Recent ice loss in East Antarctica not accounted for in SCAR report
Posted December 18, 2009
A study published in November that suggested the East Antarctic Ice Sheet might be losing ice to the ocean did not make it into a major new climate report produced by the Scientific Committee on Antarctic Research (SCAR) this month.
Using data from a joint NASA-German satellite mission, researchers from the University of Texas at Austin determined that the ice sheet is losing mass, mostly in coastal regions, at an estimated rate of 57 gigatonnes a year. A gigatonne is one billion metric tons, or more than 2.2 trillion pounds.
Scientists already know the marine-based West Antarctic Ice Sheet is contributing to sea level rise, its stability more at risk because much the bedrock it sits upon is under water. Now they may have to account for the larger, thicker East Antarctic Ice Sheet, which contains enough ice to raise sea level by as much as 60 meters.
Robert Bindschadler , an editor on the SCAR report, said the continent is changing so rapidly that it’s impossible to account for all the new data that emerge.
“It’s like buying a computer. The minute you’ve got your computer at home it’s out of date,” noted Bindschadler, chief scientist of the Hydrospheric and Biospheric Sciences Laboratory at NASA’s Goddard Space Flight Center .
“When things are changing so fast — and this is one of those situations where the Antarctic is changing really fast — [the SCAR report] is unable to include the latest reports and measurements,” he added.
The December report from SCAR, Antarctic Climate Change and the Environment (ACCE) , provides an important baseline for assessing future changes to the continent and the surrounding Southern Ocean, according to Bindschadler.
The SCAR editors believe the document will also be valuable to the authors of the next Intergovernmental Panel on Climate Change (IPCC) report, due out in 2014. The 2007 IPCC report largely lacked any data on Antarctic, and its projections for sea level rise did not include ice loss from the southern continent.
The IPCC report suggested a sea level rise of about half a meter by 2100. The SCAR report nearly triples that estimate, with “tens of centimeters” coming from the West Antarctic Ice Sheet over the next century.
“For the next IPCC, this is a report that makes it easier to see the full breadth of Antarctic research,” Bindschadler said. “In that sense, I think it will help the authors of the next IPCC document.”
Paul Mayewski , another editor on the SCAR report and director of the Climate Change Institute at the University of Maine , said the document also shows the significance of Antarctica and the Southern Ocean to the rest of the world.
“That was another reason for preparing this document,” he said. “To get out to the rest of the scientific community and the public an understanding of what is going on today in Antarctica, what are the best estimates for climate projection in the future, so we can now begin to couple what’s happening in the Antarctic with what’s happening” in the rest of the world.
Return to main story: State of the Antarctic