Arctic sea ice is disappearing at a far greater rate than previously expected, about 50% higher than most predictions, according to data from the first satellite launched to study the thickness of the Earth’s polar caps, reports Robin McKie at the UK Guardian. 900 cubic kilometres of summer sea ice has disappeared from the Arctic ocean over the past year, according to the European Space Agency’s probe. This much higher loss rate indicates that global warming is beginning to have a major impact there. In a few years the Arctic summer ocean could be ice-free. Although the area of ice has been decreasing rapidly, new data shows that remaining ice has been thinning dramatically. Areas north of Canada and Greenland, for example, where summer ice was normally five to six metres thick a decade ago, have now thinned to one to three metres. Losing Arctic summer ice would further speed up Arctic heating, likely causing oceanic methane deposits to melt faster, evaporate into the atmosphere, and accelerate global warming more. This could further destabilize the jet stream, and increase extreme weather in lower latitudes, like that experienced this year.
Rate of arctic summer sea ice loss is 50 percent higher than predicted. Sea ice in the Arctic is disappearing at a far greater rate than previously expected, according to data from the first purpose-built satellite launched to study the thickness of the Earth’s polar caps. http://www.guardian.co.uk/environment/2012/aug/11/arctic-sea-ice-vanishing