Posted on September 21, 2012 by Stephen Herrmann
The August 2012 preliminary results from the European Space Agency’s CryoSat-2 probe indicate that 900 cubic kilometers of summer sea ice has disappeared from the Arctic ocean over the past year. This rate of loss is 50% higher than most scenarios from historic information outlined by polar scientists. The summer figures provide a real shock. In 2004 there were about 13,000 cubic kilometers of summer sea ice in the Arctic — now only 7,000 cubic kilometers were measured. If the current annual loss of around 900 cubic kilometers continues, summer ice coverage could disappear in about a decade in the Arctic.
The new sea ice measurement was set on August 26, 2012, a full three weeks before the usual end of the melting season, according to the National Snow and Ice Data Center. So more melt in 2012 is predicted. Every major scientific institution that tracks Arctic sea ice agrees that new records for low ice area, extent, and volume have been set. These organizations include the University of Washington Polar Science Center (a new record for low ice volume), the Nansen Environmental & Remote Sensing Center in Norway, and the University of Illinois Cryosphere Today.
The consequences of losing the Arctic’s sea ice coverage, even for only part of the year, could be profound. Without the cap’s white brilliance to reflect sunlight back into space, the region will heat up even more than at present. As a result, ocean temperatures will rise and methane deposits on the ocean floor could melt, evaporate and bubble into the atmosphere. Scientists have recently reported evidence that methane plumes are now appearing in many areas. Methane is a particularly powerful greenhouse gas and rising levels of it in the atmosphere are only likely to accelerate global warming. And, with the disappearance of sea ice around the shores of Greenland, its glaciers will melt faster and raise sea levels even more rapidly than previously predicted.