Climate change in the Arctic

The effects of global warming in the Arctic, or climate change in the Arctic include rising air and water temperatures, loss of sea ice, and melting of the Greenland ice sheet with a related cold temperature anomaly, observed in recent years. Other concerns include circulation changes, increased input of freshwater, ocean acidification, sea level rise, and indirectly through potential climate teleconnections to mid latitudes and the greater frequency of extreme weather events (flooding, fires and drought), ecological, biological and phenology changes, biological migrations and extinctions, natural resource stresses and as well as human health, displacement and security issues. Also potential methane releases from the region, especially through the thawing of permafrost and methane clathrates, is also a concern. The Arctic is warming twice as fast compared to the rest of the world. The pronounced warming signal, the amplified response of the Arctic to global warming, it is often seen as a leading indicator of global warming. The melting of Greenland's ice sheet is linked to polar amplification. According to a study published in 2016, about 0.5◦C of the warming in the Arctic has been attributed to reductions in sulfate aerosols in Europe since 1980.

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." The period of 1995–2005 was the warmest decade in the Arctic since at least the 17th century, with temperatures 2 °C (3.6 °F) above the 1951–1990 average. Some regions within the Arctic have warmed even more rapidly, with Alaska and western Canada's temperature rising by 3 to 4 °C (5.40 to 7.20 °F). This warming has been caused not only by the rise in greenhouse gas concentration, but also the deposition of soot on Arctic ice. A 2013 article published in Geophysical Research Letters 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. The authors conclude that "anthropogenic increases in greenhouse gases have led to unprecedented regional warmth."

The poles of the Earth are more sensitive to any change in the planet's climate than the rest of the planet. In the face of ongoing global warming, the poles are warming faster than lower latitudes. The primary cause of this phenomenon is ice-albedo feedback, whereby melting ice uncovers darker land or ocean beneath, which then absorbs more sunlight, causing more heating. The loss of the Arctic sea ice may represent a tipping point in global warming, when 'runaway' climate change starts, but on this point the science is not yet settled. According to a 2015 study, based on computer modelling of aerosols in the atmosphere, up to 0.5 degrees Celsius of the warming observed in the Arctic between 1980 and 2005 is due to aerosol reductions in Europe.

Black carbon deposits (from the exhaust system of marine engines) reduce the albedo when deposited on snow and ice, and thus accelerate the effect of the melting of snow and sea ice.

According to a 2015 study, reductions in black carbon emissions and other minor greenhouse gases, by roughly 60 percent, could cool the Arctic up to 0.2 °C by 2050.

Sea ice is currently in decline in area, extent, and volume and may cease to exist sometime during the 21st century. Sea ice area refers to the total area covered by ice, whereas sea ice extent is the area of ocean with at least 15% sea ice, while the volume is the total amount of ice in the Arctic.

This page was last edited on 26 May 2018, at 13:53.
Reference: https://en.wikipedia.org/wiki/Climate_change_in_the_Arctic under CC BY-SA license.

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