Thursday, May 19, 2016

Antarctica At Tipping Point

high resolution image of Thwaites
Two recent scientific studies indicate that Western Antarctica's ice sheet has reached the tipping point of irreversible melting. The good news is that it may take 200 to a thousand years for Earth's sea levels to rise by 12-15 feet. There has been much scientific speculation recently that a melting process was underway in Antarctica, but a study published in Science confirms the Thwaites Glacier is rapidly melting. This glacier alone will raise sea levels by two feet. Thwaites holds back the remainder of the land-based West Antarctic ice sheet and once Thwaites is gone there is nothing to stop it from melting into the sea raising levels another 10-13 feet. The Thwaites study is complemented and confirmed by NASA's investigation of other glaciers in the area published in Geophysical Letters. The studies do not include the massive Greenland ice sheet, also undergoing melting. These latest results make the benchmark IPCC report on sea level rise obsolete. It estimated a rise of only 0.28-1.0 meter by 2100. However stronger winds, perhaps due to the ozone hole, have driven warmer water into the glaciers, accelerating melting and undermining their hold on the continent.