A. 3 to 5 feet — contributing to an increasingly likely total sea level rise of more than 5 feet by 2100, a rise that will be all but impossible to stop if we don’t sharply reverse CO2 emissions trends within a decade or so.
West Antarctica’s collapsing ice shelves are in the news today. This post will survey what we now know about this unstable ice sheet and the threat it poses to humanity — or is that the threat humanity poses to it? — if we continue on our current suicidal emissions path.
Antarctica is disintegrating much faster than almost anybody imagined. In 2001, the IPCC “consensus” said neither Greenland nor Antarctica would lose significant mass by 2100. They both already are. As Penn State climatologist Richard Alley said in March 2006, the ice sheets appear to be shrinking “100 years ahead of schedule.”
A 2007 study found “The current loss of mass from the Amundsen Sea embayment of the West Antarctic ice sheet [WAIS] is equivalent to that from the entire Greenland ice sheet” (see the new survey report Antarctic Climate Change and the Environment draft here). And WAIS’s 2007′s ice loss was 75% higher than 2006′s (see “The Antarctic ice sheet hits the fan“).
On Saturday, Reuters reported on a major new study on Antarctic ice shelves, “Coastal-Change and Glaciological Map of the Larsen Ice Shelf Area, Antarctica: 1940-2005“: