MISSION // ESCAPE THE FLOOD

AFTER 45 YEARS OF TEACHING, most tenured academics are thinking about going fishing. But Shroder, 66, a geography and geology prof at the University of Nebraska at Omaha, is too nervous to slow down. Since 1983, the rock maven has led nearly 20 scientific expeditions to the Himalayas. His frightening discovery? Thousands of the region's people are living under the threat of imminent global-warming-triggered floods. The danger is caused by "debuttressing," a process in which rising temperatures cause glaciers propping up near-vertical rock walls to melt until the walls collapse. The resulting domino effect can be lethal: Rockslides dam runoff, forming lakes that swell until they burst and unleash floods on communities downstream. To thwart such disasters, Shroder has set up a warning center in Omaha, where he studies satellite images and alerts Himalayan authorities to coming floods. He's also coordinating the first workshop between Indian and Pakistani geoscientists. In July, Shroder saw the scenario unfolding near Pakistan's 28,250-foot K2, where a glacial lake had begun to leak. He says, "Now we're just waiting for the other shoe to drop."