Why is the Arctic sea ice is shrinking?
Warmer air and water temperatures due to global warming Annual average surface temperature has increased about 1° C since 1980 over the Arctic, which accounts for much of the sea ice melt. In addition, some melting has occurred from beneath the ice, due to warmer ocean waters. Global warming has heated up both the North Pacific and North Atlantic waters significantly over the past 30 years. Warmer waters have been brought into the Arctic Ocean from the Pacific via an ocean current flowing through the Bering Strait between Alaska and Russia, and from the Atlantic via an ocean current flowing northwards along the European coast. Long-term natural temperature oscillations Long-term natural temperature oscillations in the Arctic may be contributing to the current sea ice decline. Divine and Dick (2006) studied records of the Arctic sea ice edge from 1750 to present, taken from shipping records in the Nordic Seas north of Europe. They found that a natural cycle with a period of 60-80 years