Climate: New study slashes estimate of icecap loss

Estimates of the rate of ice loss from Greenland and West Antarctica, one of the most worrying questions in the global warming debate, should be halved, according to Dutch and US scientists. In the last two years, several teams have estimated Greenland is shedding roughly 230 gigatonnes of ice, or 230 billion tonnes, per year and West Antarctica around 132 gigatonnes annually. Together, that would account for more than half of the annual three-millimetre (0.2 inch) yearly rise in sea levels, a pace that compares dramatically with 1.8mm (0.07 inches) annually in the early 1960s. But, according to the new study, published in the September issue of the journal Nature Geoscience, the ice estimates fail to correct for a phenomenon known as glacial isostatic adjustment. This is the term for the rebounding of Earth's crust following the last Ice Age...more