Arctic sea ice is thinning and cracking, say researchers on two continents. The result could mean major shifts in climate and in the polar ecosystem. In the United Kingdom, Seymour Laxon of University College London used satellite radar to study roughly half the permanent ice cover in the Arctic and found that it has thinned by 12 inches over the last eight years. His discovery jibes with recent NASA data indicating that Arctic summers are two weeks longer than they were 25 years ago.
Meanwhile, the largest ice shelf in the Arctic is breaking up, caused possibly by a rise of 1 degree Fahrenheit over the last 30 years. Using satellite radar and helicopter observations, scientists at Laval University in Quebec and the University of Alaska at Fairbanks discovered that the more-than-150-square-mile Ward Hunt Ice Shelf on the north coast of Canada’s Nunavut territory has split in half. Now large chunks of ice are floating away, and an enormous freshwater lake that floated on top of the 4,000-year-old shelf has disappeared.
The environmental tumult is diminishing the habitat for many species, from polar bears and seals to crustaceans and unique Arctic algae. And as the ice disappears, more and more sunlight will be absorbed into the dark ocean instead of being reflected. “This will contribute to temperature rises even in the lower latitudes of the Northern Hemisphere,” Laxon says.