Glacial Flooding: Another Threat of Global Warming
Posted by greendistrict
For years, I had heard about how glacier melting caused by global warming was imperiling the world’s fresh water supplies, the vast majority of which come from mountains. But I hadn’t thought about the flooding threat the rapid melting poses to mountain communities until I listened to presentations by mountain geographer Alton Byers and Nepalese mountaineers Apa Sherpa and Dawa Steven Sherpa last week in Italy.
A quick search of the Internet, provides plenty more detail on this phenomenon, known as a glacial lake outburst. Here in the United States, lakes formed by melting glaciers on Mount Rainier in Washington State have burst their banks, causing flooding several times in the last quarter century. Alaska and Wyoming, among other places, have also seen flooding caused by the failure of glacial lakes. But rural mountain communities in the Himalayas are among the most endangered in the world. The United Nations Environment Program has an inventory of these potentially dangerous water bodies in the Himalayan countries of Nepal, Bhutan, Pakistan and parts of India and China.
It’s not a new phenomenon. Apa Sherpa lost his farm in the sudden August 1985 outburst from the Dig Tsho glacial lake in Nepal that destroyed fourteen bridges and caused $1.5 million in damage to a nearly finished hydropower plant. Since then, experts have seen a rising number of similar flooding disasters.
The UN estimates that tens of thousands of lives are at risk in the Himalayas alone as rising temperatures accelerate the melting. It is one of several threats the rapid retreat of glaciers is causing in these and other mountainous countries from Peru to Switzerland. Besides flooding, these countries area already reporting declines in fresh water supplies used for drinking and irrigating crops. Experts estimate that a billion people around the world live in river basins fed by glaciers and melted snow. And, hydroelectric power is also expected to decline sharply as the melting continues in coming decades.
Efforts to solve the problem are also underway. In Bhutan, the government received help earlier this year from international groups to drain Thorthormi Tsho lake before it could flood the valley below it. The operation has been held up as an example of how glacial countries might adapt to climate change.
Peru, which has dealt with the problem for decades, has developed ways to drain these lakes and harness hydroelectric power from the melt water, Byers says. He is now working with Peruvian officials to bring the knowhow to Nepal, where about two dozen glacial lakes are considered critically dangerous and more will likely form as the world’s glaciers disappear by or before the end of the century.
“We don’t want to move. We want to stay and solve this problem,” Dawa Steven Sherpa told journalists at GreenAccord last week. He recalled hearing his grandfather talk about how it was once possible to cross a glacial mountain pass connecting Nepal to Tibet on the other side of Mount Everest. Today, that snow and ice are gone and way impassable. Long established climbing routes have also disappeared elsewhere in the region, exposing rock and rubble and making climbing more treacherous, he said.
To draw attention to global warming ahead of next week’s international climate talks in Copenhagen, Nepal’s Cabinet is meeting this week at the Mount Everest base camp, 17,192 feet (5,240 meters) above sea level. Dawa and Apa Sherpa, meanwhile, are heading to Copenhagen, where they plan to join other activists for a Dec. 11 march.
“This is not a problem we can run away from,” according to Dawa Sherpa. “This is a problem we are going to have to face head on and solve.”
About greendistrictI'm Christine MacDonald, a journalist and the author of the book: "Green, Inc., An Environmental Insider Reveals How a Good Cause Has Gone B
Posted on December 2, 2009, in Climate Change, Global Warming and tagged Climate Change, Climate Change. Tags: Apa Sherpa, Dawa Sherpa, glacial lake outburst, glacial lakes, glaciers, Global Warming, GreenAccord, hydro electricity, Italy, Landucci, Mount Everest, mountain climbing, Nepal, Sherpa, Viterbo, water. Bookmark the permalink. 2 Comments.