This year, scientists reported alarming news about the huge continental ice sheet covering the western portion of Antarctica: It's headed for collapse, due to rapid melting of some of its buttressing ice shelves. When it does, global sea levels will rise by several meters. It has long been suspected that warm ocean waters at the base of those floating ice shelves are responsible for hurrying things along. But with scant data from the waters around Antarctica, that has been difficult to prove. Now, a new study that pieces together 40 years’ worth of data collected in multiple regions around Antarctica suggests that scientists have found the smoking gun: Warming waters are indeed sneaking up under the floating ice in the regions of fastest melting.
Many questions about Antarctic climate-ocean-ice feedbacks remain, however. The places where warm waters are promoting melting are powerfully linked to current wind patterns around Antarctica—and these are also subject to change in a warming world.