From San Francisco, at a meeting of the American Geophysical Union
In today's warming climate, the significant melting of the ice sheets capping Greenland and Antarctica garners a lot of attention. However, the ongoing melting of glaciers and other small ice masses worldwide actually makes a larger contribution to the rise in sea level, a new study suggests.
Sea level is now rising about 3 millimeters each year, says W. Tad Pfeffer, a glaciologist at the University of Colorado at Boulder. While some of that increase comes from the expansion of ocean water as it gets warmer, most of the boost is caused by meltwater from land-based ice. The melting of icebergs and of the floating ice shelves that fringe Antarctica doesn't raise sea level.
Net losses of ice from Greenland and Antarctica send about 250 billion tons of water to the sea each year, Pfeffer and his colleagues estimate. However, the team's analysis of satellite and field data also finds that other