Antarctic ice loss vaster, faster than thought: study

Agence France-Presse: The East Antarctic icesheet, once seen as largely unaffected by global warming, has lost billions of tonnes of ice since 2006 and could boost sea levels in the future, according to a new study. Published Sunday in Nature Geoscience, the same study shows that the smaller but less stable West Antarctic icesheet is also shedding significant mass.

Scientists worry that rising global temperatures could trigger a rapid disintegration of West Antarctica, which holds enough frozen water to push up the global ocean watermark by about five metres (16 feet).

In 2007 the UN Intergovernmental Panel for Climate Change (IPCC) predicted sea levels would rise 18 to 59 centimetres (7.2 to 23.2 inches) by 2100, but this estimate did not factor in the potential impact of crumbling icesheets in Greenland and Antarctica. Today many of the same scientist say that even if heat-trapping CO2 emissions are curtailed, the ocean watermark is more likely to go up by nearly a metre, enough to render several small island nations unlivable and damage fertile deltas home to hundreds of millions.

…Covering the period up January 2009, the data was collected by the twin GRACE satellites, which detect mass flows in the ocean and polar regions by measuring changes in Earth's gravity field. Consistent with earlier findings based on different methods, they found that West Antarctica dumped, on average, about 132 billion tonnes of ice into the sea each year, give or take 26 billion tonnes….

Antarctic mountains and drifting ice.jpgLuigi peak on Wiencke Island, shot by Georges Nijs, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 License.