Glaciers in the Himalayas melting at rapid rate
Nations debate cuts in 'greenhouse' gases this week, while pace of icemelt increases.
NEW DELHI — The 1,000-year-old Hemis Buddhist monastery in Ladakh is one of the world's oldest and most famous. Yet in August, amid rain, floods, mudslides, and spillover from the Indus River, three walls of the monastery in the north India mountains began to crumble.
Why all the water - since this region has always been arid and desert-like, with an average annual rainfall of four inches?
If you are one of a group of concerned climatologists and environmentalists, one reason is a rapid rise in the melting rate of the Himalayan glaciers.
Those glaciers, some 15,000 of them, constitute the largest body of ice in the world, apart from the two polar caps. Their runoff feeds two of the oldest rivers in the world, the Indus and the Ganges - whose tributaries carry precious water for 500 million people on the northern Indian plains.
Crops, drinking water, sacred rites, village life - the organizing elements of an agricultural society - would be turned upside down if the rivers didn't flow or are reduced to a trickle.
For years now, glaciers from Patagonia to the Swiss Alps have been watched for melt because of "greenhouse" gases and the reputed global warming effect. But in South Asia, the question is not if the ice is melting - but how fast.
While many ill-effects of global warming may become acute late next century, the meltwater in Nepal, India, Pakistan, China, and Bhutan could bring problems much sooner.
"Glaciers in the Himalayas are receding faster than in any other part of the world," according to a study by the International Commission for Snow and Ice (ICSI). "If the present rate continues, the likelihood of them disappearing by the year 2035 is very high."
"Even if the waters dry up over 60 to 100 years, that is an eco-disaster of stunning proportions," says Syed Iqbal Hasnain, the head of ICSI, and a leading professor of environment at Jawaharlal Nehru University in New Delhi.
Scientists warn of an initial period of flooding and of the bursting of glacial lakes that now collect melting water. Too much melt, and the waters burst past unstable walls of rock and silt called moraines - potentially causing mudslides. But once the lakes are emptied, rivers would shrink.
The eastern Himalayas, which sit in the Ganga basin, have the severest melts. Due to unusual monsoon patterns, and possibly to global warming, those glaciers on the "roof of the world" from Bhutan to Kashmir are shrinking fastest. Instead of winter snows that allow glaciers to accumulate bulk, the summer monsoon rains are pelting the glaciers, causing them to melt.
Take the three-mile long Dokriani Barnak glacier, one of the many formed after the Indian subcontinent collided with the Asian landmass 40 million to 50 million years ago. The glacier is one of the most studied in the world. Since 1990 it has receded a half mile. After a numbing sub-arctic winter in 1997, scientists expected Dokriani to expand. Instead, in the summer of 1998, it receded farther.
"That is a phenomenal melt rate," Joseph Gergan of the Wadia Institute of Himalayan Geology told Science magazine. The rate was high again this year.
How much warmer the monsoon rains are as a result of global warming, and how much thicker they fall, is a matter of debate. Scientists disagree over the actual causes of melting glaciers and to what degree the greenhouse gases are responsible.
Since the Little Ice Age" that lasted from 1430 to about 1850, global temperatures have risen. In the past 30 years, the earth's overall average temperature has increased by 5 degrees F., by some estimates. In Bonn this week, the environmental ministers from around the world met to set targets for cutting pollution. Syeda Sajeda Chowdhury, Bangladesh's minister for environment and forests, said that nearly 20 percent of her country could be under water in 15 years if global warming isn't controlled.
"The Indus rose to unprecedented levels this summer, and one reason is glacial melt," says Kathleen McGinty, a former aide to Vice President Al Gore and a fellow at the Tata Energy Research Institute in New Delhi, who visited Ladakh this summer. "We can't say that greenhouse gases are the main reason. But we can say that the melt is consistent with a global pattern that marks the signature of climate change."
Yet some scientists scoff. They say the sky is not falling - or, in the case of the Himalayas, melting. ICSA officials argue that some 2,000 of the 10,000 eastern Himalayan glaciers have melted in the last century. Others say the number is wildly exaggerated. "To attract attention to the issue, some scientists make dramatic statements," says one Delhi-based climatologist who requested anonymity. "These glacial data are early warnings and need to be taken seriously. But the boundaries of glaciers are never fixed. They recede, but they also expand. It is far too early to judge. No one has really studied the problem thoroughly."
Exactly, says Ms. McGinty. "That is why I use the old adage, 'Never let common sense get in the way of another study.' "
Lack of data stems from little cooperation between politicians and scientists in the region. Pakistan doesn't cooperate with India. Bhutan is still largely a closed society. What is needed is a satellite study from above, some say. That possibility is on the way, compliments of NASA and the US Geological Survey. During the first week of December, a satellite devoted to observing the Ganga plains will be launched.
(c) Copyright 1999. The Christian Science Publishing Society