Wednesday 4 November 2009

Climate Change: Himalayan glaciers melting fast

U Sudhakar Reddy
Himalayan glaciers are receding continuously and significantly says glaciologist Mr Rajesh Kumar of the Birla Institute of Technology (BIT) who conducted a major study on the Himalayas.
Witnessing Change: Glaciers in the Indian Himalayas, a report by WWF-India and BIT, researches the retreat patterns of two glaciers of Uttarakhand -- Gangotri (30-km long) and Kafni (4.2-km long) -- in the last couple of years.
The Gangotri is one of the largest ice bodies in the Himalayas and is a major source of fresh water.
A comparative analysis of the glacier snout position carried out using data for the past three decades found that not only the main trunk of the glacier recede, its length also reduced by 1.5 km in 66 years with an average retreat rate of 22.1 metres per year.
"The plausible reasons linked to this retreat is reduction in snowfall and increase in local temperature. There is an average loss of 0.279 square kilometre of area of glacier," Mr Kumar said.
In the past 64 years, the total area reduced is 17.84 square kilometres. This amounts to 25.33 per cent of the total glacier area since 1942.
Mr Kumar said, "This is a continuos process, though the rate of retreat fluctuated during different intervals of time."
According to the study, the Kafni glacier also retreated. "The average retreat of Kafani glacier is 16.5 metres per year in the last three decades. But it decreased later and then again increased to 15.55 metres per year in 200809," said Mr Kumar.
"The dynamics of the monsoon are influenced by the Himalayan system which acts as a reservoir to sustain agriculture, providing freshwater and ground water recharge, and is home to a unique ecosystem with many endemic species," Mr Kumar says.
Satellite images clearly show the shift in the location of glaciers since 1937, reiterating the point that 450 glaciers across the Himalayas are melting fast.
The Himalayan glaciers have reduced from 2,000 sq km to 1,600 sq km which is a reduction of 21 per cent! Glaciers such as Kafni in Himachal are shrinking at an alarming rate. Melting of these glaciers has led to drastic climatic changes such as rise in temperature and decrease in snowfall.

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