Billions of people in China and the Indian subcontinent rely on South Asia's Himalayan glaciers – the world's largest store of fresh water outside the polar ice caps. The massive ice floes feed seven of the world's greatest Asian rivers in one of the world's most densely populated regions.
Yet as global climate change slowly melts glaciers from Africa to the Andes, scientists say the glaciers in the Himalayas are retreating at a rate of about 33 to 49 feet each year – faster than in any other part of the world.
In the Himalayas, the Gangotri Glacier, one of India's largest, is entitled to an even more dubious distinction. Recent studies reveal that the Gangotri, which forms a mass of ice about 18 miles long, is retreating at a rate of more than 100 feet a year.
But according to government officials and environmental groups like Greenpeace, very little has been done in the way of a rigorous scientific study. Scientists are monitoring glacial melting on only a handful of the 7,000 glaciers that cover the Indian Himalayas.
And at such a rapid retreat, a gradual increase in droughts, flash floods, and landslides are not the only issue to worry about, say environmentalists. Justwhen power companies are planning more energy sources to power India's growing economy, a rising level of sediment in regional rivers is creating havoc for many grids.
"The power grid in Uttarkashi is constantly breaking down and that's because of the rise in sediment in the water being used at the hydro-power projects," says Joseph Thsetan Gergan from the WADIA Institute of Himalayan Glaciology, a part of the Indian Department of Science and Technology. "When the power breaks down, the people blame the Geological Survey of India or the Central Water Commission for not doing its work properly, but that's like thinking of digging a well when your house is already on fire."
While the Gangotri has been retreating since measurements began in 1842, the rate of retreat, which was around 62 feet per year between 1935 and 1971, has almost doubled.
An added difficulty, says Mr. Gergan, is the lack of a sustained research effort since the 1970s. The Indian government's own recommendations, issued in March 2002 by the standing committee on Science and Technology, noted that glacial melting required immediate implementation of a program to measure and monitor the changes to the Gangotri and its impact on the Ganges river systems.
"It's not enough to just note the fact that the glaciers are melting," Gergan says. "The impact of that is not being focused on at all."
Others say the news is not all bad for India. Suruchi Bhadwal of the Energy Resources Institute, in New Delhi says that India is the first country to have a ministry for nonconventional energy sources which has big plans for the future.
"[The government plans] to electrify 70,000 villages using renewable energy, promote the use of biodiesel, and use low-carbon development pathways," Mr. Bhadwal says.
India has the potential to generate up to 45,000 megawatts of wind energy, but the country has only been able to harness about 2,980 megawatts as of 2004.
None of these lofty goals assuages environmentalists' worries, but Bhadwal is optimistic when he compares India's glaciers with those of neighboring Pakistan.
"Although India's glaciers are retreating, in Pakistan there are some that are actually growning in size," says R. Rangachari, a research professor at the Center for Policy Research, a New Delhi-based independent think tank.
But despite such scientific ambiguities, Mr. Rangachari says India's retreating glaciers can no longer be ignored – regardless of whether they are the fault of climate change or population increases along the higher reaches of the river.
"The Gangotri has been receding for about 500 years, and there is no doubt that things are worsening, whether it's climate change or anything else," Rangachari says. "But it's no good looking at recession in isolation, or population density in isolation, the problem as a whole must be urgently attended to by the government."
The Gangotri glacier terminates at a "snout," known to Indians as the Gaumukh, or cow's head. The snout forms an ice cave and becomes the source of the Bhagirathi river. Each year, millions of pilgrims take a swim in the freezing waters here in order to free themselves from their sins.
At 79, local holy man Swami Sundaranand, who lives in Gangotri – a temple town and destination for many trekkers – has been taking photos of the Gangotri glacier and the Gaumukh for more than 50 years. As a yogi, he has perfected 300 yogic positions or asanas, and climbed twice with Edmund Hillary and Tenzing Norgay. Yet it is his photographic tendencies that have earned the Swami his nickname: "Sadhu Who Clicks," after the common name for an Indian ascetic.
Armed with more than 100,000 photos as evidence of the glacier's shrinkage, the swami travels India holding press conferences to raise awareness of the Gangotri's rapid demise. "In 1949, when I first saw the glacier, I felt as if all my sins were washed away and I had truly attained rebirth," the swami says. "But now, it is impossible to experience that Ganga of the past."