Sea levels may swell much higher than previously predicted, thanks to feedback mechanisms that are speeding up ice melt in Greenland and Antarctica.
Climate simulations need to take such feedbacks into account, William Hay, a geologist at the University of Colorado Boulder, told the Geological Society of America meeting in Charlotte, N.C., on November 4. So far the models haven’t incorporated such information because “it just makes them much more complicated,” he says.
Many scientists share Hay’s concerns, says geologist Harold Wanless of the University of Miami. “The rate at which ice melt and sea level rise is happening is far faster than anything predicted,” he says.
Global sea levels rose an average of about 15 centimeters over the past century. Current data suggest they will rise another 1 meter by the year 2100, and some scientists predict far more.