Scientists have long known that the earth's glaciers can be read like giant, icy history books, piled with layers of clues to past climates, volcanic activity and even plant life. Over the past few years, rapidly shrinking glaciers have also become the most compelling signs of global warming.
Glaciers in the Arctic, the Alps in Europe and the Rockies in North America have been studied by countless scientists. But glaciers in the world's highest mountain range, the Himalayas, have not. Accurate and regular measurements in the Himalayas go back 15 years at most. "Glaciers are very sensitive to climate change," says D.P. Dobhal, a geologist turned glaciologist, who works for the Indian government. "But, in the Himalayas, we still know very little."
Dobhal, 45, studies what is happening to the Himalayan glaciers. He sees that they are receding, and fast. He's also trying to determine what the shrinking might mean for the millions of people who live downstream of the giant ice masses.
Dobhal uses simple bamboo stakes to measure the depth and movement of the glaciers. It's risky work, carried out at altitudes of up to 13,120 feet. He is unfazed by the danger. "Whatever I do, I'm doing for my country," he says. "I've been assigned to study certain problems, and so I work on them."
It helps that Dobhal was born in the foothills of the Himalayas. He loves the incredible peaks that loom over him as he and his team trudge up another rocky slope with their equipment. "Glaciers are the best indicator we have," he says. "It's where I need to be."