGII_FinalDraft_Chapter04.pdf |access-date=12 March 2022 |archive-date=25 June 2022 |archive-url=https://web.archive.org/web/20220625205812/https://report.ipcc.ch/ar6wg2/pdf/IPCC_AR6_WGII_FinalDraft_Chapter04.pdf |url-status=dead ))</ref> Water resources are likely to decrease in most dry [[Subtropics|subtropical]] regions and [[mid-latitudes]]. But they will increase in high latitudes. However, variable streamflow means even regions with increased water resources can experience additional short-term [[Water scarcity|shortages]].<ref>Jiménez Cisneros, B.E., T. Oki, N.W. Arnell, G. Benito, J.G. Cogley, P. Döll, T. Jiang, and S.S. Mwakalila, 2014: [https://archive.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap3_FINAL.pdf Chapter 3: Freshwater resources]. In: [https://www.ipcc.ch/report/ar5/wg2/ Climate Change 2014: Impacts,Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change] [Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L.White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 229-269.</ref>((rp|251)) In the arid regions of India, China, the US and Africa dry spells and drought are already affecting  water availability.<ref name="IPCC2022_FAQ4.1" />

== Human settlement ==
Climate change is particularly likely to affect the Arctic, Africa, small islands, Asian megadeltas and [[Climate change in the Middle East and North Africa|the Middle East]] regions.<ref name="ar4 especially affected regions">((citation |title=Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change |access-date=28 December 2018 |archive-url=https://web.archive.org/web/20181223030123/https://archive.ipcc.ch/publications_and_data/ar4/syr/en/main.html |url-status=live |at=[http://archive.ipcc.ch/publications_and_data/ar4/syr/en/mains3-3-3.html Sec. 3.3.3 Especially affected systems, sectors and regions] |chapter=Synthesis report |chapter-url=http://archive.ipcc.ch/publications_and_data/ar4/syr/en/main.html |archive-date=23 December 2018)), in ((harvnb|IPCC AR4 SYR|2007)).</ref><ref>((cite journal |last1=Waha |first1=Katharina |date=April 2017 |title=Climate change impacts in the Middle East and Northern Africa (MENA) region and their implications for vulnerable population groups |url=https://www.researchgate.net/publication/316057764 |url-status=live |journal=Regional Environmental Change |volume=17 |issue=6 |pages=1623–1638 |doi=10.1007/s10113-017-1144-2 |bibcode=2017REnvC..17.1623W |hdl=1871.1/15a62c49-fde8-4a54-95ea-dc32eb176cf4 |s2cid=134523218 |archive-url=https://web.archive.org/web/20210723103211/https://www.researchgate.net/publication/316057764_Climate_change_impacts_in_the_Middle_East_and_Northern_Africa_MENA_region_and_their_implications_for_vulnerable_population_groups |archive-date=23 July 2021 |access-date=25 May 2020|hdl-access=free ))</ref> Low-latitude, less-developed regions are most at risk of experiencing negative climate change impacts.<ref name=":23" />((rp|795–796)) The ten countries of the [[ASEAN|Association of Southeast Asian Nations]] (ASEAN) are among the most vulnerable in the world to the negative effects of climate change. ASEAN's climate mitigation efforts are not in proportion to the climate change threats the region faces.<ref>((cite journal |last1=Overland |first1=Indra |last2=Sagbakken |first2=Haakon Fossum |last3=Chan |first3=Hoy-Yen |last4=Merdekawati |first4=Monika |last5=Suryadi |first5=Beni |last6=Utama |first6=Nuki Agya |last7=Vakulchuk |first7=Roman |date=December 2021 |title=The ASEAN climate and energy paradox |journal=Energy and Climate Change |volume=2 |page=100019 |doi=10.1016/j.egycc.2020.100019 |hdl-access=free |hdl=11250/2734506))</ref>

=== Impacts from heat ===
((Further|Climate change and cities|))[[File:Overlap between future population distribution and extreme heat.jpg|thumb|upright=1.35|Overlap between future population distribution and extreme heat in a high emission scenario<ref name="10.1073/pnas.2108146119">((cite journal |last1=Kemp |first1=Luke |last2=Xu |first2=Chi |last3=Depledge |first3=Joanna |last4=Ebi |first4=Kristie L. |authorlink4=Kristie Ebi |last5=Gibbins |first5=Goodwin |last6=Kohler |first6=Timothy A. |last7=Rockström |first7=Johan |authorlink7=Johan Rockström |last8=Scheffer |first8=Marten |authorlink8=Marten Scheffer |last9=Schellnhuber |first9=Hans Joachim |authorlink9=Hans Joachim Schellnhuber |last10=Steffen |first10=Will |last11=Lenton |first11=Timothy M. |title=Climate Endgame: Exploring catastrophic climate change scenarios |journal=Proceedings of the National Academy of Sciences |date=23 August 2022 |volume=119 |issue=34 |pages=e2108146119 |doi=10.1073/pnas.2108146119 |pmid=35914185 |pmc=9407216 |bibcode=2022PNAS..11908146K |doi-access=free ))</ref>]]Regions inhabited by a third of the human population could become as hot as the hottest parts of the Sahara within 50 years. This would happen if greenhouse gas emissions continue to grow rapdily without a change in patterns of population growth and without migration. The projected average temperature of above ((Convert|29|C)) for these regions would be outside the "human temperature niche". This is a range for climate that is biologically suitable for humans. It is  based on historical data of mean annual temperatures. The most affected regions have little [[Adaptation to climate change|adaptive capacity]].<ref>((cite news |date=5 May 2020 |title=Climate change: More than 3bn could live in extreme heat by 2070 |work=BBC News |url=https://www.bbc.co.uk/news/science-environment-52543589 |url-status=live |access-date=6 May 2020 |archive-url=https://web.archive.org/web/20200505153614/https://www.bbc.co.uk/news/science-environment-52543589 |archive-date=5 May 2020))</ref><ref>((cite journal |last1=Xu |first1=Chi |last2=Kohler |first2=Timothy A. |last3=Lenton |first3=Timothy M. |last4=Svenning |first4=Jens-Christian |last5=Scheffer |first5=Marten |date=26 May 2020 |title=Future of the human climate niche|journal=Proceedings of the National Academy of Sciences |volume=117 |issue=21 |pages=11350–11355 |bibcode=2020PNAS..11711350X |doi=10.1073/pnas.1910114117 |pmc=7260949 |pmid=32366654 |doi-access=free))</ref>

Increased extreme heat exposure from climate change and the [[Urban heat island|urban heat island effect]] threatens urban settlements.<ref>((Cite journal |last1=Tuholske |first1=Cascade |last2=Caylor |first2=Kelly |last3=Funk |first3=Chris |last4=Verdin |first4=Andrew |last5=Sweeney |first5=Stuart |last6=Grace |first6=Kathryn |last7=Peterson |first7=Pete |last8=Evans |first8=Tom |date=12 October 2021 |title=Global urban population exposure to extreme heat |journal=Proceedings of the National Academy of Sciences |volume=118 |issue=41 |pages=e2024792118 |bibcode=2021PNAS..11824792T |doi=10.1073/pnas.2024792118 |pmc=8521713 |pmid=34607944 |doi-access=free))</ref> This is made worse by the loss of shade from [[Urban forest|urban trees]] that cannot withstand the heat stress.<ref>((Cite journal |last1=Esperon-Rodriguez |first1=Manuel |last2=Tjoelker |first2=Mark G. |last3=Lenoir |first3=Jonathan |last4=Baumgartner |first4=John B. |last5=Beaumont |first5=Linda J. |last6=Nipperess |first6=David A. |last7=Power |first7=Sally A. |last8=Richard |first8=Benoît |last9=Rymer |first9=Paul D. |last10=Gallagher |first10=Rachael V. |date=October 2022 |title=Climate change increases global risk to urban forests |url=https://www.nature.com/articles/s41558-022-01465-8 |journal=Nature Climate Change |language=en |volume=12 |issue=10 |pages=950–955 |bibcode=2022NatCC..12..950E |doi=10.1038/s41558-022-01465-8 |issn=1758-6798 |s2cid=252401296))</ref>

In 2019, the [[Thomas Crowther (ecologist)|Crowther Lab]] from [[ETH Zurich]] paired the climatic conditions of 520 major cities worldwide with the predicted climatic conditions of cities in 2050. It found that 22% of the major cities would have climatic conditions that do not exist in any city today. For instance, 2050 London would have a climate similar to 2019 Melbourne in Australia. Athens and Madrid would be like Fez in Morocco.  Nairobi in Kenya would be like Maputo in Mozambique. The Indian city Pune would be like Bamako in Mali and Bamako would be like Niamey in Niger. Brasilia would be like Goiania, both in Brazil.<ref>[https://crowtherlab.pageflow.io/cities-of-the-future-visualizing-climate-change-to-inspire-action#213121 Cities of the future: visualizing climate change to inspire action, current vs future cities], Crowther Lab, Department für Umweltsystemwissenschaften, Institut für integrative Biologie, ETH Zürich, zugegriffen: 11 July 2019.</ref><ref>[https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0217592&type=printable Understanding climate change from a global analysis of city analogues], Bastin J-F, Clark E, Elliott T, Hart S, van den Hoogen J, Hordijk I, et al. (2019), PLOS ONE 14(7): e0217592, Crowther Lab, Department for Environmental Systems Science, Institut for Integrative Biology, ETH Zürich, 10 July 2019.</ref>

=== Low-lying coastal regions ===
((Further|Effects of climate change on small island countries))Low-lying cities and other settlements near the sea face multiple simultaneous risks from climate change. They face flooding risks from sea level rise. In addition they may face impacts from more severe storms, ocean acidification, and [[Saltwater intrusion|salt intrusion]] into the groundwater.  Changes like continued development in exposed areas increase the risks that these regions face.<ref>Glavovic, B.C., R. Dawson, W. Chow, M. Garschagen, M. Haasnoot, C. Singh, and A. Thomas, 2022: [https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_CCP2.pdf Cross-Chapter Paper 2: Cities and Settlements by the Sea]. 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 [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, US, pp. 2163–2194, ((doi|10.1017/9781009325844.019))</ref> 
[[File:Cyclone Nargis flooding before-and-after.jpg|thumb|upright=1.35|Floodplains and low-lying coastal areas will flood more frequently due to climate change, like this area of [[Myanmar]] which was submerged by [[Cyclone Nargis]].]]
[[Population density]] on the coasts is high. Estimates of the number of people at risk of [[coastal flooding]] from climate-driven sea level rise vary. Estimates range from 190 million<ref>[https://www.bbc.com/news/science-environment-50236882 Climate change: Sea level rise to affect 'three times more people'] ((Webarchive|url=https://web.archive.org/web/20200106151232/https://www.bbc.com/news/science-environment-50236882|date=6 January 2020)), BBC News, 30 October 2019</ref> to 300 million. It could even be 640 million in a worst-case scenario related to the instability of the Antarctic ice sheet.<ref>[https://www.theguardian.com/environment/2019/oct/29/rising-sea-levels-pose-threat-to-homes-of-300m-people-study Rising sea levels pose threat to homes of 300m people – study] ((Webarchive|url=https://web.archive.org/web/20191230044325/https://www.theguardian.com/environment/2019/oct/29/rising-sea-levels-pose-threat-to-homes-of-300m-people-study|date=30 December 2019)), ''The Guardian'', 29 October 2019</ref><ref>((Cite journal |last1=Kulp |first1=Scott A. |last2=Strauss |first2=Benjamin H. |date=29 October 2019 |title=New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding |journal=Nature Communications |volume=10 |issue=1 |page=4844 |bibcode=2019NatCo..10.4844K |doi=10.1038/s41467-019-12808-z |pmc=6820795 |pmid=31664024 |s2cid=204962583))</ref> People are most affected in the densely-populated low-lying [[River delta|megadeltas]] of Asia and Africa.<ref name="IPCC_4th_assessment_f2">((cite web |author=IPCC |year=2007 |title=3.3.1 Impacts on systems and sectors. In (section): Synthesis Report. In: Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)) |url=http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains3-3-1.html |url-status=dead |archive-url=https://web.archive.org/web/20181103102842/http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains3-3-1.html |archive-date=3 November 2018 |access-date=10 April 2010 |publisher=Book version: IPCC, Geneva, Switzerland. This version: IPCC website))</ref>

[[Small Island Developing States|Small island developing states]] are especially vulnerable. They are likely to experience more intense storm surges, salt water intrusion and coastal destruction.<ref name="Rasheed_Hassan_2019">((cite web |last1=Rasheed Hassan |first1=Hussain |last2=Cliff |first2=Valerie |date=24 September 2019 |title=For small island nations, climate change is not a threat. It's already here |url=https://www.weforum.org/agenda/2019/09/island-nations-maldives-climate-change/ |access-date=28 January 2021 |website=World Economic Fourm))</ref> Low-lying small islands in the Pacific, Indian, and Caribbean regions even risk permanent inundation. This would displace their population.<ref name="Barnett_2003">((cite journal |last1=Barnett |first1=Jon |last2=Adger |first2=W. Neil |date=December 2003 |title=Climate Dangers and Atoll Countries |journal=Climatic Change |volume=61 |issue=3 |pages=321–337 |doi=10.1023/B:CLIM.0000004559.08755.88 |s2cid=55644531))</ref><ref name="Church_2006">((cite journal |last1=Church |first1=John A. |last2=White |first2=Neil J. |last3=Hunter |first3=John R. |date=2006 |title=Sea-level rise at tropical Pacific and Indian Ocean islands |journal=Global and Planetary Change |volume=53 |issue=3 |pages=155–168 |bibcode=2006GPC....53..155C |doi=10.1016/j.gloplacha.2006.04.001))
</ref><ref name="Mimura_1999">((cite journal |last=Mimura |first=N |date=1999 |title=Vulnerability of island countries in the South Pacific to sea level rise and climate change |journal=Climate Research |volume=12 |pages=137–143 |bibcode=1999ClRes..12..137M |doi=10.3354/cr012137 |doi-access=free))
</ref> On the islands of Fiji, Tonga and western Samoa, migrants from outer islands inhabit low and unsafe areas along the coasts.<ref name="Mimura_1999" /> The entire populations of small [[atoll]] nations such as Kiribati, Maldives, the Marshall Islands, and Tuvalu are at risk of being displaced.<ref name="Tsosie_2007">((cite journal |last=Tsosie |first=Rebecca |year=2007 |title=Indigenous People and Environmental Justice:The Impact of Climate Change |journal=University of Colorado Law Review |url=https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1399659|volume=78 |pages=1625|ssrn=1399659 ))
</ref><ref name="Barnett_2003" />  This could raise issues of [[statelessness]].<ref>
((cite report|date=May 2011 |last=Park|first=Susan|title=Climate change and the risk of statelessness |url=https://www.unhcr.org/media/30513 |access-date=29 April 2023))
</ref> Several factors increase their vulnerability. These are small size, isolation from other land, low financial resources, and lack of protective infrastructure.<ref name="Barnett_2003" />

((anchor|Climate doom loop))

== Impacts on societies ==
Climate change has many impacts on society.<ref>((cite journal |last1=Dietz |first1=Thomas |last2=Shwom |first2=Rachael L. |last3=Whitley |first3=Cameron T. |title=Climate Change and Society |journal=[[Annual Review of Sociology]] |date=2020 |volume=46 |issue=1 |pages=135–158 |doi=10.1146/annurev-soc-121919-054614 |doi-access=free))</ref> It affects [[Effects of climate change on human health|health]], the availability of drinking water and food, [[Economic inequality|inequality]] and economic growth. The effects of climate change are often interlinked. They can exacerbate each other as well as existing vulnerabilities.<ref>((cite journal |last1=O'Brien |first1=Karen L |last2=Leichenko |first2=Robin M |date=1 October 2000 |title=Double exposure: assessing the impacts of climate change within the context of economic globalization |journal=Global Environmental Change |volume=10 |issue=3 |pages=221–232 |doi=10.1016/S0959-3780(00)00021-2 ))</ref><ref>((cite journal |last1=Zhang |first1=Li |last2=Chen |first2=Fu |last3=Lei |first3=Yongdeng |year=2020 |title=Climate change and shifts in cropping systems together exacerbate China's water scarcity |journal=Environmental Research Letters |volume=15 |issue=10 |page=104060 |bibcode=2020ERL....15j4060Z |doi=10.1088/1748-9326/abb1f2 |s2cid=225127981|doi-access=free ))</ref><ref>((cite journal |last1=Cramer |first1=Wolfgang |last2=Guiot |first2=Joël |last3=Fader |first3=Marianela |last4=Garrabou |first4=Joaquim |last5=Gattuso |first5=Jean-Pierre |last6=Iglesias |first6=Ana |last7=Lange |first7=Manfred A. |last8=Lionello |first8=Piero |last9=Llasat |first9=Maria Carmen |last10=Paz |first10=Shlomit |last11=Peñuelas |first11=Josep |date=November 2018 |title=Climate change and interconnected risks to sustainable development in the Mediterranean |url=http://ddd.uab.cat/record/203562 |journal=Nature Climate Change |volume=8 |issue=11 |pages=972–980 |bibcode=2018NatCC...8..972C |doi=10.1038/s41558-018-0299-2 |s2cid=92556045 |first13=Andrea |last14=Tsimplis |first12=Maria |last13=Toreti |first15=Elena |last15=Xoplaki |first14=Michael N. |last12=Snoussi|hdl=10261/172731 |hdl-access=free ))</ref> Some areas may become too hot for humans to live in.<ref>((cite news |last1=Watts |first1=Jonathan |date=5 May 2020 |title=One billion people will live in insufferable heat within 50 years – study |work=The Guardian |url=https://www.theguardian.com/environment/2020/may/05/one-billion-people-will-live-in-insufferable-heat-within-50-years-study |url-status=live |access-date=7 May 2020 |archive-url=https://web.archive.org/web/20200507000700/https://www.theguardian.com/environment/2020/may/05/one-billion-people-will-live-in-insufferable-heat-within-50-years-study |archive-date=7 May 2020))</ref><ref>((cite journal |last1=Xu |first1=Chi |last2=M. Lenton |first2=Timothy |last3=Svenning |first3=Jens-Christian |last4=Scheffer |first4=Marten |date=26 May 2020 |title=Future of the human climate niche |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=117 |issue=21 |pages=11350–11355 |doi=10.1073/pnas.1910114117 |pmc=7260949 |pmid=32366654 |bibcode=2020PNAS..11711350X |doi-access=free))</ref> Climate-related changes or disasters may lead people in some areas to move to other parts of the country or to other countries.

Some scientists describe the effects of climate change, with continuing increases in greenhouse gas emissions, as a "climate emergency" or "[[climate crisis]]".<ref>((cite journal |last1=Ripple |first1=William J |last2=Wolf |first2=Christopher |last3=Newsome |first3=Thomas M |last4=Barnard |first4=Phoebe |last5=Moomaw |first5=William R |title=Corrigendum: World Scientists' Warning of a Climate Emergency |journal=BioScience |date=1 January 2020 |volume=70 |issue=1 |pages=100 |doi=10.1093/biosci/biz152 |doi-access=free ))</ref><ref>[https://www.smithsonianmag.com/science-nature/scientists-around-world-declare-climate-emergency-180973462/ Scientists Around the World Declare 'Climate Emergency'] ((Webarchive|url=https://web.archive.org/web/20191216235752/https://www.smithsonianmag.com/science-nature/scientists-around-world-declare-climate-emergency-180973462/|date=16 December 2019)), Smithsonian Magazine, 5 November 2019</ref> Some researchers<ref>[https://edition.cnn.com/2019/06/04/health/climate-change-existential-threat-report-intl/index.html Climate change could pose 'existential threat' by 2050: report] ((Webarchive|url=https://web.archive.org/web/20200127102054/https://edition.cnn.com/2019/06/04/health/climate-change-existential-threat-report-intl/index.html|date=27 January 2020)), CNN, 5 June 2019.</ref><ref>((cite journal |last1=Lenton |first1=Timothy M. |last2=Rockström |first2=Johan |last3=Gaffney |first3=Owen |last4=Rahmstorf |first4=Stefan |last5=Richardson |first5=Katherine |last6=Steffen |first6=Will |last7=Schellnhuber |first7=Hans Joachim |title=Climate tipping points — too risky to bet against |journal=Nature |date=November 2019 |volume=575 |issue=7784 |pages=592–595 |doi=10.1038/d41586-019-03595-0 |pmid=31776487 |bibcode=2019Natur.575..592L |hdl=10871/40141 |s2cid=208330359 |hdl-access=free ))</ref> and activists<ref>[https://www.theguardian.com/commentisfree/2019/sep/25/greta-thunberg-showed-the-world-what-it-means-to-lead Greta Thunberg showed the world what it means to lead] ((Webarchive|url=https://web.archive.org/web/20211029085350/https://www.theguardian.com/commentisfree/2019/sep/25/greta-thunberg-showed-the-world-what-it-means-to-lead|date=29 October 2021)), ''The Guardian,'' 25 September 2019</ref> describe them as an existential threat to civilization. Some define these threats under [[climate security]]. The consequences of climate change, and the failure to address it, can distract people from tackling its root causes. This leads to what some researchers have termed a "climate doom loop".<ref name="IPPR_20230200">((cite web |last1=Laybourn |first1=Laurie |last2=Throp |first2=Henry |last3=Sherman |first3=Suzannah |website=Institute for Public Policy Research (IPPR) |title=1.5&nbsp;°C – Dead or Alive? The Risks to Transformational Change Reaching and Breaching the Paris Agreement Goal |url=https://www.ippr.org/files/2023-02/1676546139_1.5c-dead-or-alive-feb23.pdf |publisher=Chatham House, the Royal Institute of International Affairs |archive-url=https://web.archive.org/web/20230309035603/https://www.ippr.org/files/2023-02/1676546139_1.5c-dead-or-alive-feb23.pdf |archive-date=9 March 2023 |date=February 2023 |url-status=live)) Explained by Tigue, Kristoffer, ((cite web |title=What's a Climate 'Doom Loop?' These Researchers Fear We're Heading Into One |url=https://insideclimatenews.org/todaysclimate/whats-a-climate-doom-loop-these-researchers-fear-were-heading-into-one/ |publisher=Inside Climate News |archive-url=https://web.archive.org/web/20230306041102/https://insideclimatenews.org/todaysclimate/whats-a-climate-doom-loop-these-researchers-fear-were-heading-into-one/ |archive-date=6 March 2023 |date=17 February 2023 |url-status=live))</ref>

=== Displacement and migration ===
((Further|Climate migration|Climate change adaptation#Migration and managed retreat))
Displacement is when people move within a country. Migration is when they move to another country. Some people use the terms interchangeably. Climate change affects displacement in several ways. More frequent and severe weather-related disasters may increase involuntary displacement. These destroy homes and habitats. Climate impacts such as [[desertification]] and rising sea levels gradually erode livelihoods. They force communities to abandon traditional homelands. Other forms of migration are adaptive and voluntary. They are based on individual or household decisions.<ref name=":142">Cissé, G., R. McLeman, H. Adams, P. Aldunce, K. Bowen, D. Campbell-Lendrum, S. Clayton, K.L. Ebi, J. Hess, C. Huang, Q. Liu, G. McGregor, J. Semenza, and M.C. Tirado, 2022: [https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter07.pdf Health, Wellbeing, and the Changing Structure of Communities.] In: [https://www.ipcc.ch/report/ar6/wg2/ Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change] [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, US, pp. 1041–1170, ((doi|10.1017/9781009325844.009))</ref>((rp|1079)) On the other hand, some households may fall into poverty or get poorer due to climate change. This limits their ability to move to less affected areas.<ref name=":25">((Cite journal |last1=Kaczan |first1=David J. |last2=Orgill-Meyer |first2=Jennifer |date=2020 |title=The impact of climate change on migration: a synthesis of recent empirical insights |journal=Climatic Change |volume=158 |issue=3 |pages=281–300 |bibcode=2020ClCh..158..281K |doi=10.1007/s10584-019-02560-0 |s2cid=207988694))</ref>

Migration due to climate and weather is usually within countries. But it is long-distance. Slow-onset disasters such as droughts and heat are more likely to cause long-term migration than weather disasters like floods.<ref name=":25" /> Migration due to desertification and reduced soil fertility is typically from rural areas in developing countries to towns and cities.<ref name="wdr migration">((citation |author=The World Bank |title=Managing social risks: Empower communities to protect themselves |access-date=29 August 2011 |archive-url=https://web.archive.org/web/20110507173000/http://siteresources.worldbank.org/INTWDR2010/Resources/5287678-1226014527953/Chapter-2.pdf |url-status=live |chapter=Part One: Chapter 2: Reducing Human Vulnerability: Helping People Help Themselves |date=6 November 2009 |publisher=World Bank Publications |isbn=9780821379882 |chapter-url=https://books.google.com/books?id=MGOJs900Q-MC |archive-date=7 May 2011))</ref>((rp|109))

According to the [[Internal Displacement Monitoring Centre]], extreme weather events displaced approximately 30 million people in 2020. Violence and wars displaced approximately 10 million in the same year. There may have been a contribution of climate change to these conflicts.<ref>((cite book |title=GRID Internal displacement in a changing climate |date=2021 |publisher=Internal Displacement Monitoring Center |pages=42–53 |url=https://www.internal-displacement.org/sites/default/files/publications/documents/grid2021_idmc.pdf#page=42 |access-date=24 May 2021))</ref><ref>((cite news |last1=Niranjan |first1=Ajit |title=Extreme Weather Displaces Record Numbers of People as Temperatures Rise |url=https://www.ecowatch.com/extreme-weather-climate-refugees-2653071338.html |access-date=24 May 2021 |agency=Ecowatch |date=21 May 2021))</ref> In 2018, the World Bank estimated that climate change will cause [[internal migration]] of between 31 and 143 million people by 2050. This would be as they escape crop failures, water scarcity, and sea level rise. The study covered only Sub-Saharan Africa, South Asia, and Latin America.<ref>[https://www.nationalgeographic.com/news/2018/03/climate-migrants-report-world-bank-spd/ 143 Million People May Soon Become Climate Migrants] ((Webarchive|url=https://web.archive.org/web/20191219010304/https://www.nationalgeographic.com/news/2018/03/climate-migrants-report-world-bank-spd/|date=19 December 2019)), National Geographic, 19 March 2018</ref><ref>((Cite book |last1=Kumari Rigaud |first1=Kanta |url=https://openknowledge.worldbank.org/bitstream/handle/10986/29461/WBG_ClimateChange_Final.pdf |title=Groundswell: preparing for internal climate migration |last2=de Sherbinin |first2=Alex |last3=Jones |first3=Bryan |publisher=The World Bank |year=2018 |location=Washington DC |page=xxi |display-authors=etal |access-date=29 December 2019 |archive-url=https://web.archive.org/web/20200102172649/https://openknowledge.worldbank.org/bitstream/handle/10986/29461/WBG_ClimateChange_Final.pdf |archive-date=2 January 2020 |url-status=live))</ref>
[[File:Majuro_-_Main_Atoll_of_the_RMI.jpg|thumb|upright=1.35|Sea level rise at the [[Marshall Islands]], reaching the edge of a village (from the documentary ''One Word'')]]

=== Conflict ===
((Main|Climate security))

[[File:Overlap between state fragility, extreme heat, and nuclear and biological catastrophic hazards.jpg|thumb|upright=1.35|Overlap between state fragility, extreme heat, and nuclear and biological catastrophic [[hazard]]s<ref name="10.1073/pnas.2108146119" />]]
Climate change is unlikely to cause international [[war]]s in the foreseeable future. There is increasing consensus among experts that climate change increases the risk for intrastate conflicts, such as [[civil war]]s, [[communal violence]], or [[protest]]s.<ref name=":15">((cite journal |last1=Mach |first1=Katharine J. |last2=Kraan |first2=Caroline M. |last3=Adger |first3=W. Neil |last4=Buhaug |first4=Halvard |last5=Burke |first5=Marshall |last6=Fearon |first6=James D. |last7=Field |first7=Christopher B. |last8=Hendrix |first8=Cullen S. |last9=Maystadt |first9=Jean-Francois |last10=O'Loughlin |first10=John |last11=Roessler |first11=Philip |last12=Scheffran |first12=Jürgen |last13=Schultz |first13=Kenneth A. |last14=von Uexkull |first14=Nina |date=July 2019 |title=Climate as a risk factor for armed conflict |url=https://eprints.lancs.ac.uk/id/eprint/134710/1/Mach_2019_accepted_manuscript.pdf |url-status=dead |journal=Nature |volume=571 |issue=7764 |pages=193–197 |bibcode=2019Natur.571..193M |doi=10.1038/s41586-019-1300-6 |pmid=31189956 |s2cid=186207310 |archive-url=https://web.archive.org/web/20220412022049/https://eprints.lancs.ac.uk/id/eprint/134710/1/Mach_2019_accepted_manuscript.pdf |archive-date=12 April 2022 |access-date=21 November 2022 |hdl=10871/37969))</ref> The most recent [[Intergovernmental Panel on Climate Change|IPCC]] report concludes: "[[Climate hazard]]s have affected armed conflict within countries (medium confidence), but the influence of climate is small compared to socio-economic, political, and cultural factors (high confidence)."<ref name=":28">((Cite book |last=Intergovernmental Panel on Climate Change (IPCC) |url=https://www.cambridge.org/core/books/climate-change-2022-impacts-adaptation-and-vulnerability/161F238F406D530891AAAE1FC76651BD |title=Climate Change 2022 – Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change |date=2023 |publisher=Cambridge University Press |location=Cambridge |page=1045 |doi=10.1017/9781009325844|isbn=978-1-009-32584-4 ))</ref>

Climate change can increase conflict risks by causing tensions about scarce resources like food, water and land, by weakening state institutions, by reducing the [[opportunity cost]]s for impoverished individuals to join armed groups, and by causing tensions related to (climate-induced) migration.<ref>((cite journal |last1=Koubi |first1=Vally |year=2019 |title=Climate Change and Conflict |journal=Annual Review of Political Science |volume=22 |pages=343–360 |doi=10.1146/annurev-polisci-050317-070830 |doi-access=free))</ref><ref name=":28" /> Recently, experts have expressed concerns that efforts to [[Climate change mitigation|mitigate]] or [[Climate change adaptation|adapt]] to climate change can also cause conflicts, for instance due to higher food and energy prices or when people are forcibly re-located from vulnerable areas.<ref>((Cite journal |last1=Gilmore |first1=Elisabeth A. |last2=Buhaug |first2=Halvard |date=17 June 2021 |title=Climate mitigation policies and the potential pathways to conflict: Outlining a research agenda |journal=WIREs Climate Change |language=en |volume=12 |issue=5 |pages=e722 |doi=10.1002/wcc.722 |issn=1757-7780 |pmc=8459245 |pmid=34594401|bibcode=2021WIRCC..12E.722G ))</ref><ref>((Cite journal |last=Siddiqi |first=Ayesha |date=20 April 2022 |title=The missing subject: Enabling a postcolonial future for climate conflict research |url=https://compass.onlinelibrary.wiley.com/doi/10.1111/gec3.12622 |journal=Geography Compass |language=en |volume=16 |issue=5 |doi=10.1111/gec3.12622 |bibcode=2022GComp..16E2622S |issn=1749-8198))</ref>

Research has shown that climate change is not the most important conflict driver, and that it can only affect conflict risks under certain circumstances.<ref name=":15" /> Relevant context factors include agricultural dependence, a history of political instability, poverty, and the political exclusion of ethnic groups.<ref>((Cite journal |last1=Ide |first1=Tobias |last2=Brzoska |first2=Michael |last3=Donges |first3=Jonathan F. |last4=Schleussner |first4=Carl-Friedrich |date=2020-05-01 |title=Multi-method evidence for when and how climate-related disasters contribute to armed conflict risk |url=https://www.sciencedirect.com/science/article/pii/S0959378019307307 |journal=Global Environmental Change |volume=62 |pages=102063 |doi=10.1016/j.gloenvcha.2020.102063 |issn=0959-3780))</ref><ref>((Cite journal |last1=von Uexkull |first1=Nina |last2=Croicu |first2=Mihai |last3=Fjelde |first3=Hanne |last4=Buhaug |first4=Halvard |date=17 October 2016 |title=Civil conflict sensitivity to growing-season drought |journal=Proceedings of the National Academy of Sciences |language=en |volume=113 |issue=44 |pages=12391–12396 |doi=10.1073/pnas.1607542113 |doi-access=free |issn=0027-8424 |pmc=5098672 |pmid=27791091|bibcode=2016PNAS..11312391V ))</ref><ref name=":29">((Cite journal |last=Ide |first=Tobias |date=2023 |title=Rise or Recede? How Climate Disasters Affect Armed Conflict Intensity |url=https://doi.org/10.1162/isec_a_00459 |journal=International Security |volume=47 |issue=4 |pages=50–78 |doi=10.1162/isec_a_00459 |issn=0162-2889|doi-access=free ))</ref> Climate change has thus been described as a "threat multiplier".<ref>((cite journal |last=Spaner |first=J S |author2=LeBali, H |date=October 2013 |title=The Next Security Frontier |url=http://www.usni.org/magazines/proceedings/2013-10/next-security-frontier |url-status=live |journal=Proceedings of the United States Naval Institute |volume=139 |issue=10 |pages=30–35 |archive-url=https://web.archive.org/web/20181107014339/https://www.usni.org/magazines/proceedings/2013-10/next-security-frontier |archive-date=7 November 2018 |access-date=23 November 2015))</ref> Yet, an impact of climate change on specific conflicts like the [[Syrian civil war]]<ref>((Cite journal |last1=Dinc |first1=Pinar |last2=Eklund |first2=Lina |date=2023-07-01 |title=Syrian farmers in the midst of drought and conflict: the causes, patterns, and aftermath of land abandonment and migration |url=https://www.tandfonline.com/doi/full/10.1080/17565529.2023.2223600 |journal=Climate and Development |language=en |pages=1–14 |doi=10.1080/17565529.2023.2223600 |issn=1756-5529|doi-access=free ))</ref><ref>((Cite journal |last1=Ash |first1=Konstantin |last2=Obradovich |first2=Nick |date=2020 |title=Climatic Stress, Internal Migration, and Syrian Civil War Onset |url=http://journals.sagepub.com/doi/10.1177/0022002719864140 |journal=Journal of Conflict Resolution |language=en |volume=64 |issue=1 |pages=3–31 |doi=10.1177/0022002719864140 |issn=0022-0027))</ref> or the [[Darfur genocide|armed conflict in Darfur]]<ref>((Cite journal |last=De Juan |first=Alexander |date=2015-03-01 |title=Long-term environmental change and geographical patterns of violence in Darfur, 2003–2005 |url=https://www.sciencedirect.com/science/article/pii/S0962629814000821 |journal=Political Geography |volume=45 |pages=22–33 |doi=10.1016/j.polgeo.2014.09.001 |issn=0962-6298))</ref><ref>((cite news |last1=Perez |first1=Ines |date=4 March 2013 |title=Climate Change and Rising Food Prices Heightened Arab Spring |url=https://www.scientificamerican.com/article/climate-change-and-rising-food-prices-heightened-arab-spring/ |url-status=live |archive-url=https://web.archive.org/web/20180820074131/https://www.scientificamerican.com/article/climate-change-and-rising-food-prices-heightened-arab-spring/ |archive-date=20 August 2018 |access-date=21 August 2018 |work=Republished with permission by Scientific American |publisher=Environment & Energy Publishing, LLC))</ref> remains hard to proof.

In some cases, climate change could also decrease conflict risks. This happens either if climate-related disasters impose financial and logistical constraints on conflict parties<ref name=":29" /><ref>((Cite journal |last=Walch |first=Colin |date=5 February 2018 |title=Weakened by the storm: Rebel group recruitment in the wake of natural disasters in the Philippines |url=http://journals.sagepub.com/doi/10.1177/0022343317741535 |journal=Journal of Peace Research |language=en |volume=55 |issue=3 |pages=336–350 |doi=10.1177/0022343317741535 |s2cid=111399194 |issn=0022-3433))</ref> or if various social groups come together to cooperate about the shared challenge of climate change ([[environmental peacebuilding]]).<ref>((Cite journal |last1=Johnson |first1=McKenzie F. |last2=Rodríguez |first2=Luz A. |last3=Quijano Hoyos |first3=Manuela |date=2021-01-01 |title=Intrastate environmental peacebuilding: A review of the literature |url=https://www.sciencedirect.com/science/article/pii/S0305750X20302771 |journal=World Development |volume=137 |pages=105150 |doi=10.1016/j.worlddev.2020.105150 |s2cid=225171953 |issn=0305-750X))</ref><ref>((Cite journal |last1=Sändig |first1=Jan |last2=Dalmer |first2=Natalia |last3=Ide |first3=Tobias |last4=Vogler |first4=Anselm |date=2024-02-21 |title=From climate conflicts to environmental peacebuilding: Exploring local dimensions |url=http://journals.sagepub.com/doi/10.1177/27538796241231090 |journal=Environment and Security |language=en |doi=10.1177/27538796241231090 |issn=2753-8796|doi-access=free ))</ref>

===Economic impacts===
((Main|Economic analysis of climate change))[[File:The_share_of_firms_whose_business_activities_have_been_affected_by_climate_change.png|upright=1.35|thumb|Business activities affected by climate changed as found in the [[European Investment Bank]] Investment Survey 2020 ]]
Economic forecasts of the impact of global warming vary considerably. The impacts are worse if there is insufficient adaptation.<ref>((cite book |last1=Pörtner |first1=H.-O. |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Roberts |first2=D.C. |last3=Adams |first3=H. |last4=Adelekan |first4=I. |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |page=67 |chapter=Technical Summary |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_TechnicalSummary.pdf))</ref> Economic modelling may underrate the impact of catastrophic climatic changes. When estimating losses, economists choose a [[Time preference|discount rate]]. This determines how much one prefers to have goods or cash now compared to at a future date. Using a high discount rate may understate economic losses. This is because losses for future generations weigh less heavily.<ref>((Cite journal |last1=Kompas |first1=Tom |last2=Pham |first2=Van Ha |last3=Che |first3=Tuong Nhu |date=2018 |title=The Effects of Climate Change on GDP by Country and the Global Economic Gains From Complying With the Paris Climate Accord |journal=Earth's Future |volume=6 |issue=8 |pages=1153–1173 |bibcode=2018EaFut...6.1153K |doi=10.1029/2018EF000922 |doi-access=free |hdl=1885/265534 |hdl-access=free ))</ref>

Economic impacts are bigger the more the temperature rises.<ref>*((Cite book |author=IPCC |title=((Harvnb|IPCC AR5 WG2 A|2014)) |year=2014 |page=12 |chapter=Summary for Policymakers |ref=((harvid|IPCC AR5 WG2 Summary for Policymakers|2014)) |author-link=IPCC |access-date=15 February 2020 |chapter-url=https://archive.ipcc.ch/pdf/assessment-report/ar5/wg2/ar5_wgII_spm_en.pdf |archive-url=https://web.archive.org/web/20191219013825/https://archive.ipcc.ch/pdf/assessment-report/ar5/wg2/ar5_wgII_spm_en.pdf |archive-date=19 December 2019 |url-status=live))</ref> Scientists have compared impacts with warming of 1.5&nbsp;°C (2.7&nbsp;°F) and a level of 3.66&nbsp;°C (6.59&nbsp;°F). They use this higher figure to represent no efforts to stop emissions. They found that total damages at 1.5&nbsp;°C were 90% less than at 3.66&nbsp;°C.<ref name=":2" />((rp|256)) One study found that global GDP at the end of the century would be 3.5% less if warming is limited to ((Convert|3|C-change)). This study excludes the potential effect of [[Tipping points in the climate system|tipping points]]. Another study found that excluding tipping points underestimates the global economic impact by a factor of two to eight.<ref name=":2" />((rp|256)) Another study found that a temperature rise of ((Convert|2|C-change)) by 2050 would reduce global GDP by 2.5%–7.5%. By 2100 in this scenario the temperature would rise by ((Convert|4|C-change)). This could reduce global GDP by 30% in the worst case.<ref>((cite web |last1=Koning Beals |first1=Rachel |title=Global GDP will suffer at least a 3% hit by 2050 from unchecked climate change, say economists |url=https://www.marketwatch.com/story/global-gdp-will-suffer-at-least-a-3-hit-by-2050-from-unchecked-climate-change-say-economists-2019-11-20 |url-status=live |archive-url=https://web.archive.org/web/20200329094156/https://www.marketwatch.com/story/global-gdp-will-suffer-at-least-a-3-hit-by-2050-from-unchecked-climate-change-say-economists-2019-11-20 |archive-date=29 March 2020 |access-date=29 March 2020 |website=MarketWatch))</ref>

Global losses reveal rapidly rising costs due to extreme weather events since the 1970s.<ref name=":12" />((rp|110)) Socio-economic factors have contributed to the observed trend of global losses. These factors include population growth and increased wealth.<ref>((Citation |last=Bouwer |first=Laurens M. |title=Observed and Projected Impacts from Extreme Weather Events: Implications for Loss and Damage |date=2019 |work=Loss and Damage from Climate Change: Concepts, Methods and Policy Options |pages=63–82 |editor-last=Mechler |editor-first=Reinhard |series=Climate Risk Management, Policy and Governance |place=Cham |publisher=Springer International Publishing |doi=10.1007/978-3-319-72026-5_3 |isbn=978-3-319-72026-5 |editor2-last=Bouwer |editor2-first=Laurens M. |editor3-last=Schinko |editor3-first=Thomas |editor4-last=Surminski |editor4-first=Swenja |doi-access=free))</ref> Regional climatic factors also play a role. These include changes in precipitation and flooding events. It is difficult to quantify the relative impact of socio-economic factors and climate change on the observed trend.<ref name="disaster losses">((citation |author=IPCC |title=Synthesis Report |url=http://www.grida.no/climate/ipcc_tar/vol4/english/016.htm |archive-url=https://web.archive.org/web/20160305033232/http://www.grida.no/climate/ipcc_tar/vol4/english/016.htm |at=[http://www.grida.no/climate/ipcc_tar/vol4/english/025.htm Question 2, Sections 2.25 and 2.26] |access-date=21 June 2012 |archive-date=5 March 2016 |url-status=dead)), p. 55, ((harvnb|IPCC TAR SYR|2001)).</ref> The trend does suggest social systems are increasing vulnerable to climate change.<ref name="disaster losses" />

==== Economic inequality ====
[[File:20220712 Global economic damage due to greenhouse gas emissions - by country.svg|thumb|upright=1.35 | Rich nations have done the most to fuel climate change.<ref name="Guardian_20220712">Chart based on: ((cite news |last1=Milman |first1=Oliver |title=Nearly $2tn of damage inflicted on other countries by US emissions |url=https://www.theguardian.com/environment/2022/jul/12/us-carbon-emissions-greenhouse-gases-climate-crisis |newspaper=The Guardian |date=12 July 2022 |archive-url=https://web.archive.org/web/20220712091602/https://www.theguardian.com/environment/2022/jul/12/us-carbon-emissions-greenhouse-gases-climate-crisis |archive-date=12 July 2022 |url-status=live )) ''Guardian'' cites ((cite journal |last1=Callahan |first1=Christopher W. |last2=Mankin |first2=Justin S. |title=National attribution of historical climate damages |journal=Climatic Change |date=12 July 2022 |volume=172 |issue=40 |page=40 |doi=10.1007/s10584-022-03387-y |bibcode=2022ClCh..172...40C |s2cid=250430339 |doi-access=free )) Graphic's caption is from Callahan ''et al.''</ref>]]
Climate change has contributed to global economic inequality. Wealthy countries in colder regions have felt little overall economic impact from climate change or may have benefited. Poor hotter countries probably grew less than if there had been no global warming.<ref>((Cite journal|last1=Diffenbaugh|first1=Noah S.|last2=Burke|first2=Marshall|date=2019|title=Global warming has increased global economic inequality|journal=Proceedings of the National Academy of Sciences|volume=116|issue=20|pages=9808–9813|doi=10.1073/pnas.1816020116 |doi-access=free |pmid=31010922|pmc=6525504|bibcode=2019PNAS..116.9808D ))</ref><ref>((cite book |last1=Begum |first1=Rawshan Ara |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Lempert |first2=Robert |publisher=[[Intergovernmental Panel on Climate Change]] |series=Contribution of Working Group II to the [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |chapter=Chapter 1: Point of Departure and Key Concept |display-authors=etal |chapter-url=https://report.ipcc.ch/ar6wg2/pdf/IPCC_AR6_WGII_FinalDraft_Chapter01.pdf |at=Section 1.3.2.1 |access-date=5 March 2022 |archive-date=24 May 2022 |archive-url=https://web.archive.org/web/20220524204555/https://report.ipcc.ch/ar6wg2/pdf/IPCC_AR6_WGII_FinalDraft_Chapter01.pdf |url-status=dead ))</ref>

==== Highly affected sectors ====
Climate change has a bigger impact on economic sectors directly affected by weather than on other sectors.<ref name="TS54">((cite book |last1=Pörtner |first1=H.-O. |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Roberts |first2=D.C. |last3=Adams |first3=H. |last4=Adelekan |first4=I. |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |page=54 |chapter=Technical Summary |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_TechnicalSummary.pdf))</ref> It heavily affects agriculture, fisheries and forestry.<ref>((Cite web |title=Consequences of climate change |url=https://climate.ec.europa.eu/climate-change/consequences-climate-change_en |access-date=2023-04-15 |website=climate.ec.europa.eu |language=en))</ref> It also affects the tourism and energy sectors.<ref name="TS54" /> Agriculture and forestry have suffered economic losses due to droughts and extreme heat.<ref>((cite book |last1=Pörtner |first1=H.-O. |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Roberts |first2=D.C. |last3=Adams |first3=H. |last4=Adelekan |first4=I. |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |page=48 |chapter=Technical Summary |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_TechnicalSummary.pdf))</ref> If global warming goes over 1.5&nbsp;°C, there may be limits to how much tourism and outdoor work can adapt.<ref>((cite book |last1=Pörtner |first1=H.-O. |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Roberts |first2=D.C. |last3=Adams |first3=H. |last4=Adelekan |first4=I. |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |page=85 |chapter=Technical Summary |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_TechnicalSummary.pdf))</ref>

In the energy sector, thermal power plants depend on water to cool them. Climate change can increase the likelihood of drought and fresh water shortages. Higher operating temperatures make them less efficient. This reduces their output.<ref name="ODI1">Dr. Frauke Urban and Dr. Tom Mitchell 2011. [https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.825.4966&rep=rep1&type=pdf Climate change, disasters and electricity generation] ((webarchive|url=https://web.archive.org/web/20120920024704/http://www.odi.org.uk/resources/details.asp?id=5792&title=climate-change-disasters-electricity-generation|date=20 September 2012)). London: [[Overseas Development Institute]] and [[Institute of Development Studies]]</ref> Hydropower is affected by changes in the water cycle such as river flows. Diminished river flows can cause power shortages in areas that depend on hydroelectric power. Brazil relies on hydroelectricity. So it is particularly vulnerable. Rising temperatures, lower water flow, and changes in rainfall could reduce total energy production by 7% annually by the end of the century.<ref name="ODI1" /> Climate change affects oil and natural gas infrastructure. This is also vulnerable to the increased risk of disasters such as storms, cyclones, flooding and rising sea levels.<ref>((Cite web |last1=Nichols |first1=Will |last2=Clisby |first2=Rory |title=40% of Oil and Gas Reserves Threatened by Climate Change |url=https://www.maplecroft.com/insights/analysis/40-of-oil-and-gas-reserves-threatened-by-climate-change/ |access-date=15 February 2022 |website=Verisk Maplecroft ))</ref>

Global warming affects the insurance and financial services sectors.<ref name=":2" />((rp|212–213, 228, 252)) Insurance is an important tool to manage risks. But it is often unavailable to poorer households. Due to climate change, premiums are going up for certain types of insurance, such as flood insurance. Poor adaptation to climate change further widens the gap between what people can afford and the costs of insurance, as risks increase.<ref>((cite journal |last1=Surminski |first1=Swenja |last2=Bouwer |first2=Laurens M. |last3=Linnerooth-Bayer |first3=Joanne |title=How insurance can support climate resilience |journal=Nature Climate Change |date=April 2016 |volume=6 |issue=4 |pages=333–334 |doi=10.1038/nclimate2979 |bibcode=2016NatCC...6..333S |url=http://eprints.lse.ac.uk/65672/7/Nature%20Climate%20Change%206-2016.pdf ))</ref> In 2019 [[Munich Re]] said climate change could make home insurance unaffordable for households at or below average incomes.<ref>((cite web|url=https://www.theguardian.com/environment/2019/mar/21/climate-change-could-make-insurance-too-expensive-for-ordinary-people-report|title=Climate change could make insurance too expensive for most people – report|first=Arthur|last=Neslen|date=21 March 2019|access-date=22 March 2019|website=The Guardian))</ref>

It is possible that climate change has already begun to affect the [[shipping|shipping sector]] by impacting the [[Panama Canal]]. Lack of rainfall possibly linked to climate change reduced the number of ships passing through the canal per day, from 36 to 22 and by February 2024, it is expected to be 18.<ref>((cite news |last1=Yerushalmy |first1=Jonathan |title=Changing climate casts a shadow over the future of the Panama Canal – and global trade |url=https://www.theguardian.com/environment/2023/dec/22/changing-climate-casts-a-shadow-over-the-future-of-the-panama-canal-and-global-trade |access-date=28 December 2023 |agency=The Guardian |date=22 December 2023))</ref>

=== Social impacts on vulnerable groups ===
Climate change does not affect people within communities in the same way. It can have a bigger impact on vulnerable groups such as women, the elderly, religious minorities and refugees than on others.<ref>((cite book |last1=Begum |first1=Rawshan Ara |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Lempert |first2=Robert |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |chapter=Chapter 1: Point of Departure and Key Concept |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter01.pdf|page=170))</ref> 

* People living in poverty: Climate change disproportionally affects poor people in low-income communities and [[Developing country|developing countries]] around the world. Those in poverty have a higher chance of experiencing the ill-effects of climate change, due to their increased exposure and vulnerability.<ref name="Rayner">((cite journal |last=Rayner |first=S. and E.L. Malone |year=2001 |title=Climate Change, Poverty, and Intragernerational Equity: The National Leve |journal=International Journal of Global Environmental Issues |series=1 |volume=I |issue=2 |pages=175–202 |doi=10.1504/IJGENVI.2001.000977))</ref> A 2020 World Bank paper estimated that between 32 million to 132 million additional people will be pushed into extreme poverty by 2030 due to climate change.<ref>((Cite web |date=September 2020 |title=Revised Estimates of the Impact of Climate Change on Extreme Poverty by 2030 |url=http://documents1.worldbank.org/curated/en/706751601388457990/pdf/Revised-Estimates-of-the-Impact-of-Climate-Change-on-Extreme-Poverty-by-2030.pdf |access-date= ))</ref>
* Women: Climate change increases gender inequality.<ref name=":16">((cite journal |last1=Eastin |first1=Joshua |title=Climate change and gender equality in developing states |journal=World Development |date=1 July 2018 |volume=107 |pages=289–305 |doi=10.1016/j.worlddev.2018.02.021 |s2cid=89614518 ))</ref> It reduces women's ability to be financially independent,<ref name=":03">((Cite journal |last1=Goli |first1=Imaneh |last2=Omidi Najafabadi |first2=Maryam |last3=Lashgarara |first3=Farhad |date=9 March 2020 |title=Where are We Standing and Where Should We Be Going? Gender and Climate Change Adaptation Behavior |journal=Journal of Agricultural and Environmental Ethics |volume=33 |issue=2 |pages=187–218 |doi=10.1007/s10806-020-09822-3 |s2cid=216404045 ))</ref> and has an overall negative impact on the social and political rights of women. This is especially the case in economies that are heavily based on agriculture.<ref name=":16" />
* Indigenous peoples: Indigenous communities tend to rely more on the environment for food and other necessities. This makes them more vulnerable to disturbances in ecosystems.<ref>((cite book |last1=Pörtner |first1=H.-O. |title=Climate Change 2022: Impacts, Adaptation and Vulnerability |last2=Roberts |first2=D.C. |last3=Adams |first3=H. |last4=Adelekan |first4=I. |publisher=Cambridge University Press |series=The [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |page=47 |chapter=Technical Summary |display-authors=etal |chapter-url=https://ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_TechnicalSummary.pdf))</ref> Indigenous communities across the globe generally have bigger economic disadvantages than non-indigenous communities. This is due to the oppression they have experienced. These disadvantages include less access to education and jobs and higher rates of poverty. All this makes them more vulnerable to climate change.<ref name=":82">((Cite journal |last=Ford |first=James D. |date=17 May 2012 |title=Indigenous Health and Climate Change |journal=American Journal of Public Health |volume=102 |issue=7 |pages=1260–1266 |doi=10.2105/AJPH.2012.300752 |pmc=3477984 |pmid=22594718 ))</ref>
* Children: The Lancet review on health and climate change lists children among the worst-affected by global warming.<ref>((Cite journal |last1=Watts |first1=Nick |last2=Amann |first2=Markus |last3=Arnell |first3=Nigel |last4=Ayeb-Karlsson |first4=Sonja |last5=Belesova |first5=Kristine |last6=Boykoff |first6=Maxwell |last7=Byass |first7=Peter |last8=Cai |first8=Wenjia |last9=Campbell-Lendrum |first9=Diarmid |last10=Capstick |first10=Stuart |last11=Chambers |first11=Jonathan |date=16 November 2019 |title=The 2019 report of The Lancet Countdown on health and climate change: ensuring that the health of a child born today is not defined by a changing climate |journal=Lancet |volume=394 |issue=10211 |pages=1836–1878 |doi=10.1016/S0140-6736(19)32596-6 |pmid=31733928 |s2cid=207976337 |url=http://sro.sussex.ac.uk/id/eprint/88053/4/__smbhome.uscs.susx.ac.uk_tjk30_Documents_The%202019%20Report%20of%20the%20Lancet%20Countdown%20-%20revised.pdf ))</ref> Children are 14–44 percent more likely to die from environmental factors.<ref>((Cite journal |last1=Bartlett |first1=Sheridan |year=2008 |title=Climate change and urban children: Impacts and implications for adaptation in low- and middle-income countries |journal=Environment and Urbanization |volume=20 |issue=2 |pages=501–519 |doi=10.1177/0956247808096125 |bibcode=2008EnUrb..20..501B |s2cid=55860349))</ref>

=== Possibility of societal collapse ===
((Main|Climate change and civilizational collapse|Global catastrophe scenarios#Climate change))

Climate change has long been described as a severe risk to humans. Climate change as an ''existential threat'' has emerged as a key theme in the climate movement. People from [[Small island nation|small island nations]] also use this theme. There has not been extensive research in this topic. Existential risks are [[Extinction risk from climate change|threats that could cause the extinction of humanity]] or destroy the potential of intelligent life on Earth.<ref name=":24" /> Key risks of climate change do not fit that definition. However, some key climate risks do have an impact people's ability to survive. For instance, areas may become too hot to survive, or sea level rise may make it impossible to live at a specific location.<ref>((cite web |last1=Pester |first1=Patrick |title=Could climate change make humans go extinct? |url=https://www.livescience.com/climate-change-humans-extinct.html |website=Live Science |date=30 August 2021 |access-date=31 August 2021 |archive-date=30 August 2021 |archive-url=https://web.archive.org/web/20210830224155/https://www.livescience.com/climate-change-humans-extinct.html |url-status=live ))</ref><ref>((cite journal |last1=Steffen |first1=Will |last2=Persson |first2=Åsa |last3=Deutsch |first3=Lisa |last4=Zalasiewicz |first4=Jan |last5=Williams |first5=Mark |last6=Richardson |first6=Katherine |last7=Crumley |first7=Carole |last8=Crutzen |first8=Paul |last9=Folke |first9=Carl |last10=Gordon |first10=Line |last11=Molina |first11=Mario |last12=Ramanathan |first12=Veerabhadran |last13=Rockström |first13=Johan |last14=Scheffer |first14=Marten |last15=Schellnhuber |first15=Hans Joachim |last16=Svedin |first16=Uno |title=The Anthropocene: From Global Change to Planetary Stewardship |journal=Ambio |date=12 October 2011 |volume=40 |issue=7 |pages=739–761 |doi=10.1007/s13280-011-0185-x |pmid=22338713 |pmc=3357752 |bibcode=2011Ambio..40..739S ))</ref><ref name=":24">((Cite journal |last1=Huggel |first1=Christian |last2=Bouwer |first2=Laurens M. |last3=Juhola |first3=Sirkku |last4=Mechler |first4=Reinhard |last5=Muccione |first5=Veruska |last6=Orlove |first6=Ben |last7=Wallimann-Helmer |first7=Ivo |date=2022-09-12 |title=The existential risk space of climate change |url=https://doi.org/10.1007/s10584-022-03430-y |journal=Climatic Change |language=en |volume=174 |issue=1 |pages=8 |doi=10.1007/s10584-022-03430-y |issn=1573-1480 |pmc=9464613 |pmid=36120097|bibcode=2022ClCh..174....8H )) Text was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International License]</ref>

=== Long-term scenarios (up to 2500) ===
In 2021, researchers found that projecting effects of greenhouse gas emissions only for up to 2100, as widely practiced in research and [[Politics of climate change#Challenges|policy-making]], is short-sighted. They then modeled [[Representative Concentration Pathways|RCPs]], climate change scenarios and their effects for up to 2500.<ref>((cite news |date=14 October 2021 |title=By 2500 earth could be alien to humans |work=Scienmag: Latest Science and Health News |url=https://scienmag.com/by-2500-earth-could-be-alien-to-humans/ |access-date=18 October 2021))</ref><ref>((cite journal |last1=Lyon |first1=Christopher |last2=Saupe |first2=Erin E. |last3=Smith |first3=Christopher J. |last4=Hill |first4=Daniel J. |last5=Beckerman |first5=Andrew P. |last6=Stringer |first6=Lindsay C. |last7=Marchant |first7=Robert |last8=McKay |first8=James |last9=Burke |first9=Ariane |last10=O'Higgins |first10=Paul |last11=Dunhill |first11=Alexander M. |last12=Allen |first12=Bethany J. |last13=Riel-Salvatore |first13=Julien |last14=Aze |first14=Tracy |year=2021 |title=Climate change research and action must look beyond 2100 |journal=Global Change Biology |language=en |volume=28 |issue=2 |pages=349–361 |doi=10.1111/gcb.15871 |issn=1365-2486 |pmid=34558764 |s2cid=237616583 |doi-access=free|hdl=20.500.11850/521222 |hdl-access=free ))</ref>
[[File:Global mean near-surface air temperature and thermosteric sea-level rise anomalies relative to the 2000–2019 mean for RCP climate change scenarios.webp|center|thumb|600px|Global mean near-surface air temperature and thermosteric sea-level rise anomalies relative to the 2000–2019 mean for RCP scenarios]]

== See also ==
((portal|Climate change|Ecology|Environment|World))
* [[Anthropocene]]
* [[Climate crisis]]
* [[Extinction risk from climate change]]
* [[Global catastrophic risk]]
* [[History of climate change science]]
* [[Politics of climate change]]

((clear))

== References ==
((reflist|22em))

=== Sources ===
* ((Citation
| year   = 2007
| author = IPCC AR4 SYR
| author-link = IPCC
| title  = Climate Change 2007: Synthesis Report
| series = Contribution of Working Groups I, II and III to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change
| editor = Core Writing Team |editor2=Pachauri, R.K |editor3=Reisinger, A.
| publisher = IPCC
| location=[[Geneva]], [[Switzerland]]
| url  = http://archive.ipcc.ch/publications_and_data/ar4/syr/en/contents.html
| isbn = 978-92-9169-122-7
)).
* ((citation
 |author          = IPCC SREX
 |year            = 2012
 |title           = Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX)
 |editor         = Field, C.B.
 |url             = http://ipcc-wg2.gov/SREX/report/full-report/
 |publisher       = Cambridge University Press
 |display-editors = etal
 |url-status         = dead
 |archive-url      = https://web.archive.org/web/20121219055946/http://ipcc-wg2.gov/SREX/report/full-report/
 |archive-date     = 19 December 2012
)). Summary for Policymakers [http://archive.ipcc.ch/publications_and_data/publications_and_data_reports.shtml available] in Arabic, Chinese, French, Russian, and Spanish.

* ((citation
 | year=2013
 | author=IPCC AR5 WG1
 | editor=Stocker, T.F.| title=Climate Change 2013: The Physical Science Basis. Working Group 1 (WG1) Contribution to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5)
 | url=http://archive.ipcc.ch/report/ar5/wg1/
 | publisher=Cambridge University Press
|display-editors=etal)). [http://www.climatechange2013.org/ Climate Change 2013 Working Group 1 website.]

* ((citation
 |year=2014
 |author=IPCC AR5 WG2 A
 |editor=Field, C.B.
 |title=Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II (WG2) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC)
 |url=http://archive.ipcc.ch/report/ar5/wg2/
 |publisher=Cambridge University Press
 |display-editors=etal
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 |archive-url=https://web.archive.org/web/20140416051047/http://archive.ipcc.ch/report/ar5/wg2/
 |archive-date=16 April 2014
)). Archived

* ((Citation
 |year         = 2001
 |author       = IPCC TAR SYR
 |author-link  = IPCC
 |title        = Climate Change 2001: Synthesis Report
 |series       = Contribution of Working Groups I, II, and III to the [[IPCC Third Assessment Report|Third Assessment Report]] of the Intergovernmental Panel on Climate Change
 |editor1      = Watson, R. T.
 |editor2      = the Core Writing Team
 |publisher    = Cambridge University Press
 |url          = http://www.ipcc.ch/ipccreports/tar/vol4/english/index.htm
 |isbn         = 0-521-80770-0
 |access-date  = 2013-05-21
 |archive-date = 2018-11-03
 |archive-url  = https://web.archive.org/web/20181103153646/http://www.ipcc.ch/ipccreports/tar/vol4/english/index.htm
 |url-status   = dead
)) (pb: ((ISBNT|0-521-01507-3))).
* ((cite book |author=USGCRP |year=2017 |title=Climate Science Special Report: Fourth National Climate Assessment, Volume I |url=https://science2017.globalchange.gov/ |editor-last1=Wuebbles |editor1-first= D. J. |editor-last2=Fahey |editor2-first=D. W. |editor-last3=Hibbard |editor3-first=K. A. |editor-last4=Dokken |editor4-first=D. J. |editor-last5=Stewart |editor5-first=B. C. |editor-last6=Maycock |editor6-first=T. K. |display-editors=4 |location=Washington, D.C. |publisher=U.S. Global Change Research Program |doi=10.7930/J0J964J6))

== External links ==
((Commons category))

* [https://www.ipcc.ch/working-group/wg1/ IPCC Working Group I (WG I)]. [[Intergovernmental Panel on Climate Change]] group which assesses the physical scientific aspects of the climate system and climate change.
* [https://web.archive.org/web/20231215221733/https://public-old.wmo.int/en/our-mandate/climate Climate] from the [[World Meteorological Organization]]
* [https://sdgs.un.org/topics/climate-change Climate change] UN Department of Economic and Social Affairs Sustainable Development
* [https://www.metoffice.gov.uk/weather/climate-change/effects-of-climate-change Effects of climate change] from the [[Met Office]]
* [https://www.unep.org/unep-and-climate-emergency United Nations Environment Programme and the climate emergency]
*[http://www.zinnedproject.org/news/climate-crisis-has-a-history/ The Climate Crisis Has a History]. Timeline by Mimi Eisen and Ursula Wolfe-Rocca.

((Climate change|state=expanded))
((World topic|Climate change in|title=Climate change by country|noredlinks=yes|state=show))

[[Category:Climate change and society]]
[[Category:Health effects by subject|Glob]]
[[Category:Effects of climate change| ]]
[[Category:Holocene extinctions| ]]
[[Category:Regional effects of climate change| ]]
((Authority control))