Update: New research being discussed today shows that Antarctica is warming, consistent with global temperature rise, and contrary to previous assessments that showed conflicting data about the continent's response to global warming.
Reuters, on assignment with the British Antarctic Survey, brings worrying news today: The Wilkins Ice Shelf is nearing collapse.
Floating ice shelves account for about 11% of the area of Antarctica, and while the loss of these ice shelves does not increase sea level, they effectively act as corks to hold back glaciers. Significant melting of Antarctica's glaciers -- which have been moving more rapidly toward the sea -- could increase sea levels as much as 20 feet worldwide, by some estimates.
The Wilkins Ice Shelf is part of the Antarctic Peninsula, which juts toward South America and is one of only two masses of land on the continent outside the Antarctic Circle. This portion of the continent has warmed rapidly in recent years, showing a trend similar to that seen in the Arctic. (Other trends across Antarctica have been less consistent, owing in part to the ozone hole, which counteracts the greenhouse effect.)
Vast portions of the Wilkins Ice Shelf, still roughly the size of Connecticut, have already disintegrated, after 1,500 years of stability. The remaining two-thirds of the ice shelf could collapse at any time, as the Antarctic summer continues. The accelerated melting of Antarctica has not been factored into United Nations projections of world sea-level rise due to global warming.
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