Arctic Ice by Canada and Greenland80.8N 71.4W
This image shows glacial ice and sea ice in the Arctic, between Canada and Greenland. Effects of Arctic climate change include a marked decrease in Arctic sea ice; thawing permafrost, leading to the release of methane, a potent greenhouse gas; the release of methane from clathrates, leading to longer time-scale methane release; the observed increase in melt on the Greenland Ice Sheet in recent years; and potential changes in patterns of ocean circulation.
Scientists worry that some of these effects may cause positive feedbacks which could accelerate the rate of global warming. The sea ice in the Arctic region is in itself important in maintaining global climate due to its albedo (reflectivity). Melting of this sea ice will therefore exacerbate global warming due to positive feedback effects, where warming creates more warming by increased solar absorption.