The Heat Is Online

West Antarctica melting twice as fast as projected

Antarctic Temperatures Are Rising Twice As Fast As Previously Predicted

Forbes.com, Dec. 24, 2012

West Antarctic temperatures are rising twice as fast as previously estimated, according to new research published in Nature Geoscience. Temperature records compiled from the Byrd Research Station show that since 1958, the region has seen average temperature increases of 2.4 degrees Celsius (4.3 degrees Fahrenheit). That poses a danger of causing sea levels to rise even faster than previously predicted.

“Our record suggests that continued summer warming in West Antarctica could upset the surface mass balance of the ice sheet, so that the region could make an even bigger contribution to sea level rise than it already does,” said lead researcher David Bromwich in a press release. “Even without generating significant mass loss directly, surface melting on the WAIS could contribute to sea level indirectly, by weakening the West Antarctic ice shelves that restrain the region’s natural ice flow into the ocean.”

To compile the new temperature records, the researchers took existing data from the Byrd Research Station and filled in the gaps through advanced mathematical techniques and computer modeling. The new findings are more consistent with wider global temperature trends.

Researcher Andrew Monaghan noted in the release that the new findings put the West Antarctic Ice Sheet at one of the fastest-melting sheets on Earth. ”We’ve already seen enhanced surface melting contribute to the breakup of the Antarctic’s Larsen B Ice Shelf, where glaciers at the edge discharged massive sections of ice into the ocean that contributed to sea level rise. The stakes would be much higher if a similar event occurred to an ice shelf restraining one of the enormous WAIS glaciers.”

Writing in Real Climate, research Eric Steig highlighted the importance of these results because they provide a more complete record of Antarctic ice melt. “Bromwich et al.’s updated record for Byrd Station should now be routinely incorporated into global temperature compilations such as those done by GISS and CRU. Doing so will, I think, change the picture of climate change in the Southern Hemisphere, and not insignificantly.”

Another aspect of the research, Steig continued, is that “ it shows that there is significant warming even in summer time in West Antarctica. This could arguably bode ill for the West Antarctic Ice Sheet, since if current trends continue it will mean more melting on the ice shelves there — ultimately leading to their collapse, as has already happened on the Antarctic Peninsula.”

This study adds to a number of studies this year that have shown that previous predictions of the rate of ice melt at both poles, which are considered “alarmist” in some quarters, were in fact far too conservative. Arctic permafrost is also experiencing  faster than predicted melts. Additionally, recent research has also demonstrated that sea levels are rising about 60% faster than previously predicted.

http://www.forbes.com/sites/alexknapp/2012/12/24/antarctic-temperatures-are-rising-twice-as-fast-as-previously-predicted/