Climate change is melting the West Antarctic Ice Sheet. A recent swell in warm ocean water on the western side of the continent is eating away at two predominant glaciers, Pine Island Glacier and Thwaites Glacier. And the retreating glaciers mean the entire larger ice sheet could disintegrate, leading to a 10-foot rise in sea level around the world. This surge in water levels imperils major coastal metropolises from New York City to Tokyo.