The Arctic is leading a race with few winners, warming twice as fast as the rest of the Earth. Loss of snow and ice, which reflect the sun's energy, is usually blamed for the Arctic temperature spike.
But a new study suggests the Arctic's cap of cold, layered air plays a more important role in boosting polar warming than does its shrinking ice and snow cover. A layer of shallow, stagnant air acts like a lid, concentrating heat near the surface, researchers report today (Feb. 2) in the journal Nature Geoscience. [Images of Melt: Earth's Vanishing Ice]