Page last updated at 16:15 GMT, Wednesday, 24 June 2009 17:15 UK

Himalayan glacier studies commence

By Navin Singh Khadka
Environment reporter, BBC News

Glacial Lake, Nepal
The studies will begin with Imja lake in the Everest region

After a long gap, scientists in Nepal have embarked on the first field studies of Himalayan glacial lakes, some of which are feared to be swelling dangerously due to global warming.

In May, they completed the field visit to the first location, a lake in the Everest region, in a series of studies.

They plan to conduct similar surveys of two other glacial lakes in the central and western part of the Nepalese Himalayas later in the year.

"We have started with Nepal, but we intend to extend studies to other Hindu Kush Himalayan countries," says Arun Bhakta Shrestha, a climate change specialist with the International Centre for Integrated Mountain Development (ICIMOD), which is carrying out the research alongside a number of government agencies.

"This is a part of our regional assessment of the floods such lakes can cause if they burst."

The Hindu Kush Himalayan region stretches between Burma in the east to Afghanistan in the west, showcasing spectacular snow-clad mountains, some of which are the world's highest.

Having returned from their first field visit, the scientists are now grappling with the data they collected on the body of water, known as Imja lake.

It will take some time before they release their final conclusions.

I was shocked to see fresh water at that altitude, where I had seen nothing but snow and ice before
Appa Sherpa, Nepal

But, sharing his initial observations, Pradeep Mool, a remote sensing specialist with the ICIMOD, said there was an air of change in and around Lake Imja.

"The area of the lake has become bigger and there are some changes in its end moraines [accumulations of debris]."

But, he added, "I would not call it alarming".

Witnessing change

While scientists are cautious when speaking about the changes, mountaineers have been more vocal.

There is talk among Sherpa climbers about what they say is fast glacial retreat and snow meltdown in the Himalayas.

Appa Sherpa, who has climbed Everest a record number of times said recently that he had seen fresh water at the height of above 8,000m on Everest.

"I was shocked to see fresh water at that altitude, where I had seen nothing but snow and ice before," he said on his return last month from his 19th climb to the highest peak.

This time he was on the Everest as a "climate witness", for green group WWF's campaign to raise awareness of the impact of climate change on the Himalayas.

Glacial Lake, Nepal
The area of Imja glacial lake has increased

It has been almost two decades since the first few field studies were done in the Himalayas. This gap in data-gathering and dearth of local climate change information has earned it the name "white spot".

Most of the studies have been desk-based, with the help of satellite imagery and computer simulations.

Such studies have shown that the average temperature in the Himalayas have been rising at the rate of 0.06C every year, fuelling fears that glaciers may be melting fast, and filling up glacial lakes.

One such study by the UN Environment Programme (Unep) and ICIMOD, nearly 10 years ago, warned that 20 glacial lakes in Nepal and 24 in Bhutan were swelling so rapidly that they could burst by 2009.

A burst lake would cause flash floods, which could sweep away buildings and roads or even whole communities in countries like Nepal and Bhutan.

This has already happened more than 30 times in and around Nepal in the last 70 years.

A glacial lake burst in Khumbu in the Everest region in 1985, washing away a hydropower station, a trekking trail and numerous bridges.

Invisible threat

There are around 3,300 glaciers in the Nepalese Himalayas and nearly 2,300 of them contain glacial lakes.

No one knows which of these are reaching breaching point. But these new field studies, starting with Imja, Thulagi and Tsho Rolpa glacial lakes, should begin to answer these important questions.

The Tsho Rolpa caused panic among locals until some water was drained from it almost ten years ago.

Khumbu Glacier, eastern Nepal
The most recent floods were caused by a glacial lake burst in Khumbu

Ever since then, the threat from glacial lakes has lurked. But funding difficulties have meant that no field studies have taken place.

Things appear to be changing now.

"We have attempted to go beyond desk-based assessments, which were largely hazard focused," says Dr Shrestha.

"We are also considering more on risk as opposed to hazard, this means we are looking at physical, economic and social aspects.

Mr Mool said it was also about bringing specialists from different fields together.

"Through the findings from these studies, we are trying to link science, policy making and public awareness so that what we find becomes practically useful for the society."

Although the field studies are specific to glacial lakes, they could also indicate how rivers in the regions might change.

Major local rivers, like the Ganges, Bramhaputra, Meghna and Indus, have most of their tributaries fed by snow melt from Himalayan glaciers.

Previous studies and computer simulations have already shown that these rivers are likely to swell significantly and cause frequent flooding as glaciers melt rapidly due to global warming.

But, according to scientists, in the long term, when the glaciers have retreated, the rivers could dry up almost entirely during the dry season.

This could cause an unprecedented crisis in the water supply for millions of people in the region.

How soon could that could happen is something these unique field studies will perhaps show.

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