for National Geographic News
Dozens of mountain lakes in Nepal and Bhutan are so swollen from melting
glaciers that they could burst their seams in the next five years and
devastate many Himalayan villages, warns a new report from the United
It's hardly news that the world's glaciers are meltinga phenomenon widely attributed to gradually rising global temperatures. But the possible consequences in terms of human deaths and loss of property have reached greater urgency in light of the findings of the new study.
It was conducted by scientists from the United Nations Environment Program (UNEP), headquartered in Nairobi, Kenya, along with remote-sensing experts from the International Center for Integrated Mountain Development (ICIMOD) in Katmandu, Nepal.
They predict that in the next half a decade or so, the Himalayas could experience intense flooding as mountain lakes overflow with water from melting glaciers and snowfields.
The lives of tens of thousands of people who live high in the mountains and in downstream communities could be at severe risk as the mud walls of the lakes collapse under the pressure of the extra water. Major loss of land and other property would aggravate poverty and hardship in the region.
The new flood warning is based on three years of research involving site visits and studies of topographical maps, satellite images, and aerial photography. The scientists assessed the conditions of about 4,000 glaciers and 5,000 glacial lakes in Nepal and Bhutan.
"Our findings indicate that 20 glacial lakes in Nepal and 24 in Bhutan have become potentially dangerous as a result of climate change," said Surendra Shrestha, Asian regional coordinator of the UNEP's Division of Early Warning and Assessment, which is based in Bangkok, Thailand.
Bigger Threat Unknown
The researchers say that the 44 lakes they identified as potentially dangerous in the near future is a conservative estimate of the number of sites that may pose a serious threat.
"These are the ones we know about," said Shrestha. "Who knows how many others, elsewhere in the Himalayas and across the world, are in a similar critical state?"
The UNEP-ICIMOD study focused only on the two small land-locked countries of Nepal and Bhutan. The team says it looked at these countries earlier than others since the governments of Bhutan and Nepal requested them to do so. In the second phase, the work is being expanded to include Pakistan, China, and countries in central Asia.
Negotiations begin this month to extend the study to India. The largest part of the Himalayas lies within India, although "almost nothing is known about glacial lake outburst floods from India," said Sarfaraz Ahmed, a glacier expert at the School of Environmental Sciences at Jawaharlal Nehru University in New Delhi.
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