New data collected by scientists at Jawaharlal Nehru University in Delhi shows that glaciers in the Himalayas are retreating faster than anywhere else on Earth. Together with those on the neighbouring Tibetan mountain plateau, the Himalayan glaciers make up the largest body of ice outside the polar caps.
Now there are fears that as the glaciers retreat, the meltwater will produce catas- trophic flooding as mountain lakes overflow.
Nepal's Saramartha national park, which is popular with Western trekkers, holds the Imja glacier lake which has been growing for the past 30 years. Such meltwater lakes build up behind the mound of debris and rock, known as a moraine, left behind as the solid glacier retreats.
The Imja glacier lake now holds 30 million cubic metres of water - and researchers think it could burst its banks within five years, according to a report described in today's New Scientist magazine.
"The moraine is unstable," Syed Hasnain, the principal author of the new report, said. "Occasionally these lakes burst, releasing enormous amounts of water."
In August 1985 scores of people died in the Khumbal Himal region of Nepal when a moraine breach let a wall of water 15 metres high pour down a mountain valley. Villagers were drowned in their homes and a hydroelectric plant was wrecked.
"All the glaciers in the middle Himalayas are retreating," said Professor Hasnain, who warns that glaciers could disappear from the central and eastern Himalayas by 2035.
The report, which took four years to prepare, will be presented in July to the International Commission on Snow and Ice. Last year, research by a team at the University of Colorado, in Boulder, found that mountain glaciers everywhere were in retreat.
The Alps have lost about 50 per cent of their ice in the past century, while 14 of 27 glaciers that existed in Spain in 1980 have disappeared.
The largest glacier on Mt Kenya has shrunk by eight per cent in the last 100 years, while those on Mt Kilimanjaro, also in Kenya, are only a quarter as big.