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.
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.