A nearly ice-free Arctic Ocean in the summer may happen three times sooner than scientists have estimated. New research says the Arctic might lose most of its ice cover in summer in as few as 30 years instead of the end of the century. The amount of the Arctic Ocean covered by ice at the end of summer by then could be only about 1 million square kilometers, or about 390,000 square miles. That’s compared to today’s ice extent of 4.6 million square kilometers, or 1.8 million square miles. So much more open water could be a boon for shipping and for extracting minerals and oil from the seabed, but it raises the question of ecosystem upheaval. While the Intergovernmental Panel on Climate Change in 2007 assessed what might happen in the Arctic in the future based on results from more than a dozen global climate models, two researchers reasoned that dramatic declines in the extent of ice at the end of summer in 2007 and 2008 called for a different approach. Out of the 23 models now available, the new projections are based on the six most suited for assessing sea ice, according to Muyin […]