Climate change in the Arctic

File: ArcticYearlongTempAnom HR.jpg

The period of 1995–2005 was the warmest decade in the Arctic since at least the 17th century, with temperatures {{convert|2|C-change|1}} above the 1951–1990 average.{{cite journal |last1=Przybylak |first1=Rajmund | year = 2007 | title = Recent air-temperature changes in the Arctic | journal = Annals of Glaciology | volume = 46 | issue = 1 | pages = 316–324 | doi = 10.3189/172756407782871666 | bibcode = 2007AnGla..46..316P | s2cid = 129155170 | doi-access = free }} Alaska and western Canada's temperature rose by {{convert|3|to|4|C-change|2}} during that period.Arctic Climate Impact Assessment (2004): Arctic Climate Impact Assessment. Cambridge University Press, {{ISBN|0-521-61778-2}}, siehe [http://www.acia.uaf.edu/pages/scientific.html online] {{Webarchive|url=https://web.archive.org/web/20130628144322/http://www.acia.uaf.edu/pages/scientific.html |date=28 June 2013 }} 2013 research has shown that temperatures in the region haven't been as high as they currently are since at least 44,000 years ago and perhaps as long as 120,000 years ago.[http://www.livescience.com/40676-arctic-temperatures-record-high.html Arctic Temperatures Highest in at Least 44,000 Years], Livescience, 24 October 2013{{Cite journal | last1 = Miller | first1 = G. H. | last2 = Lehman | first2 = S. J. | last3 = Refsnider | first3 = K. A. | last4 = Southon | first4 = J. R. | last5 = Zhong | first5 = Y. | title = Unprecedented recent summer warmth in Arctic Canada | doi = 10.1002/2013GL057188 | journal = Geophysical Research Letters | volume = 40 | issue = 21 | pages = 5745–5751 | year = 2013 | bibcode = 2013GeoRL..40.5745M | s2cid = 128849141 }} Since 2013, Arctic annual mean surface air temperature (SAT) has been at least {{convert|1|C-change|1}} warmer than the 1981-2010 mean.

In 2016, there were extreme anomalies from January to February with the temperature in the Arctic being estimated to be between {{convert|4-5.8|C-change|1}} more than it was between 1981 and 2010.{{cite journal |last1=Yu |first1=Yining |last2=Xiao |first2=Wanxin |last3=Zhang |first3=Zhilun |last4=Cheng |first4=Xiao |last5=Hui |first5=Fengming |last6=Zhao |first6=Jiechen |title=Evaluation of 2-m Air Temperature and Surface Temperature from ERA5 and ERA-I Using Buoy Observations in the Arctic during 2010–2020|journal=Remote Sensing |date=17 July 2021 |volume=13 |issue=Polar Sea Ice: Detection, Monitoring and Modeling|page=2813 |doi=10.3390/rs13142813 |bibcode=2021RemS...13.2813Y |doi-access=free }} In 2020, mean SAT was {{convert|1.9|C-change|1}} warmer than the 1981–2010 average.{{Cite web|title=Surface Air Temperature|url=https://arctic.noaa.gov/Report-Card/Report-Card-2020/ArtMID/7975/ArticleID/878/Surface-Air-Temperature|access-date=2021-05-18|website=Arctic Program|date=October 2020 |language=en-US}} On 20 June 2020, for the first time, a temperature measurement was made inside the Arctic Circle of 38 °C, more than 100 °F. This kind of weather was expected in the region only by 2100. In March, April and May the average temperature in the Arctic was {{convert|10|C-change|1}} higher than normal.{{cite news |last1=Rosane |first1=Olivia |title=A Siberian Town Just Hit 100 F Degrees |url=https://www.ecowatch.com/siberia-100-degrees-2646222137.html |access-date=23 June 2020 |agency=Ecowatch |date=22 June 2020}}{{cite news |last1=King |first1=Simon |last2=Rowlatt |first2=Justin |title=Arctic Circle sees 'highest-ever' recorded temperatures |url=https://www.bbc.com/news/science-environment-53140069 |access-date=23 June 2020 |agency=BBC |date=22 June 2020}} This heat wave, without human – induced warming, could happen only one time in 80,000 years, according to an attribution study published in July 2020. It is the strongest link of a weather event to anthropogenic climate change that had been ever found, for now.{{cite news |last1=Rowlatt |first1=Justin |title=Climate change: Siberian heatwave 'clear evidence' of warming |url=https://www.bbc.com/news/science-environment-53415297 |access-date=17 July 2020 |agency=BBC |date=15 July 2020}}

File:Wunderling_2020_regional_impact.jpg

{{excerpt|Ice–albedo feedback#Current role|file=no}}

{{excerpt|Polar amplification#Recent Arctic amplification|paragraphs=2-3}}

An observed impact of climate change is a strong increase in the number of lightnings in the Arctic. Lightnings increase the risk for wildfires.{{cite news |last1=Chao-Fong |first1=Léonie |title='Drastic' rise in high Arctic lightning has scientists worried |url=https://www.theguardian.com/environment/2022/jan/07/lightning-high-arctic-rise-scientists-worried |access-date=30 January 2022 |agency=The Guardian |date=7 January 2021}} Some research suggests that globally, a warming greater than {{convert|1.5|C-change|1}} over the preindustrial level could change the type of precipitation in the Arctic from snow to rain in summer and autumn.

File:Slater 2021 global ice loss.png Material was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International License]|bibcode=2021TCry...15..233S |hdl=20.500.11820/df343a4d-6b66-4eae-ac3f-f5a35bdeef04 |hdl-access=free }}]]

File:Seaice-1870-part-2009.png in million square kilometers. Blue shading indicates the pre-satellite era; data then is less reliable.]]{{excerpt|Arctic sea ice decline|paragraphs=1-2|file=no}}

File:Beckmann 2023 Greenland 2300 RCP85 extent.png

{{excerpt|Greenland ice sheet|paragraphs=2-4|file=no}}

A January 2025 study published in the Proceedings of the National Academy of Sciences reported an "abrupt, coherent, climate-driven transformation" from "blue" (more transparent) to "brown" (less transparent) states of lakes in Greenland after a season of both record heat and rainfall drove a state change in these systems. This change was said to alter "numerous physical, chemical, and biological lake features", and the state changes were said to be unprecedented.{{cite journal |last1=Saros |first1=Jasmine E. |last2=Hazukova |first2=Vaclava |last3=Northington |first3=Robert M. |last4=McGowan |first4=Suzanne |title=Abrupt transformation of West Greenland lakes following compound climate extremes associated with atmospheric rivers |journal=Proceedings of the National Academy of Sciences of the United States of America |date=21 January 2025 |volume=122 |issue=4 |page=e2413855122 |doi=10.1073/pnas.241385512}}

File:Arctic Vegetation Index Trend (WH).png

File:Arctic Vegetation Index Trend (EH).png

Climate change is expected to have a strong effect on the Arctic's flora, some of which is already being seen.{{Cite journal|last1=Bjorkman|first1=Anne D.|last2=García Criado|first2=Mariana|last3=Myers-Smith|first3=Isla H.|last4=Ravolainen|first4=Virve|last5=Jónsdóttir|first5=Ingibjörg Svala|last6=Westergaard|first6=Kristine Bakke|last7=Lawler|first7=James P.|last8=Aronsson|first8=Mora|last9=Bennett|first9=Bruce|last10=Gardfjell|first10=Hans|last11=Heiðmarsson|first11=Starri|date=2019-03-30|title=Status and trends in Arctic vegetation: Evidence from experimental warming and long-term monitoring|url=http://dx.doi.org/10.1007/s13280-019-01161-6|journal=Ambio|volume=49|issue=3|pages=678–692|doi=10.1007/s13280-019-01161-6|issn=0044-7447|pmc=6989703|pmid=30929249}} NASA and NOAA have continuously monitored Arctic vegetation with satellite instruments such as Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced very-high-resolution radiometer (AVHRR).{{Cite journal|last=Gutman|first=G.Garik|date=February 1991|title=Vegetation indices from AVHRR: An update and future prospects|url=http://dx.doi.org/10.1016/0034-4257(91)90005-q|journal=Remote Sensing of Environment|volume=35|issue=2–3|pages=121–136|bibcode=1991RSEnv..35..121G|doi=10.1016/0034-4257(91)90005-q|issn=0034-4257}} Their data allows scientists to calculate so-called "Arctic greening" and "Arctic browning".{{Cite book|last=Sonja|first=Myers-Smith, Isla H. Kerby, Jeffrey T. Phoenix, Gareth K. Bjerke, Jarle W. Epstein, Howard E. Assmann, Jakob J. John, Christian Andreu-Hayles, Laia Angers-Blondin, Sandra Beck, Pieter S. A. Berner, Logan T. Bhatt, Uma S. Bjorkman, Anne D. Blok, Daan Bryn, Anders Christiansen, Casper T. Cornelissen, J. Hans C. Cunliffe, Andrew M. Elmendorf, Sarah C. Forbes, Bruce C. Goetz, Scott J. Hollister, Robert D. de Jong, Rogier Loranty, Michael M. Macias-Fauria, Marc Maseyk, Kadmiel Normand, Signe Olofsson, Johan Parker, Thomas C. Parmentier, Frans-Jan W. Post, Eric Schaepman-Strub, Gabriela Stordal, Frode Sullivan, Patrick F. Thomas, Haydn J. D. Tommervik, Hans Treharne, Rachael Tweedie, Craig E. Walker, Donald A. Wilmking, Martin Wipf|url=http://worldcat.org/oclc/1234747430|title=Complexity revealed in the greening of the Arctic|date=2020|publisher=Umeå universitet, Institutionen för ekologi, miljö och geovetenskap|oclc=1234747430}} From 1985 to 2016, greening has occurred in 37.3% of all sites sampled in the tundra, whereas browning was observed only in 4.7% of the sites - typically the ones that were still experiencing cooling and drying, as opposed to warming and wettening for the rest.{{Cite journal|last1=Berner|first1=Logan T.|last2=Massey|first2=Richard|last3=Jantz|first3=Patrick|last4=Forbes|first4=Bruce C.|last5=Macias-Fauria|first5=Marc|last6=Myers-Smith|first6=Isla|last7=Kumpula|first7=Timo|last8=Gauthier|first8=Gilles|last9=Andreu-Hayles|first9=Laia|last10=Gaglioti|first10=Benjamin V.|last11=Burns|first11=Patrick|date=December 2020|title=Summer warming explains widespread but not uniform greening in the Arctic tundra biome|journal=Nature Communications|language=en|volume=11|issue=1|pages=4621|bibcode=2020NatCo..11.4621B|doi=10.1038/s41467-020-18479-5|issn=2041-1723|pmc=7509805|pmid=32963240}}

This expansion of vegetation in the Arctic is not equivalent across types of vegetation. A major trend has been from shrub-type plants taking over areas previously dominated by moss and lichens. This change contributes to the consideration that the tundra biome is currently experiencing the most rapid change of any terrestrial biomes on the planet.{{Cite journal|last1=Martin|first1=Andrew|last2=Petrokofsky|first2=Gillian|date=2018-05-24|title=Shrub growth and expansion in the Arctic tundra: an assessment of controlling factors using an evidence-based approach.|url=http://dx.doi.org/10.17011/conference/eccb2018/108642|journal=Proceedings of the 5th European Congress of Conservation Biology|location=Jyväskylä|publisher=Jyvaskyla University Open Science Centre|doi=10.17011/conference/eccb2018/108642|s2cid=134164370 }}{{Cite journal|last1=Myers-Smith|first1=Isla H.|last2=Hik|first2=David S.|date=2017-09-25|title=Climate warming as a driver of tundra shrubline advance|url=http://dx.doi.org/10.1111/1365-2745.12817|journal=Journal of Ecology|volume=106|issue=2|pages=547–560|doi=10.1111/1365-2745.12817|issn=0022-0477|hdl=20.500.11820/f12e7d9d-1c24-4b5f-ad86-96715e071c7b|s2cid=90390767}} The direct impact on mosses and lichens is unclear as there exist very few studies at species level, but climate change is more likely to cause increased fluctuation and more frequent extreme events.{{Cite journal|last1=Alatalo|first1=Juha M.|last2=Jägerbrand|first2=Annika K.|last3=Molau|first3=Ulf|date=2014-08-14|title=Climate change and climatic events: community-, functional- and species-level responses of bryophytes and lichens to constant, stepwise, and pulse experimental warming in an alpine tundra|url=http://dx.doi.org/10.1007/s00035-014-0133-z|journal=Alpine Botany|volume=124|issue=2|pages=81–91|doi=10.1007/s00035-014-0133-z|bibcode=2014AlBot.124...81A |issn=1664-2201|s2cid=6665119}} While shrubs may increase in range and biomass, warming may also cause a decline in cushion plants such as moss campion, and since cushion plants act as facilitator species across trophic levels and fill important ecological niches in several environments, this could cause cascading effects in these ecosystems that could severely affect the way in which they function and are structured.{{Cite journal|last1=Alatalo|first1=Juha M|last2=Little|first2=Chelsea J|date=2014-03-22|title=Simulated global change: contrasting short and medium term growth and reproductive responses of a common alpine/Arctic cushion plant to experimental warming and nutrient enhancement|journal=SpringerPlus|volume=3|issue=1|page=157|doi=10.1186/2193-1801-3-157|issn=2193-1801|pmc=4000594|pmid=24790813 |doi-access=free }}

The expansion of these shrubs can also have strong effects on other important ecological dynamics, such as the albedo effect.{{Cite journal|last1=Loranty|first1=Michael M|last2=Goetz|first2=Scott J|last3=Beck|first3=Pieter S A|date=2011-04-01|title=Tundra vegetation effects on pan-Arctic albedo|url=http://dx.doi.org/10.1088/1748-9326/6/2/024014|journal=Environmental Research Letters|volume=6|issue=2|pages=024014|bibcode=2011ERL.....6b4014L|doi=10.1088/1748-9326/6/2/024014|s2cid=250681995 |issn=1748-9326}} These shrubs change the winter surface of the tundra from undisturbed, uniform snow to mixed surface with protruding branches disrupting the snow cover,{{Cite journal|last1=Belke-Brea|first1=M.|last2=Domine|first2=F.|last3=Barrere|first3=M.|last4=Picard|first4=G.|last5=Arnaud|first5=L.|date=2020-01-15|title=Impact of Shrubs on Winter Surface Albedo and Snow Specific Surface Area at a Low Arctic Site: In Situ Measurements and Simulations|url=http://dx.doi.org/10.1175/jcli-d-19-0318.1|journal=Journal of Climate|volume=33|issue=2|pages=597–609|bibcode=2020JCli...33..597B|doi=10.1175/jcli-d-19-0318.1|s2cid=210295151|issn=0894-8755}} this type of snow cover has a lower albedo effect, with reductions of up to 55%, which contributes to a positive feedback loop on regional and global climate warming. This reduction of the albedo effect means that more radiation is absorbed by plants, and thus, surface temperatures increase, which could disrupt current surface-atmosphere energy exchanges and affect thermal regimes of permafrost. Carbon cycling is also being affected by these changes in vegetation, as parts of the tundra increase their shrub cover, they behave more like boreal forests in terms of carbon cycling.{{Cite journal|last1=Jeong|first1=Su-Jong|last2=Bloom|first2=A. Anthony|last3=Schimel|first3=David|last4=Sweeney|first4=Colm|last5=Parazoo|first5=Nicholas C.|last6=Medvigy|first6=David|last7=Schaepman-Strub|first7=Gabriela|last8=Zheng|first8=Chunmiao|last9=Schwalm|first9=Christopher R.|last10=Huntzinger|first10=Deborah N.|last11=Michalak|first11=Anna M.|date=July 2018|title=Accelerating rates of Arctic carbon cycling revealed by long-term atmospheric CO 2 measurements|url=http://dx.doi.org/10.1126/sciadv.aao1167|journal=Science Advances|volume=4|issue=7|pages=eaao1167|bibcode=2018SciA....4.1167J|doi=10.1126/sciadv.aao1167|issn=2375-2548|pmc=6040845|pmid=30009255}} This is speeding up the carbon cycle, as warmer temperatures lead to increased permafrost thawing and carbon release, but also carbon capturing from plants that have increased growth. It is not certain whether this balance will go in one direction or the other, but studies have found that it is more likely that this will eventually lead to increased {{CO2}} in the atmosphere.

However, boreal forests, particularly those in North America, showed a different response to warming. Many boreal forests greened, but the trend was not as strong as it was for tundra of the circumpolar Arctic, mostly characterized by shrub expansion and increased growth.{{Cite journal|last1=Martin|first1=Andrew C.|last2=Jeffers|first2=Elizabeth S.|last3=Petrokofsky|first3=Gillian|last4=Myers-Smith|first4=Isla|last5=Macias-Fauria|first5=Marc|date=August 2017|title= Shrub growth and expansion in the Arctic tundra: An assessment of controlling factors using an evidence-based approach|url=https://iopscience.iop.org/article/10.1088/1748-9326/aa7989|journal=Environmental Research Letters|language=en|volume=12|issue=8|page=085007|doi=10.1088/1748-9326/aa7989|bibcode=2017ERL....12h5007M|s2cid=134164370 }} In North America, some boreal forests actually experienced browning over the study period. Droughts, increased forest fire activity, animal behavior, industrial pollution, and a number of other factors may have contributed to browning.

File:Polar Bear Habitat.png

Arctic warming negatively affects the foraging and breeding ecology of native Arctic mammals, such as Arctic foxes or Arctic reindeer.{{Cite journal|last1=Descamps|first1=Sébastien|last2=Aars|first2=Jon|last3=Fuglei|first3=Eva|last4=Kovacs|first4=Kit M.|last5=Lydersen|first5=Christian|last6=Pavlova|first6=Olga|last7=Pedersen|first7=Åshild Ø.|last8=Ravolainen|first8=Virve|last9=Strøm|first9=Hallvard|date=2016-06-28|title=Climate change impacts on wildlife in a High Arctic archipelago – Svalbard, Norway|url=http://dx.doi.org/10.1111/gcb.13381|journal=Global Change Biology|volume=23|issue=2|pages=490–502|doi=10.1111/gcb.13381|issn=1354-1013|pmid=27250039|s2cid=34897286}} In July 2019, 200 Svalbard reindeer were found starved to death apparently due to low precipitation related to climate change.[https://www.livescience.com/66047-200-dead-reindeer-norway.html More Than 200 Reindeer Found Dead in Norway, Starved by Climate Change] By Mindy Weisberger. Live Science, 29 July 2019 This was only one episode in the long-term decline of the species.{{rp|2327}} United States Geological Survey research suggests that the shrinkage of Arctic sea ice would eventually extirpate polar bears from Alaska, but leave some of their habitat in the Canadian Arctic Archipelago and areas off the northern Greenland coast.{{cite web|last=DeWeaver|first=Eric|author2=U.S. Geological Survey|year=2007|title=Uncertainty in Climate Model Projections of Arctic Sea Ice Decline: An Evaluation Relevant to Polar Bears|url=http://www.usgs.gov/newsroom/special/polar_bears/docs/USGS_PolarBear_DeWeaver_GCM-Uncertainty.pdf|url-status=dead|archive-url=https://web.archive.org/web/20090509072101/http://www.usgs.gov/newsroom/special/polar_bears/docs/USGS_PolarBear_DeWeaver_GCM-Uncertainty.pdf|archive-date=9 May 2009|publisher=United States Department of the Interior|oclc=183412441|df=dmy-all}}{{cite news|last=Broder|first=John|author2=Revkin, Andrew C.|date=8 July 2007|title=Warming Is Seen as Wiping Out Most Polar Bears|work=The New York Times|url=https://www.nytimes.com/2007/09/08/science/earth/08polar.html?_r=1&hp=&adxnnl=1&oref=slogin&adxnnlx=1190574637-aS0VOr2klykTSNwK91tiDg|access-date=23 September 2007}}

As the pure Arctic climate is gradually replaced by the subarctic climate, animals adapted to those conditions spread to the north.{{rp|2325}} For instance, beavers have been actively colonizing Arctic regions, and as they create dams, they flood areas which used to be permafrost, contributing to its thaw and methane emissions from it.{{Cite journal |last1=Clark |first1=Jason A |last2=Tape |first2=Ken D |last3=Baskaran |first3=Latha |last4=Elder |first4=Clayton |last5=Miller |first5=Charles |last6=Miner |first6=Kimberley |last7=O'Donnell |first7=Jonathan A |last8=Jones |first8=Benjamin M |date=3 July 2023 |title=Do beaver ponds increase methane emissions along Arctic tundra streams? |journal=Environmental Research Letters |language=en |volume=18 |issue=7 |doi=10.1088/1748-9326/acde8e |bibcode=2023ERL....18g5004C }} These colonizing species can outright replace native species, and they may also interbreed with their southern relations, like in the case of the Grizzly–polar bear hybrid. This usually has the effect of reducing the genetic diversity of the genus. Infectious diseases, such as brucellosis or phocine distemper virus, may spread to populations previously separated by the cold, or, in case of the marine mammals, the sea ice.{{cite web|last=Struzik|first=Ed|date=14 February 2011|title=Arctic Roamers: The Move of Southern Species into Far North|url=http://e360.yale.edu/feature/arctic_roamers_the_move_of_southern_species_into_far_north/2370/|access-date=19 July 2016|website=Environment360|publisher=Yale University|quote=Grizzly bears mating with polar bears. Red foxes out-competing Arctic foxes. Exotic diseases making their way into once-isolated polar realms. These are just some of the worrisome phenomena now occurring as Arctic temperatures soar and the Arctic Ocean, a once-impermeable barrier, melts.}}

File:NASA Arctic chlorophyll increase.png Earth Observatory |language=en |access-date=25 May 2024 }}]]

The reduction of sea ice has brought more sunlight to the phytoplankton and increased the annual marine primary production in the Arctic by over 30% between 1998 and 2020.{{rp|2327}} As the result, the Arctic Ocean became a stronger carbon sink over this period;{{Cite journal |last1=Yasunaka |first1=Sayaka |last2=Manizza |first2=Manfredi |last3=Terhaar |first3=Jens |last4=Olsen |first4=Are |last5=Yamaguchi |first5=Ryohei |last6=Landschützer |first6=Peter |last7=Watanabe |first7=Eiji |last8=Carroll |first8=Dustin |last9=Adiwira |first9=Hanani |last10=Müller |first10=Jens Daniel |last11=Hauck |first11=Judith |date=10 November 2023 |title=An Assessment of CO2 Uptake in the Arctic Ocean From 1985 to 2018 |journal=Global Biogeochemical Cycles |volume=37 |issue=11 |page=e2023GB007806 |doi=10.1029/2023GB007806 }} yet, it still accounts for only 5% to 14% of the total ocean carbon sink, although it is expected to play a larger role in the future.{{cite journal |last1=Richaud |first1=Benjamin |last2=Fennel |first2=Katja |last3=Oliver |first3=Eric C. J. |last4=DeGrandpre |first4=Michael D. |last5=Bourgeois |first5=Timothée |last6=Hu |first6=Xianmin |last7=Lu |first7=Youyu |title=Underestimation of oceanic carbon uptake in the Arctic Ocean: ice melt as predictor of the sea ice carbon pump |date=11 July 2023 |journal=The Cryosphere |volume=17 |issue=7 |pages=2665–2680 |doi=10.5194/tc-17-2665-2023 |doi-access=free |bibcode=2023TCry...17.2665R }} By 2100, phytoplankton biomass in the Arctic Ocean is generally expected to increase by ~20% relative to 2000 under the low-emission scenario, and by 30-40% under the high-emission scenario.{{rp|2329}}

Atlantic cod have been able to move deeper into the Arctic due to the warming waters, while the Polar cod and local marine mammals have been losing habitat.{{rp|2327}} Many copepod species appear to be declining, which is also likely to reduce the numbers of fish which prey on them, such as walleye pollock or the arrowtooth flounder.{{rp|2327}} This also affects Arctic shorebirds. For instance, around 9000 puffins and other shorebirds in Alaska died of starvation in 2016, because too many fish have moved to the north.{{Cite web|date=30 May 2019 |author=Helen Briggs|title=Climate change link to puffin deaths |url=https://www.bbc.com/news/science-environment-48447394|access-date=25 June 2023|website=BBC News|language=en}} While the shorebirds also appear to nest more successfully due to the observed warming,{{cite journal|author1=Weiser, E.L.|author2=Brown, S.C.|author3=Lanctot, R.B.|author4=River Gates, H.|author5=Abraham, K.F.|author6=Bentzen, R.L.|author7=Bêty, J.|author8=Boldenow, M.L.|author9=Brook, R.W.|author10=Donnelly, T.F.|author11=English, W.B.|display-authors=5|year=2018|title=Effects of environmental conditions on reproductive effort and nest success of Arctic-breeding shorebirds|journal=Ibis|volume=160|issue=3|pages=608–623|doi=10.1111/ibi.12571|hdl-access=free|author20=Kwon, E.|author35=Solovyeva, D.|hdl=10919/99313|author12=Flemming, S.A.|author13=Franks, S.E.|author14=Gilchrist, H.G.|author15=Giroux, M.|author16=Johnson, A.|author17=Kendall, S.|author18=Kennedy, L.V.|s2cid=53514207|author38=Sandercock, B.K.|author37=Woodard, P.F.|author36=Ward, D.H.|author34=Soloviev, M.|author21=Lamarre, J.|author33=Smith, P.A.|author32=Senner, N.R.|author31=Saalfeld, S.T.|author30=Robards, M.|author29=Rausch, J.|author28=Perz, J.|author27=Nol, E.|author26=McKinnon, L.|author25=Liebezeit, J.R.|author19=Koloski, L.|author23=Latty, C.J.|author22=Lank, D.B.|author24=Lecomte, N.}} this benefit may be more than offset by phenological mismatch between shorebirds' and other species' life cycles.{{Cite journal|last1=Saalfeld|first1=Sarah T.|last2=Hill|first2=Brooke L. |last3=Hunter|first3=Christine M. |last4=Frost|first4=Charles J.|last5=Lanctot|first5=Richard B.|date=27 July 2021|title=Warming Arctic summers unlikely to increase productivity of shorebirds through renesting|journal=Scientific Reports|volume=11|issue=1 |page=15277 |doi=10.1038/s41598-021-94788-z |pmid=34315998 |pmc=8316457 |doi-access=free|bibcode=2021NatSR..1115277S }} Marine mammals such as ringed seals and walruses are also being negatively affected by the warming.{{Cite web|title=Walruses in a Time of Climate Change|url=https://www.arctic.noaa.gov/Report-Card/Report-Card-2015/ArtMID/5037/ArticleID/226/Walruses-in-a-Time-of-Climate-Change|access-date=2021-05-19|website=Arctic Program|date=14 July 2016 |language=en-US}}

{{See also|Arctic methane emissions}}

In 2024, the Arctic has transformed from a carbon sink to a carbon source due to the impacts of climate change, mainly rising temperatures and wildfires.{{cite web |title=Arctic tundra becoming source of carbon dioxide emissions |url=https://www.noaa.gov/news-release/arctic-tundra-becoming-source-of-carbon-dioxide-emissions |website=NOAA logo National Oceanic and Atmospheric Administration |access-date=22 December 2024}}

File:Permafrost thaw ponds in Hudson Bay Canada near Greenland.jpg]]

Permafrost is an important component of hydrological systems and ecosystems within the Arctic landscape.{{Cite web|title=Terrestrial Permafrost|url=https://arctic.noaa.gov/Report-Card/Report-Card-2017/ArtMID/7798/ArticleID/694/Terrestrial-Permafrost|access-date=2021-05-18|website=Arctic Program|date=24 October 2017 |language=en-US}} In the Northern Hemisphere the terrestrial permafrost domain comprises around 18 million km².{{Cite journal|last1=Sayedi|first1=Sayedeh Sara|last2=Abbott|first2=Benjamin W|last3=Thornton|first3=Brett F|last4=Frederick|first4=Jennifer M|last5=Vonk|first5=Jorien E|last6=Overduin|first6=Paul|last7=Schädel|first7=Christina|last8=Schuur|first8=Edward A G|last9=Bourbonnais|first9=Annie|last10=Demidov|first10=Nikita|last11=Gavrilov|first11=Anatoly|date=2020-12-01|title=Subsea permafrost carbon stocks and climate change sensitivity estimated by expert assessment|url=http://dx.doi.org/10.1088/1748-9326/abcc29|journal=Environmental Research Letters|volume=15|issue=12|pages=B027-08|doi=10.1088/1748-9326/abcc29|bibcode=2020AGUFMB027...08S|s2cid=234515282|issn=1748-9326}} Within this permafrost region, the total soil organic carbon (SOC) stock is estimated to be 1,460-1,600 Pg (where 1 Pg = 1 billion tons), which constitutes double the amount of carbon currently contained in the atmosphere.{{Cite journal|last1=Hugelius|first1=G.|last2=Strauss|first2=J.|last3=Zubrzycki|first3=S.|last4=Harden|first4=J. W.|author-link4=Jennifer Harden|last5=Schuur|first5=E. A. G.|last6=Ping|first6=C.-L.|last7=Schirrmeister|first7=L.|last8=Grosse|first8=G.|last9=Michaelson|first9=G. J.|last10=Koven|first10=C. D.|last11=O'Donnell|first11=J. A.|date=2014-12-01|title=Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps|journal=Biogeosciences|volume=11|issue=23|pages=6573–6593|doi=10.5194/bg-11-6573-2014|bibcode=2014BGeo...11.6573H|s2cid=14158339 |issn=1726-4189 |doi-access=free }}{{Cite web|title=Permafrost and the Global Carbon Cycle|url=https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle|access-date=2021-05-18|website=Arctic Program|date=31 October 2019 |language=en-US}}

{{excerpt|Permafrost#Climate change feedback|paragraphs=1-2|file=no}}

{{excerpt|Permafrost#Impact on global temperatures|hat=no}}

File:Winiger 2016 black carbon.jpg{{Cite journal|last1=Winiger |first1=P |last2=Andersson |first2=A |last3=Stohl |first3=A |last4=Gustafsson |first4=Ö. |date= 15 September 2016 |title=The sources of atmospheric black carbon at a European gateway to the Arctic |journal=Nature Communications |volume=7 |issue=1 |page=12776 |doi=10.1038/ncomms12776 |bibcode=2016NatCo...712776W }} ]]

{{Main|Black carbon}}

Black carbon deposits (from the combustion of heavy fuel oil (HFO) of Arctic shipping) absorb solar radiation in the atmosphere and strongly reduce the albedo when deposited on snow and ice, thus accelerating the effect of the melting of snow and sea ice.{{Cite journal|last1=Qi|first1=Ling|last2=Wang|first2=Shuxiao|date=November 2019|title=Sources of black carbon in the atmosphere and in snow in the Arctic|url=http://dx.doi.org/10.1016/j.scitotenv.2019.07.073|journal=Science of the Total Environment|volume=691|pages=442–454|doi=10.1016/j.scitotenv.2019.07.073|pmid=31323589|bibcode=2019ScTEn.691..442Q|s2cid=198135020|issn=0048-9697}} A 2013 study quantified that gas flaring at petroleum extraction sites contributed over 40% of the black carbon deposited in the Arctic.{{Citation |author=Stohl, A. |author2=Klimont, Z. |author3=Eckhardt, S. |author4=Kupiainen, K. |author5=Chevchenko, V.P. |author6=Kopeikin, V.M. |author7=Novigatsky, A.N. |title=Black carbon in the Arctic: the underestimated role of gas flaring and residential combustion emissions |journal=Atmos. Chem. Phys. |volume=13 |issue=17 |pages=8833–8855 |year=2013 |doi=10.5194/acp-13-8833-2013 |bibcode=2013ACP....13.8833S |doi-access=free }}{{Cite web |url=https://arctic-council.org/images/PDF_attachments/COP24_2018/2018-11-10-COP24-Stanley-flaring-World-Bank-BC.pdf |title=Gas flaring: An industry practice faces increasing global attention |first=Michael |last=Stanley |publisher=World Bank |date=2018-12-10 |access-date=2020-01-20 |archive-date=15 February 2019 |archive-url=https://web.archive.org/web/20190215231453/https://www.arctic-council.org/images/PDF_attachments/COP24_2018/2018-11-10-COP24-Stanley-flaring-World-Bank-BC.pdf |url-status=dead }} 2019 research attributed the majority (56%) of Arctic surface black carbon to emissions from Russia, followed by European emissions, and Asia also being a large source.{{Cite journal|last1=Zhu|first1=Chunmao|last2=Kanaya|first2=Yugo|last3=Takigawa|first3=Masayuki|last4=Ikeda|first4=Kohei|last5=Tanimoto|first5=Hiroshi|last6=Taketani|first6=Fumikazu|last7=Miyakawa|first7=Takuma|last8=Kobayashi|first8=Hideki|last9=Pisso|first9=Ignacio|title=Flexpart v10.1 simulation of source contributions to Arctic black carbon|date=2019-09-24|journal=Atmospheric Chemistry and Physics |doi=10.5194/acp-2019-590|s2cid=204117555 |doi-access=free }} In 2015, research suggested that reducing black carbon emissions and short-lived greenhouse gases by roughly 60 percent by 2050 could cool the Arctic up to 0.2 °C.{{cite web|url=http://www.climatecentral.org/news/race-to-understand-black-carbons-climate-impact-21458|title=The Race to Understand Black Carbon's Climate Impact|publisher=ClimateCentral|year=2017|access-date=21 May 2017|archive-date=22 November 2017|archive-url=https://web.archive.org/web/20171122113008/http://www.climatecentral.org/news/race-to-understand-black-carbons-climate-impact-21458|url-status=dead}} However, a 2019 study indicates that "Black carbon emissions will continuously rise due to increased shipping activities", specifically fishing vessels.{{Cite journal|last1=Zhang|first1=Qiang|last2=Wan|first2=Zheng|last3=Hemmings|first3=Bill|last4=Abbasov|first4=Faig|date=December 2019|title=Reducing black carbon emissions from Arctic shipping: Solutions and policy implications|url=http://dx.doi.org/10.1016/j.jclepro.2019.118261|journal=Journal of Cleaner Production|volume=241|pages=118261|doi=10.1016/j.jclepro.2019.118261|bibcode=2019JCPro.24118261Z |s2cid=203303955|issn=0959-6526}}

The number of wildfires in the Arctic Circle has increased. In 2020, Arctic wildfire {{CO2}} emissions broke a new record, peaking at 244 megatonnes of carbon dioxide emitted.{{Cite journal|last=Witze|first=Alexandra|date=2020-09-10|title=The Arctic is burning like never before — and that's bad news for climate change|url=http://dx.doi.org/10.1038/d41586-020-02568-y|journal=Nature|volume=585|issue=7825|pages=336–337|bibcode=2020Natur.585..336W|doi=10.1038/d41586-020-02568-y|issn=0028-0836|pmid=32913318|s2cid=221625701}}  This is due to the burning of peatlands, carbon-rich soils that originate from the accumulation of waterlogged plants which are mostly found at Arctic latitudes. These peatlands are becoming more likely to burn as temperatures increase, but their own burning and releasing of {{CO2}} contributes to their own likelihood of burning in a positive feedback loop.The smoke from wildfires defined as "brown carbon" also increases arctic warming, with its warming effect is around 30% that of black carbon. As wildfires increases with warming this creates a positive feedback loop.

{{excerpt|Clathrate gun hypothesis|paragraphs=1}}

{{excerpt|Clathrate gun hypothesis#Current outlook|paragraphs=2-3|hat=no}}

File:Sgubin2017 spg amoc collapse.jpg in this scenario (middle). The collapse of the entire Atlantic Meriditional Overturning Circulation (bottom).]]

{{excerpt|Atlantic meridional overturning circulation|paragraph=1|file=no}}

{{excerpt|Atlantic meridional overturning circulation#Stability and vulnerability|paragraph=1|file=no|hat=no}}

{{excerpt|Atlantic meridional overturning circulation|paragraph=4|file=no|hat=no}}

{{excerpt|Atlantic meridional overturning circulation#Major review studies|paragraphs=2-3|file=no|hat=no}}

{{excerpt|Jet stream#Longer-term climatic changes|paragraphs=1,2,6,7|file=yes}}

{{Main|Territorial claims in the Arctic}}

Growing evidence that global warming is shrinking polar ice has added to the urgency of several nations' Arctic territorial claims in hopes of establishing resource development and new shipping lanes, in addition to protecting sovereign rights.{{cite news | first = Mike | last = Eckel | title = Russia: Tests Show Arctic Ridge Is Ours | url = https://www.washingtonpost.com/wp-dyn/content/article/2007/09/20/AR2007092001703.html |agency=Associated Press | newspaper = The Washington Post | date = 20 September 2007 | access-date = 21 September 2007}}{{dead link|date=June 2021|bot=medic}}{{cbignore|bot=medic}}

As ice sea coverage decreases more and more, year on year, Arctic countries (Russia, Canada, Finland, Iceland, Norway, Sweden, the United States and Denmark representing Greenland) are making moves on the geopolitical stage to ensure access to potential new shipping lanes, oil and gas reserves, leading to overlapping claims across the region.{{Cite web|title=Territorial Claims in the Arctic Circle: An Explainer|url=https://theobserver-qiaa.org/territorial-claims-in-the-arctic-circle-an-explainer|access-date=2021-05-19|website=The Observer|language=en-US}}

There is more activity in terms of maritime boundaries between countries, where overlapping claims for internal waters, territorial seas and particularly Exclusive Economic Zones (EEZs) can cause frictions between nations. Currently, official maritime borders have an unclaimed triangle of international waters lying between them, that is at the centerpoint of international disputes.

This unclaimed land can be obtainable by submitting a claim to the United Nations Convention on the Law of the Sea, these claims can be based on geological evidence that continental shelves extend beyond their current maritime borders and into international waters.

Some overlapping claims are still pending resolution by international bodies, such as a large portion containing the north pole that is both claimed by Denmark and Russia, with some parts of it also contested by Canada. Another example is that of the Northwest Passage, globally recognized as international waters, but technically in Canadian waters. This has led to Canada wanting to limit the number of ships that can go through for environmental reasons but the United States disputes that they have the authority to do so, favouring unlimited passage of vessels.

The Transpolar Sea Route is a future Arctic shipping lane running from the Atlantic Ocean to the Pacific Ocean across the center of the Arctic Ocean. The route is also sometimes called Trans-Arctic Route. In contrast to the Northeast Passage (including the Northern Sea Route) and the North-West Passage it largely avoids the territorial waters of Arctic states and lies in international high seas.{{cite journal|last1=Humpert|first1=Malte|last2=Raspotnik|first2=Andreas|title=The Future of Shipping Along the Transpolar Sea Route|journal=The Arctic Yearbook|year=2012|volume=1|issue=1|pages=281–307|url=http://www.arcticyearbook.com/images/Articles_2012/Humpert_and_Raspotnik.pdf|access-date=18 November 2015|archive-url=https://web.archive.org/web/20160121203700/http://www.arcticyearbook.com/images/Articles_2012/Humpert_and_Raspotnik.pdf|archive-date=21 January 2016|url-status=dead|df=dmy-all}}

Governments and private industry have shown a growing interest in the Arctic.{{cite web|url=http://www.popsci.com/science/article/2013-01/energy-development-arctic|title=As The Earth Warms, The Lure Of The Arctic's Natural Resources Grows|date=18 March 2019}} Major new shipping lanes are opening up: the northern sea route had 34 passages in 2011 while the Northwest Passage had 22 traverses, more than any time in history.{{cite web|url=http://www.aljazeera.com/indepth/opinion/2011/12/2011121913304370977.html|title=Melting Arctic brings new opportunities|first=Michael|last=Byers|website=aljazeera.com}} Shipping companies may benefit from the shortened distance of these northern routes. Access to natural resources will increase, including valuable minerals and offshore oil and gas. Finding and controlling these resources will be difficult with the continually moving ice. Tourism may also increase as less sea ice will improve safety and accessibility to the Arctic.

The melting of Arctic ice caps is likely to increase traffic in and the commercial viability of the Northern Sea Route. One study, for instance, projects, "remarkable shifts in trade flows between Asia and Europe, diversion of trade within Europe, heavy shipping traffic in the Arctic and a substantial drop in Suez traffic. Projected shifts in trade also imply substantial pressure on an already threatened Arctic ecosystem."{{Cite journal|last1=Bekkers|first1=Eddy|last2=Francois|first2=Joseph F.|last3=Rojas-Romagosa|first3=Hugo|date=2016-12-01|title=Melting Ice Caps and the Economic Impact of Opening the Northern Sea Route|journal=The Economic Journal|volume=128|issue=610|language=en|pages=1095–1127|doi=10.1111/ecoj.12460|s2cid=55162828|issn=1468-0297|url=https://boris.unibe.ch/89212/1/Melting%20Ice%20Caps.pdf}}

File:Hjort_2018_permafrost_infrastructure.png

{{excerpt|Permafrost#Infrastructure|paragraphs=1-4|file=no}}

{{excerpt|Permafrost#Release of toxic pollutants}}

{{excerpt|Greenland ice sheet#Geophysical and biochemical role of Greenland's meltwater|paragraph=3|file=no}}

As climate change speeds up, it is having more and more of a direct impact on societies around the world. This is particularly true of people that live in the Arctic, where increases in temperature are occurring at faster rates than at other latitudes in the world, and where traditional ways of living, deeply connected with the natural arctic environment are at particular risk of environmental disruption caused by these changes.{{cite book |last=Hassol |first=Susan Joy |url=https://archive.org/details/impactsofwarming0000hass |title=Impacts of a warming Arctic |publisher=Cambridge University Press |year=2004 |isbn=978-0-521-61778-9 |edition=Reprinted |location=Cambridge, UK |author-link=Susan Joy Hassol |url-access=registration}}

The warming of the atmosphere and ecological changes that come alongside it presents challenges to local communities such as the Inuit. Hunting, which is a major way of survival for some small communities, will be changed with increasing temperatures.{{cite journal |last1=Berkes |first1=Fikret |last2=Jolly |first2=Dyanna |title=Adapting to climate change: social-ecological resilience in a Canadian western Arctic community |url=https://www.ecologyandsociety.org/vol5/iss2/art18/print.pdf |journal=Conservation Ecology |volume=5 |issue=2 |date=2001}} The reduction of sea ice will cause certain species populations to decline or even become extinct. Inuit communities are deeply reliant on seal hunting, which is dependent on sea ice flats, where seals are hunted.{{Cite journal|last=Farquhar|first=Samantha D.|date=2020-03-18|title=Inuit Seal Hunting in Canada: Emerging Narratives in an Old Controversy|url=http://dx.doi.org/10.14430/arctic69833|journal=Arctic|volume=73|issue=1|pages=13–19|doi=10.14430/arctic69833|s2cid=216308832|issn=1923-1245}} In Shishmaref, the seal is a very commonly hunted animal, mainly for preparing seal oil, characterized as “the epicenter of subsistence” because it is a staple ingredient for so many traditions.{{Cite journal |last=Henry-Stone |first=Laura |date=2017-10-07 |title=Elizabeth Marino. Fierce Climate, Sacred Ground: An Ethnography of Climate Change in Shishmaref, Alaska |url=https://doi.org/10.1007/s13412-017-0449-2 |journal=Journal of Environmental Studies and Sciences |volume=7 |issue=4 |pages=569–571 |doi=10.1007/s13412-017-0449-2 |issn=2190-6483}} It is used for cooking so many different meals, preservation practices, and certain ceremonies, and most importantly, it serves as a “symbol of sharing and survival in many Iñupiaq communities”.{{Cite journal |last=Henry-Stone |first=Laura |date=2017-10-07 |title=Elizabeth Marino. Fierce Climate, Sacred Ground: An Ethnography of Climate Change in Shishmaref, Alaska |url=https://doi.org/10.1007/s13412-017-0449-2 |journal=Journal of Environmental Studies and Sciences |volume=7 |issue=4 |pages=569–571 |doi=10.1007/s13412-017-0449-2 |issn=2190-6483}}

The effects of climate change are deeply felt by the Indigenous communities of Alaska, with one of their main struggles being the preservation of traditional subsistence practices that have been passed down by their tribes for centuries.{{Cite journal |last=Henry-Stone |first=Laura |date=2017-10-07 |title=Elizabeth Marino. Fierce Climate, Sacred Ground: An Ethnography of Climate Change in Shishmaref, Alaska |url=https://doi.org/10.1007/s13412-017-0449-2 |journal=Journal of Environmental Studies and Sciences |volume=7 |issue=4 |pages=569–571 |doi=10.1007/s13412-017-0449-2 |issn=2190-6483}} A lot of Indigenous communities in Alaska utilize their land to prepare and store food and to practice old subsistence traditions.{{Cite journal |last=Henry-Stone |first=Laura |date=2017-10-07 |title=Elizabeth Marino. Fierce Climate, Sacred Ground: An Ethnography of Climate Change in Shishmaref, Alaska |url=https://doi.org/10.1007/s13412-017-0449-2 |journal=Journal of Environmental Studies and Sciences |volume=7 |issue=4 |pages=569–571 |doi=10.1007/s13412-017-0449-2 |issn=2190-6483}} In Marino’s book, she explains that on a single fall night in 2013, there was a storm that caused the loss of “thirty to forty feet of land”.{{Cite journal |last=Henry-Stone |first=Laura |date=2017-10-07 |title=Elizabeth Marino. Fierce Climate, Sacred Ground: An Ethnography of Climate Change in Shishmaref, Alaska |url=https://doi.org/10.1007/s13412-017-0449-2 |journal=Journal of Environmental Studies and Sciences |volume=7 |issue=4 |pages=569–571 |doi=10.1007/s13412-017-0449-2 |issn=2190-6483}} Another study proves the same environmental issues occur in other Arctic regions of Alaska, saying the side effects “mediate access to subsistence resources”, ultimately leading to economic problems and severe food insecurity.{{Cite journal |last=Green |first=Kristen |last2=Beaudreau |first2=Anne |last3=Lukin |first3=Maija |last4=Crowder |first4=Larry |date=2021-10-25 |title=Climate change stressors and social-ecological factors mediating access to subsistence resources in Arctic Alaska |url=https://www.ecologyandsociety.org/vol26/iss4/art15/ |journal=Ecology and Society |language=en |volume=26 |issue=4 |doi=10.5751/ES-12783-260415 |issn=1708-3087}}

Unsuspected changes in river and snow conditions will cause herds of animals, including reindeer, to change migration patterns, calving grounds, and forage availability. In good years, some communities are fully employed by the commercial harvest of certain animals. The harvest of different animals fluctuates each year and with the rise of temperatures it is likely to continue changing and creating issues for Inuit hunters, as unpredictability and disruption of ecological cycles further complicate life in these communities, which already face significant problems, such as Inuit communities being the poorest and most unemployed of North America.

Other forms of transportation in the Arctic have seen negative impacts from the current warming, with some transportation routes and pipelines on land being disrupted by the melting of ice. Many Arctic communities rely on frozen roadways to transport supplies and travel from area to area. The changing landscape and unpredictability of weather is creating new challenges in the Arctic.{{Cite journal|last=Timonin|first=Andrey|date=2021|title=Climate Change in the Arctic and Future Directions for Adaptation: Views From Non-Arctic States|url=http://dx.doi.org/10.2139/ssrn.3802303|journal=SSRN Electronic Journal|doi=10.2139/ssrn.3802303|s2cid=233756936|issn=1556-5068}} Researchers have documented historical and current trails created by the Inuit in the Pan Inuit Trails Atlas, finding that the change in sea ice formation and breakup has resulted in changes to the routes of trails created by the Inuit.{{Cite web |last=Rogers |first=Sarah |date=2014-06-13 |title=New online atlas tracks Nunavut's centuries-old Inuit trails |url=https://nunatsiaq.com/stories/article/65674new_online_atlas_tracks_centuries-old_inuit_trails/ |access-date=2021-05-19 |website=Nunatsiaq News |language=en}}

Individual countries within the Arctic zone, Canada, Denmark (Greenland), Finland, Iceland, Norway, Russia, Sweden, and the United States (Alaska) conduct independent research through a variety of organizations and agencies, public and private, such as Russia's Arctic and Antarctic Research Institute. Countries who do not have Arctic claims, but are close neighbors, conduct Arctic research as well, such as the Chinese Arctic and Antarctic Administration (CAA). The United States's National Oceanic and Atmospheric Administration (NOAA) produces an Arctic Report Card annually, containing peer-reviewed information on recent observations of environmental conditions in the Arctic relative to historical records. International cooperative research between nations has also become increasingly important:

• Arctic climate change is summarized by the Intergovernmental Panel on Climate Change (IPCC) in its series of Assessment Reports and the Arctic Climate Impact Assessment.
• European Space Agency (ESA) launched CryoSat-2 on 8 April 2010. It provides satellite data on Arctic ice cover change rates.{{cite web | url = http://www.esa.int/esaLP/ESAOMH1VMOC_LPcryosat_0.html | title = ESA's ice mission CryoSat-2 | date = 11 September 2008 | publisher = esa.int | access-date = 15 June 2009}}
• International Arctic Buoy Program: deploys and maintains buoys that provide real-time position, pressure, temperature, and interpolated ice velocity data
• International Arctic Research Center: Main participants are the United States and Japan.
• International Arctic Science Committee: non-governmental organization (NGO) with diverse membership, including 23 countries from 3 continents.
• 'Role of the Arctic Region', in conjunction with the International Polar Year, was the focus of the second international conference on Global Change Research, held in Nynäshamn, Sweden, October 2007.{{cite web | first = Corinne | last = Wininger | url = http://www.innovations-report.com/html/reports/environment_sciences/report-93680.html | title = E SF, VR, FORMAS sign MOU to promote Global Environmental Change Research | publisher = innovations-report.de | date = 26 October 2007 | access-date = 26 November 2007}}
• SEARCH (Study of Environmental Arctic Change): A research framework originally promoted by several US agencies; an international extension is ISAC (the International Study of Arctic Change{{cite web|url=http://www.arcticchange.org/|title=Arctic Change|website=International Study of Arctic Change}}).

The 2021 Arctic Monitoring and Assessment Programme (AMAP) report by an international team of more than 60 experts, scientists, and indigenous knowledge keepers from Arctic communities, was prepared from 2019 to 2021.{{cite report |title=AMAP Arctic Climate Change Update 2021: Key Trends and Impacts |pages=viii + 148 |work=Arctic Monitoring and Assessment Programme (AMAP) |date=2021 |location= Tromsø, Norway |isbn=978-82-7971-201-5 }}{{rp|vii}} It is a follow-up report of the 2017 assessment, "Snow, Water, Ice and Permafrost in the Arctic" (SWIPA).{{rp|vii}} The 2021 IPCC AR6 WG1 Technical Report confirmed that "[o]bserved and projected warming" were ""strongest in the Arctic".{{Cite book |chapter= Technical Summary |last1=Arias |first1=Paola A. |last2 = Bellouin |first2= Nicolas |last3 = Coppola |first3 = Erika |last4 = Jones |first4 = Richard G. |last5 = Krinner |first5 = Gerhard |display-authors=4 |chapter-url= https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_TS.pdf |year= 2021 |title= IPCC AR6 WG1 |pages=76 }}{{rp|29}} According to an 11 August 2022 article published in Nature, there have been numerous reports that the Arctic is warming from twice to three times as fast as the global average since 1979, but the co-authors cautioned that the recent report of the "four-fold Arctic warming ratio" was potentially an "extremely unlikely event".{{Cite journal |last1=Rantanen |first1=Mika |last2=Karpechko |first2=Alexey Yu |last3=Lipponen |first3=Antti |last4=Nordling |first4=Kalle |last5=Hyvärinen |first5=Otto |last6=Ruosteenoja |first6=Kimmo |last7=Vihma |first7=Timo |last8=Laaksonen |first8=Ari |date=11 August 2022 |title=The Arctic has warmed nearly four times faster than the globe since 1979 |url=https://www.nature.com/articles/s43247-022-00498-3 |journal=Communications Earth & Environment |language=en |volume=3 |issue=1 |page=168 |doi=10.1038/s43247-022-00498-3 |bibcode=2022ComEE...3..168R |s2cid=251498876 |issn=2662-4435}} The annual mean Arctic Amplification (AA) index had "reached values exceeding four" from c. 2002 through 2022, according to a July 2022 article in Geophysical Research Letters.{{cite journal |last1=Chylek |first1=Petr |last2=Folland |first2=Chris |last3=Klett |first3=James D. |last4=Wang |first4=Muyin |last5=Hengartner |first5=Nick |last6=Lesins |first6=Glen |last7=Dubey |first7=Manvendra K. |title=Annual Mean Arctic Amplification 1970–2020: Observed and Simulated by CMIP6 Climate Models |journal=Geophysical Research Letters |date=16 July 2022 |volume=49 |issue=13 |doi=10.1029/2022GL099371 |bibcode=2022GeoRL..4999371C |s2cid=250097858 |language=en |issn=0094-8276 }} via Wikipedia Library and EBSCOhost{{rp|1}}{{cite news |title=Arctic temperatures are increasing four times faster than global warming |url=https://phys.org/news/2022-07-arctic-temperatures-faster-global.html |access-date=18 July 2022 |work=Los Alamos National Laboratory |language=en}}

The 14 December 2021 16th Arctic Report Card produced by the United States's National Oceanic and Atmospheric Administration (NOAA) and released annually, examined the "interconnected physical, ecological and human components" of the circumpolar Arctic.{{cite report |url=http://www.arctic.noaa.gov/Report-Card/Report-Card-2021 |series=Arctic Report Card: Update for 2021 |title=Rapid and pronounced warming continues to drive the evolution of the Arctic environment |publisher=NOAA}}{{cite news |last1=Druckenmiller |first1=Matthew |last2=Thoman |first2=Rick |last3=Moon |first3=Twila |author-link3=Twila Moon |title=2021 Arctic Report Card reveals a (human) story of cascading disruptions, extreme events and global connections |url=https://theconversation.com/2021-arctic-report-card-reveals-a-human-story-of-cascading-disruptions-extreme-events-and-global-connections-172136 |access-date=30 January 2022 |agency=The Conversation |date=14 December 2021}} The report said that the 12 months between October 2020 and September 2021 were the "seventh warmest over Arctic land since the record began in 1900". The 2017 report said that the melting ice in the warming Arctic was unprecedented in the past 1500 years.{{cite web |url=https://mashable.com/2017/12/12/arctic-ice-melt-warming-unprecedented-1500-years-report-card |title=Arctic warming, ice melt 'unprecedented' in at least the past 1,500 years |first=Andrew |last=Freedman |date=12 December 2017 |work=Mashable |access-date=13 December 2017}}{{cite web |url=https://www.arctic.noaa.gov/Report-Card/Report-Card-2017 |title=Arctic Report Card: Update for 2017; Arctic shows no sign of returning to reliably frozen region of recent past decades |work=NOAA |access-date=13 December 2017}} NOAA's State of the Arctic Reports, starting in 2006, updates some of the records of the original 2004 and 2005 Arctic Climate Impact Assessment (ACIA) reports by the intergovernmental Arctic Council and the non-governmental International Arctic Science Committee.{{cite report |work=Arctic Climate Impact Assessment (ACIA) |date=15 October 2004 |title=Impacts of a Warming Arctic: Arctic Climate Impact Assessment |isbn=0-521-61778-2 |series= Overview report |publisher=Cambridge University Press |pages=140}}

A 2022 United Nations Environment Programme (UNEP) report "Spreading Like Wildfire: The Rising Threat Of Extraordinary Landscape Fires" said that smoke from wildfires around the world created a positive feedback loop that is a contributing factor to Arctic melting.{{cite report |work=United Nations Environment Programme (UNEP) |date=2022 |title=Spreading like Wildfire – The Rising Threat of Extraordinary Landscape Fires |series=A UNEP Rapid Response Assessment |location=Nairobi, Kenya |pages=122}}{{cite news |last1=McGrath |first1=Matt |title=Climate change: Wildfire smoke linked to Arctic melting |url=https://www.bbc.com/news/science-environment-60782084 |access-date=20 March 2022 |agency=BBC |date=19 March 2022}} The 2020 Siberian heatwave was "associated with extensive burning in the Arctic Circle".{{rp|36}} Report authors said that this extreme heat event was the first to demonstrate that it would have been "almost impossible" without anthropogenic emissions and climate change.{{cite journal |last1=Ciavarella |first1=A. |last2=Cotterill |first2=D. |last3=Stott |first3=P. |title=Prolonged Siberian heat of 2020 almost impossible without human influence |journal=Climatic Change |volume=166 |number=9 |date=2021 |page=9 |doi=10.1007/s10584-021-03052-w|pmid=34720262 |pmc=8550097 |bibcode=2021ClCh..166....9C |s2cid=233875870 }}{{rp|36}}

{{portal|Climate change|Ecology|Environment}}

{{div col}}

• Arctic cooperation and politics
• Arctic haze
• Arctic sea ice ecology and history
• Atlantification of the Arctic
• Atmospheric Brown Cloud
• Climate of the Arctic
• Climate and vegetation interactions in the Arctic
• Northern Sea Route
• Climate change in Antarctica
• Ozone depletion and climate change
• Save the Arctic

{{div col end}}

{{reflist|30em}}

• {{Cite book |ref= {{harvid|IPCC AR6 WG1|2021}}

|author= IPCC |author-link= IPCC

|year= 2021

|title= Climate Change 2021: The Physical Science Basis

|series= Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change

|display-editors= 4

|editor1-first= V. |editor1-last= Masson-Delmotte

|editor2-first= P. |editor2-last= Zhai

|editor3-first= A. |editor3-last= Pirani

|editor4-first= S. L. |editor4-last= Connors

|editor5-first= C. |editor5-last= Péan

|editor6-first= S. |editor6-last= Berger

|editor7-first= N. |editor7-last= Caud

|editor8-first= Y. |editor8-last= Chen

|editor9-first= L. |editor9-last= Goldfarb

|editor10-first= M. I. |editor10-last= Gomis

|publisher= Cambridge University Press (In Press)

|place=

|isbn=

|url= https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Full_Report.pdf

}}

• {{Cite book

|ref= {{harvid|IPCC AR6 WG1 Ch9|2021}}

|chapter=Chapter 9: Ocean, cryosphere, and sea level change

| last1 = Fox-Kemper| first1 = Baylor| last2 = Hewitt| first2 = Helene T.| last3 = Xiao| first3 = Cunde| last4 = Aðalgeirsdóttir| first4 = Guðfinna| last5 = Drijfhout| first5 = Sybren S.| last6 = Edwards| first6 = Tamsin L.| last7 = Golledge| first7 = Nicholas R.

|chapter-url= https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter_09.pdf

|display-authors=4

|title= {{Harvnb|IPCC AR6 WG1|2021}}

|year=2021

}}

• {{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.]

• {{cite web | title=Black Carbon and Methane | website=Arctic Council | date=9 Jul 2018 | url=https://arctic-council.org/about/task-expert/egbcm/ | access-date=6 Nov 2023}}
• {{cite web | last=Hersher | first=Rebecca | title=The Arctic is heating up nearly four times faster than the whole planet, study finds | website=NPR | date=11 Aug 2022 | url=https://www.npr.org/2022/08/11/1116608415/the-arctic-is-heating-up-nearly-four-times-faster-than-the-rest-of-earth-study-f | access-date=6 Nov 2023}}

• [http://www.arctic.noaa.gov/ Arctic Change website, in near-realtime]
• [http://nsidc.org/arcticseaicenews/ Arctic Sea Ice News & Analysis]
• {{Cite news |last=Smith |first=Duane |date=2007 |title=Climate Change In The Arctic: An Inuit Reality |work=UN Chronicle |url=https://www.un.org/en/chronicle/article/climate-change-arctic-inuit-reality}}
• [http://www.arctic.io/#home The Arctic ice sheet], satellite map with daily updates.
• NOAA: [http://www.arctic.noaa.gov Arctic Theme Page] – A comprehensive resource focused on the Arctic
• {{cite report |url=http://www.arctic.noaa.gov/Report-Card/Report-Card-2016 |series=Arctic Report Card: Update for 2016 |title=Persistent warming trend and loss of sea ice are triggering extensive Arctic changes |publisher=NOAA}}
• {{cite report |url=http://www.arctic.noaa.gov/Report-Card/Report-Card-2021 |series=Arctic Report Card: Update for 2021 |title=Rapid and pronounced warming continues to drive the evolution of the Arctic environment |publisher=NOAA}}
• [https://origins.osu.edu/article/pollution-climate-change-killing-arctic?language_content_entity=en Killing the Arctic] Origins: Current Events in Historical Perspective (October 2020), by John McCannon

{{Arctic topics}}

{{Climate change regions|state=expanded}}

G

Category:Arctic research

Category:Effects of climate change

Category:Environment of the Arctic

Arctic Sea, Global warming

Arctic Sea, Global warming

Category:Regional effects of climate change

Arctic