But some of the most devastating effects of glacier meltdown occur when glacial lakes overflow. These lakes, which are formed throughout the mountain range by melting glaciers, threaten to flood entire valleys, putting tens of thousands of people's lives at risk. For decades glacier ice and debris have acted like natural dams to contain the growing lakes. But when melting glaciers feed the lakes faster than water can drain, a violent torrent of liquid and debris often escapes as pressure in the burgeoning lake causes it to literally push past the glacier, ice or debris that holds it back. The chances of a glacial lake outburst increases in the summer, when glaciers melt, and rainwater from the monsoon season adds pressure to the swelling lakes, according to Paul Mayewski, director of the Climate Change Research Center at the University of New Hampshire.
Scientists also say that global warming has accelerated the formation of glacial lakes.
If scientists are right and the warming persists, my family and many people living in the valley will be the first victims. Teiji Watanabe, a geomorphologist who has monitored Himalayan glaciers for more than 10 years predicts that the Imja glacier lake will experience an outburst within the next five years, placing the lives of thousands of isolated villagers in danger. Landslides, floods and avalanches plague villages at the foot of the Himalayas. But the Imja is not the only glacial lake threatening the people of the Himalayas. Last year, experts warned that the Tsho Rolpa lake in Nepal could burst its banks.