Thursday, June 11, 2009
Posted by Ali Raza

:en:Humid Continental climate zones of the world.


Climate change






The Arctic is especially vulnerable to the effects of global warming, as has become apparent in the melting sea ice in recent years. Climate models predict much greater warming in the Arctic than the global average, resulting in significant international attention to the region. In particular, there are concerns that Arctic shrinkage, a consequence of melting glaciers and other ice in Greenland, could soon contribute to a substantial rise in sea levels worldwide] Climate models give a range of predictions of Arctic sea ice loss, showing near-complete to complete loss in September anywhere from 2040 to some time well beyond 2100. About half of the analyzed models show near-complete to complete sea ice loss in September by the year 2100.

Arctic temperatures from Satellite Data 1981-2007Image via Wikipedia

In September 2008, the extent of the summer Arctic ice cap was at a near-record low, only 9 percent greater than the record low in 2007, and 33.6 percent below the average extent of sea ice from 1979 to 2000.

The current Arctic shrinkage is leading to fears of Arctic methane release. Release of methane stored in permafrost could cause abrupt and severe global warming, as methane is a potent greenhouse gas. On millennial time-scales, decomposition of methane hydrates in the Arctic seabed could also amplify global warming. Previous methane release events have been linked to the great dying, a mass extinction event at the boundary of the Permian and Triassic, and the Paleocene-Eocene thermal maximum, in which temperatures abruptly increased.

Apart from concerns regarding the detrimental effects of warming in the Arctic, some potential opportunities have gained attention as well. However, it should be noted that these advantages are minor compared to the harm which would result if a runaway global warming event

Arctic Sea Ice ComparisonImage by climatesafety via Flickr

were to occur. The melting of the ice is making the Northwest passage, the shipping routes through the northernmost latitudes, more navigable, raising the possibility that the Arctic region will become a prime trade route.In addition, it is believed that the Arctic seabed may contain substantial oil fields which may become accessible if the ice covering them melts. These factors have led to recent international debates as to which nations can claim sovereignty or ownership over the waters

Map of the sea ice in the Arctic in march and ...Image via Wikipedia

of the Arctic.

The National Oceanic and Atmospheric Administration's Arctic Report Card presents annually-updated, peer-reviewed information on recent observations of environmental conditions in the Arctic relative to historical records. In 2008, there continues to be widespread and, in some cases, dramatic evidence of an overall warming of the Arctic system.














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