Climate change in the Arctic

Climate change in the Arctic
Very substantial decrease in Arctic Sea ice in 2007 from 2005 and also from 1979–2000 average
Greenland Ice Sheet Mass Trend

Ongoing changes in the climate of the Arctic include rising temperatures, loss of sea ice, and melting of the Greenland ice sheet. Projections of sea ice loss suggest that the Arctic ocean will likely be free of summer sea ice sometime between 2060 and 2080,[1] while another estimate puts this date at 2030.[2] Because of the amplified response of the Arctic to global warming, it is often seen as a high-sensitivity indicator of climate change. Scientists also point to the potential for release of methane from the Arctic region, especially through the thawing of permafrost and methane clathrates. Arctic climate changes are summarized in the IPCC Fourth Assessment Report and the Arctic Climate Impact Assessment.

The National Oceanic and Atmospheric Administration (NOAA)'s Arctic Report Card presents annually updated, peer-reviewed information on recent observations of environmental conditions in the Arctic relative to historical records.

Contents

Modelling, history, and predictions of sea ice

See also: Arctic sea ice ecology and history
Seasonal variation and long term decrease of arctic sea ice extent as determined by satellite measurements.[3]
Seasonal variation and long term decrease of Arctic sea ice volume as determined by measurement backed numerical modelling.[4]

Computer models predict that the sea ice area will continue to shrink in the future, although recent work has called into question their ability to accurately predict sea ice changes.[5] Current climate models frequently underestimate the rate of sea ice retreat.[6] In 2007 the IPCC reported that “the projected reduction [in global sea ice cover] is accelerated in the Arctic, where some models project summer sea ice cover to disappear entirely in the high-emission A2 scenario in the latter part of the 21st century.″ [7] There is currently no scientific evidence that a seasonally ice-free Arctic Ocean existed anytime in the last 700,000 years, although there were periods when the Arctic was warmer than it is today.[8][9] Scientists are studying possible causal factors such as direct changes resulting from the greenhouse effect as well as indirect changes such as unusual wind patterns,[10] rising Arctic temperatures,[11] or shifting water circulation[12] (such as increasing inflows of warm, fresh water to the Arctic Ocean from rivers.)

According to the Intergovernmental Panel on Climate Change, "warming in the Arctic, as indicated by daily maximum and minimum temperatures, has been as great as in any other part of the world."[13] Reduction of the area of Arctic sea ice means less solar energy is reflected back into space, thus accelerating the reduction.[14] Studies have shown that recent warming in the polar regions was due to the net effect human influence; the warming radiative forcing of greenhouse gases is only partially offset by the cooling effect of ozone depletion.[15]

1870–2009 Northern hemisphere sea ice extent in million square kilometers. Blue shading indicates the pre-satellite era; data then is less reliable. In particular, the near-constant level extent in Autumn up to 1940 reflects lack of data rather than a real lack of variation.

Reliable measurement of sea ice edge begin within the satellite era in the late 1970s. Before this the region was less well monitored by a combination of ships, buoys and aircraft.[16] On top of the long-term negative trend in recent years, attributed to global warming, there is considerable interannual variation.[17] Some of this variation may be related to effects such as the arctic oscillation, which may itself be related to global warming;[18] some of the variation is essentially random "weather noise".

The Arctic sea ice September minimum extent reached new record lows in 2002, 2005, and 2007 (39.2 percent below the 1979–2000 average). In 2007, Arctic sea ice broke all previous records by early August—a month before the end of melt season, with the biggest decline ever in Arctic sea ice minimum extent, more than a million square kilometers.[19] In the first time in human memory, the fabled Northwest Passage opened completely.[20] The dramatic 2007 melting surprised and concerned scientists.[21][22]

In 2008 and 2009, Arctic sea ice minimum extent was higher than 2007, but it did not return to the levels of previous years.[23]

The sea ice thickness field, and accordingly the ice volume and mass, is much more difficult to determine than the extension. Exact measurements can be made only at a limited number of points. Because of large variations in ice and snow thickness and consistency air- and spaceborne measurements have to be evaluated carefully. Nevertheless the studies made support the assumption of a dramatic decline in ice age and – thickness.[23] The Catlin Arctic Survey reported an average thickness of 1.8 meters across the northern Beaufort Sea, an area that had traditionally contained older, thicker ice.[24]. Another approach[4] is to simulate ice growth, melting and drift numerically in an integrated ocean-atmosphere model with input parameters fine tuned to fit model output to known thickness and extent data. The resulting time development shows a decrease of ice mass that is striking even after consideration of a possibly somewhat larger error bar than that of the extension data. Near complete ice freeness of the arctic ocean in late summer is probable as early as 2018.

The rate of the decline in entire arctic ice coverage is accelerating. From 1979–1996, the average per decade decline in entire ice coverage was a 2.2% decline in ice extent (i.e., area with at least 15% sea ice coverage) and a 3% decline in ice area. For the decade ending 2008, these values have risen to 10.1% and 10.7%, respectively. These are comparable to the September to September loss rates in year-round ice (i.e., perennial ice, which survives throughout the year), which averaged a retreat of 10.2% and 11.4% per decade, respectively, for the period 1979–2007.[25] This is consistent with ICESat measurements indicating decreased thickness in arctic ice and a decline in multi-year ice. For the period 2005–2008, multi-year ice decreased 42% in coverage and 40% in volume, a loss of ~6300 km3.[26]

A 2010 study attributes that the recent Arctic temperature amplification was caused by the loss of sea ice itself, which exposes water instead of more reflective ice to solar radiation.[27]

Effects

Earlier retreat of sea ice in Barrow, Alaska

The effects of Arctic climate change include a marked decrease in Arctic sea ice; melting permafrost, leading to the release of methane, a potent greenhouse gas;[28] the release of methane from clathrates, leading to longer time-scale methane release;[29] the observed increase in melt on the Greenland Ice Sheet in recent years; and potential changes in patterns of ocean circulation. Scientists worry that some of these effects may cause positive feedbacks which could accelerate the rate of global warming.

Sea ice

The number of days where the arctic is in the melt stage has increased since satellite records began in 1979. Red indicates more melting, blue less melting.

The sea ice in the Arctic region is in itself important in maintaining global climate due to its albedo (reflectivity).[30] Melting of this sea ice will therefore exacerbate global warming due to positive feedback effects, where warming creates more warming by increased solar absorption.[30][31] An important feedback in the Arctic currently is ice-albedo feedback. The loss of the Arctic sea ice may represent a tipping point in global warming, when 'runaway' climate change starts.[32][33] This would be due to the release of methane from permafrost and clathrates in the region, and also because of ice-albedo feedback effects. However, recent research has challenged the notion of ice-albedo feedback causing an imminent Arctic sea ice tipping point.[34][35]

Projected change in polar bear habitat from 2001–2010 to 2041–2050

April 3, 2007, the National Wildlife Federation urged the United States Congress to place polar bears under the Endangered Species Act.[36] Four months later, the United States Geological Survey completed a year-long study[37] which concluded in part that the floating Arctic sea ice will continue its rapid shrinkage over the next 50 years, consequently wiping out much of the polar bear habitat. The bears would disappear from Alaska, but would continue to exist in the Canadian Arctic Archipelago and areas off the northern Greenland coast.[38] Secondary ecological effects are also resultant from the shrinkage of sea ice; for example, Polar Bears are denied their historic length of seal hunting season due to late formation and early thaw of pack ice.

Loss of permafrost

Main article: Arctic methane release

Sea ice loss has melting effects on permafrost,[39] both in the sea,[40] and on land[41] and consequential effects on methane release, and wildlife.[41] Some studies imply a direct link, as they predict cold air passing over ice is replaced by warm air passing over the sea. This warm air carries heat to the permafrost around the Arctic, and melts it.[41] This thawing of the permafrost might accelerate methane release from areas like Siberia.[42]

Clathrate gun

Main article: Clathrate gun hypothesis

Sea ice serves to stabilise methane deposits on and near the shoreline,[43] preventing the clathrate breaking down and outgassing methane into the atmosphere. Any methane released to the atmosphere will then cause further warming.

Melting of the Greenland Ice Sheet

Models predict a sea-level contribution of about 5 centimetres (2 in) from melting in Greenland during the 21st century.[44] It is also predicted that Greenland will become warm enough by 2100 to begin an almost complete melt during the next 1,000 years or more.[45][46]

Ice thickness measurements from the GRACE satellite indicate that ice mass loss is accelerating. For the period 2002–2009, the rate of loss increased from −137 Gt/yr to −286 Gt/yr, with an acceleration of −30 gigatonnes per year per year.[47]

Effect on ocean circulation

See also: Shutdown of thermohaline circulation and Ocean anoxic event

Although this is now thought unlikely in the near future, it has also been suggested that there could be a shutdown of thermohaline circulation, similar to that which is believed to have driven the Younger Dryas, an abrupt climate change event. There is also potentially a possibility of a more general disruption of ocean circulation, which may lead to an ocean anoxic event, although these are believed to be much more common in the distant past. It is unclear whether the appropriate pre-conditions for such an event exist today.

Control of Arctic climate change

Geoengineering

See also: Arctic geoengineering and Geoengineering

Geoengineering approaches offer interventions which may increase Arctic ice, or reduce its decline.[48] These operate either by regional effects (Arctic geoengineering) or global effects (geoengineering). Several specific Arctic geoengineering schemes have been proposed to reduce Arctic climate change. Further, scientists such as Paul Crutzen have argued for general geoengineering proposals such as using stratospheric sulfur aerosols to be used, which will affect the Arctic if deployed in or near this region.

According to John Holdren, Assistant to the President of the United States for Science and Technology, complete loss of summer sea ice in the Arctic would be a milestone that could justify geoengineering in order to purposely cool the climate. Holdren believes that complete loss of summer sea ice in the Arctic could signal an increased chance of "really intolerable consequences."[49]

Research

National

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).

International

International cooperative research between nations has become increasingly important:

Territorial claims

Main article: 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.[53]

Danish Foreign Minister Per Stig Møller and Greenland's Premier Hans Enoksen invited foreign ministers from Canada, Norway, Russia and the United States to Ilulissat, Greenland for a summit in May 2008 to discuss how to divide borders in the changing Arctic region, and a discussion on more cooperation against climate change affecting the Arctic.[54] At the Arctic Ocean Conference, Foreign Ministers and other officials representing the five countries announced the Ilulissat Declaration on May 28, 2008.[55][56]

See also

References

  1. ^ Bo, J.; Hall, A.; Qu, X. (2009). "September sea-ice cover in the Arctic Ocean projected to vanish by 2100". Nature Geoscience 2 (5): 341. Bibcode 2009NatGe...2..341B. doi:10.1038/ngeo467.  edit
  2. ^ Roach, John (2009-10-15). "Arctic Largely Ice Free in Summer Within Ten Years?". National Geographic News. http://news.nationalgeographic.com/news/2009/10/091015-arctic-ice-free-gone-global-warming.html. Retrieved 2010-10-02. 
  3. ^ Fetterer, F., K. Knowles, W. Meier, and M. Savoie. 2002, updated 2009. Sea Ice Index. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.
  4. ^ a b Zhang, Jinlun and D.A. Rothrock: Modeling global sea ice with a thickness and enthalpy distribution model in generalized curvilinear coordinates, Mon. Wea. Rev. 131(5), 681–697, 2003. [1]
  5. ^ Eisenman, Ian; Untersteiner, Norbert; Wettlaufer, J.S. (2007). "On the reliability of simulated Arctic sea ice in Global Climate Models". Geophysical Research Letters 34 (10): L10501. Bibcode 2007GeoRL..3410501E. doi:10.1029/2007GL029914. http://pantheon.yale.edu/%7Ejw378/articles/EUW_revised_2007.pdf.  This is due to high sea ice thickness sensitivity to variations in downward thermal radiation, which are not reflected in outcomes of different models but seem to have been compensated by adaption of other parameters like albedo, short wave irradiation or ocean heat flux.
  6. ^ Stroeve, J.; Holland, M. M.; Meier, W.; Scambos, T.; Serreze, M. (2007). "Arctic sea ice decline: Faster than forecast". Geophysical Research Letters 34 (9): L09501. Bibcode 2007GeoRL..3409501S. doi:10.1029/2007GL029703.  edit
  7. ^ Meehl, G.A., and others; Intergovernmental Panel on Climate Change Working Group I. (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Chapter 10. New York: Cambridge University Press. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter10.pdf. 
  8. ^ Overpeck, Jonathan T.; Sturm, Matthew; Francis, Jennifer A.; Perovich, Donald K.; Serreze, Mark C.; Benner, Ronald; Carmack, Eddy C.; Chapin, F. Stuart et al. (2005-08-23). "Arctic System on Trajectory to New, Seasonally Ice-Free State" (PDF). Eos, Transactions, American Geophysical Union 86 (34): 309–316. doi:10.1029/2005EO340001. http://atoc.colorado.edu/~dcn/reprints/Overpeck_etal_EOS2005.pdf. Retrieved 2007-12-24. 
  9. ^ Butt, F. A.; H. Drange, A. Elverhoi, O. H. Ottera & A. Solheim (2002). The Sensitivity of the North Atlantic Arctic Climate System to Isostatic Elevation Changes, Freshwater and Solar Forcings. 21. Quaternary Science Reviews. pp. 1643–1660. OCLC 108566094. http://www.nersc.no/~oddho/Thesis/chapter3.pdf. 
  10. ^ "Winds from Siberia reduce Arctic sea ice cover". The Research Council of Norway. 2010-04-27. http://www.forskningsradet.no/en/Newsarticle/Winds_from_Siberia_reduce_Arctic_sea_ice_cover/1253955174381. Retrieved 2010-04-27. 
  11. ^ Black, Richard (2006-09-14). "'Drastic' shrinkage in Arctic ice". Science/Nature (BBC News). http://news.bbc.co.uk/2/hi/science/nature/5344208.stm. Retrieved 2007-09-16. 
  12. ^ "Study: Circulation Shift May Be Melting Arctic Sea Ice". Fox News. 2007-11-24. http://www.foxnews.com/story/0,2933,311753,00.html. Retrieved 2007-11-27. 
  13. ^ McCarthy, James J.; Intergovernmental Panel on Climate Change Working Group II. (2001). Climate Change 2001: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Third Assessment Report of the Intergovernmental Panel on Climate Change. New York: Cambridge University Press. ISBN 0521807689. http://www.grida.no/climate/ipcc_tar/wg2/597.htm#16131. Retrieved 2007-12-24. 
  14. ^ Black, Richard (2007-05-18). "Earth – melting in the heat?". BBC News. http://news.bbc.co.uk/2/hi/science/nature/4315968.stm. Retrieved 2008-01-03. 
  15. ^ Gillett, N. P.; Stone, D. I. A.; Stott, P. A.; Nozawa, T.; Karpechko, A. Y.; Hegerl, G. C.; Wehner, M. F.; Jones, P. D. (2008). "Attribution of polar warming to human influence". Nature Geoscience 1 (11): 750. doi:10.1038/ngeo338.  edit
  16. ^ Meier, W.N.; J.C. Stroeve, and F. Fetterer (2007). "Whither Arctic sea ice? A clear signal of decline regionally, seasonally and extending beyond the satellite record". Annals of Glaciology 46: 428–434. Bibcode 2007AnGla..46..428M. doi:10.3189/172756407782871170. http://www.igsoc.org/annals/46/a46a251.pdf. 
  17. ^ "NASA Sees Arctic Ocean Circulation Do an About-Face". JPL News (Pasadena: JPL/California Institute of Technology). 2007-11-13. http://www.jpl.nasa.gov/news/news.cfm?release=2007-131. Retrieved 2010-07-26. 
  18. ^ Fyfe, J.C; G.J. Boer and G.M. Flato (1999-06-01). "The Arctic and Antarctic Oscillations and their Projected Changes Under Global Warming". Geophysical Research Letters 26 (11): 1601–4. Bibcode 1999GeoRL..26.1601F. doi:10.1029/1999GL900317. 
  19. ^ "State of the Cryosphere, Is the Cryosphere sending signals about climate change?". National Snow and Ice Data Center. 2010-02-18. http://nsidc.org/sotc/sea_ice.html. Retrieved 2010-07-26. 
  20. ^ NSIDC 1 October 2007 "Arctic Sea Ice Shatters All Previous Record Lows – Diminished summer sea ice leads to opening of the fabled Northwest Passage"
  21. ^ Cole, Stephen (2007-09-25). "'Remarkable' Drop in Arctic Sea Ice Raises Questions". NASA. http://www.nasa.gov/vision/earth/environment/arctic_minimum.html. Retrieved 2010-07-26. 
  22. ^ "Monitoring Sea Ice". NASA Earth Observatory. NASA. 2010-07-25. http://earthobservatory.nasa.gov/Features/SeaIce/page2.php. Retrieved 2010-07-26. 
  23. ^ a b "Arctic sea ice extent remains low; 2009 sees third-lowest mark". NSIDC. 2009-10-06. http://nsidc.org/news/press/20091005_minimumpr.html. Retrieved 2010-07-26. 
  24. ^ Catlin Arctic Survey "SURVEY DATA SUPPORTS RAPID ICE LOSS – LARGELY OPEN ARCTIC SEAS IN SUMMER WITHIN TEN YEARS"
  25. ^ Josefino C. Comiso, Claire L. Parkinson, Robert Gersten, and Larry Stock (2008), "Accelerated decline in Arctic sea ice cover" Geophysical Research Letters 35 L01703 doi:10.1029/2007GL031972
  26. ^ R. Kwok, G. F. Cunningham, M. Wensnahan, I. Rigor, H. J. Zwally, and D. Yi (2009), "Thinning and volume loss of Arctic sea ice: 2003–2008" Journal of Geophysical Research 114 C07005 doi:10.1029/2009JC005312
  27. ^ Screen, J. A.; Simmonds, I. (2010). "The central role of diminishing sea ice in recent Arctic temperature amplification". Nature 464 (7293): 1334–1337. Bibcode 2010Natur.464.1334S. doi:10.1038/nature09051. PMID 20428168.  edit
  28. ^ Christensen, T. R.; Johansson, T. Ö.; Jonas Åkerman, H.; Mastepanov, M.; Malmer, N.; Friborg, T.; Crill, P.; Svensson, B. H. (2004). "Thawing sub-arctic permafrost: Effects on vegetation and methane emissions". Geophysical Research Letters 31 (4): L04501. Bibcode 2004GeoRL..3104501C. doi:10.1029/2003GL018680.  edit
  29. ^ Macdonald, G. J. (1990). "Role of methane clathrates in past and future climates". Climatic Change 16 (3): 247–243. doi:10.1007/BF00144504.  edit
  30. ^ a b "All About Sea Ice". NSIDC. http://www.nsidc.org/seaice/intro.html. Retrieved 2009-01-10. 
  31. ^ "Global Outlook for Ice and Snow, Chapter 5: Ice in the Sea". United Nations Environment Programme. pp. 75–76. http://www.unep.org/geo/geo_ice/PDF/GEO_C5_LowRes.pdf. 
  32. ^ Lawrence, D. M.; Slater, A. (2005). "A projection of severe near-surface permafrost degradation during the 21st century". Geophysical Research Letters 32 (24): L24401. Bibcode 2005GeoRL..3224401L. doi:10.1029/2005GL025080.  edit
  33. ^ Archer, D.; Bufett, B. (2005). "Time-dependent response of the global ocean clathrate reservoir to climatic and anthropogenic forcing". Geochemistry Geophysics Geosystems 6 (3): Q03002. Bibcode 2005GGG.....603002A. doi:10.1029/2004GC000854. http://geosci.uchicago.edu/~archer/reprints/archer.2005.clathrates.pdf.  edit
  34. ^ "Arctic summer sea ice loss may not 'tip' over the edge". environmentalresearchweb. 2009-01-30. http://environmentalresearchweb.org/cws/article/research/37591. Retrieved 2010-07-26. 
  35. ^ Eisenman, Ian; Wettlaufer, J.S. (2009). "Nonlinear threshold behavior during the loss of Arctic sea ice". Proceedings of the National Academy of Sciences of the United States of America 106 (1): 28–32. Bibcode 2009PNAS..106...28E. doi:10.1073/pnas.0806887106. PMC 2629232. PMID 19109440. http://pantheon.yale.edu/%7Ejw378/articles/E&W_Bif_PNAS.pdf. 
  36. ^ "Protection For Polar Bears Urged By National Wildlife Federation". Science Daily. 2008-04-03. http://www.sciencedaily.com/releases/2008/04/080402210456.htm. Retrieved 2008-04-03. 
  37. ^ DeWeaver, Eric; U.S. Geological Survey (2007). "Uncertainty in Climate Model Projections of Arctic Sea Ice Decline: An Evaluation Relevant to Polar Bears" (PDF). United States Department of the Interior. OCLC 183412441. http://www.usgs.gov/newsroom/special/polar_bears/docs/USGS_PolarBear_DeWeaver_GCM-Uncertainty.pdf. 
  38. ^ Broder, John; Revkin, Andrew C. (2007-07-08). "Warming Is Seen as Wiping Out Most Polar Bears". The New York Times. http://www.nytimes.com/2007/09/08/science/earth/08polar.html?_r=1&hp=&adxnnl=1&oref=slogin&adxnnlx=1190574637-aS0VOr2klykTSNwK91tiDg. Retrieved 2007-09-23. 
  39. ^ "Microsoft Word - lawrence.grl.submit.doc" (PDF). http://www.cgd.ucar.edu/ccr/dlawren/publications/lawrence.grl.submit.2008.pdf. Retrieved 2010-07-26. 
  40. ^ Stranahan, Susan Q.. "Melting Arctic Ocean Raises Threat of ‘Methane Time Bomb’". E360.yale.edu. http://e360.yale.edu/content/feature.msp?id=2081. Retrieved 2010-07-26. 
  41. ^ a b c "Permafrost Threatened by Rapid Retreat of Arctic Sea Ice, NCAR Study Finds – News Release". Ucar.edu. http://www.ucar.edu/news/releases/2008/permafrost.jsp. Retrieved 2010-07-26. 
  42. ^ "Methane Bubbling Up From Undersea Permafrost?". News.nationalgeographic.com. http://news.nationalgeographic.com/news/2008/12/081219-methane-siberia.html. Retrieved 2010-07-26. 
  43. ^ Shakhova, N.; Semiletov, I.; Panteleev, G. (2005). "The distribution of methane on the Siberian Arctic shelves: Implications for the marine methane cycle". Geophysical Research Letters 32 (9): L09601. Bibcode 2005GeoRL..3209601S. doi:10.1029/2005GL022751.  edit
  44. ^ IPCC AR4 chapter 10 [2] Table 10.7
  45. ^ Gregory JM; Huybrechts P; Raper SC (April 2004). "Climatology: threatened loss of the Greenland ice-sheet". Nature 428 (6983): 616. Bibcode 2004Natur.428..616G. doi:10.1038/428616a. PMID 15071587. http://homepages.vub.ac.be/~phuybrec/pdf/Nature.Green.2004.pdf. "The Greenland ice-sheet would melt faster in a warmer climate and is likely to be eliminated — except for residual glaciers in the mountains — if the annual average temperature in Greenland increases by more than about 3 °C. This would raise the global average sea-level by 7 metres over a period of 1000 years or more. We show here that concentrations of greenhouse gasses will probably have reached levels before the year 2100 that are sufficient to raise the temperature past this warming threshold." 
  46. ^ "Regional Sea Level Change" (Figure 11.16). Intergovernmental Panel on Climate Change. http://www.grida.no/climate/ipcc_tar/wg1/432.htm#fig1116. 
  47. ^ Velicogna, I. (2009), Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE, Geophysical Research Letters, 36, L19503, doi:10.1029/2009GL040222
  48. ^ Lenton, T; N. Vaughan. "Geoengineering: a critical review". http://www.cosis.net/abstracts/EGU2008/09934/EGU2008-A-09934.pdf?PHPSESSID=. Retrieved 2009-02-23. 
  49. ^ Borenstein, Seth. “Obama Looking at Cooling Air to Fight Warming”, Associated Press via ABC News. (2009-04-09).
  50. ^ "ESA's ice mission CryoSat-2". esa.int. 2008-09-11. http://www.esa.int/esaLP/ESAOMH1VMOC_LPcryosat_0.html. Retrieved 2009-06-15. 
  51. ^ Svenningsson, Annakarin (2007-10-14). "Global Environmental Change – The Role of the Arctic Region". innovations-report.de. http://www.innovations-report.de/html/berichte/veranstaltungen/bericht-92741.html. Retrieved 2007-10-16. 
  52. ^ Wininger, Corinne (2007-10-26). "E SF, VR, FORMAS sign MOU to promote Global Environmental Change Research". innovations-report.de. http://www.innovations-report.com/html/reports/environment_sciences/report-93680.html. Retrieved 2007-11-26. 
  53. ^ Eckel, Mike (2007-09-20). "Russia: Tests Show Arctic Ridge Is Ours". Associated Press. The Washington Post. http://www.washingtonpost.com/wp-dyn/content/article/2007/09/20/AR2007092001703.html. Retrieved 2007-09-21. [dead link]
  54. ^ "Denmark aims for meeting of Arctic nations to discuss borders" (online). Denmark-Diplomacy (EUX.TV the Europe channel). 2007-09-13. Archived from the original on 2008-02-29. http://web.archive.org/web/20080229021337/http://www.eux.tv/article.aspx?articleId=14443. Retrieved 2007-09-16. 
  55. ^ "Conference in Ilulissat, Greenland: Landmark political declaration on the future of the Arctic". Ministry of Foreign Affairs of Denmark. 2008-05-28. Archived from the original on 2008-06-15. http://web.archive.org/web/20080615022625/http://www.um.dk/en/servicemenu/News/ConferenceInIlulissatGreenlandLandmarkPoliticalDeclarationOnTheFutureOfTheArctic.htm. Retrieved 2008-06-06. 
  56. ^ "The Ilulissat Declaration". um.dk. 2008-05-28. http://www.um.dk/NR/rdonlyres/BE00B850-D278-4489-A6BE-6AE230415546/0/ArcticOceanConference.pdf. Retrieved 2008-06-06. 

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