January 17, 2009

Shrinking Tibetan Glacier Threatens Water Shortages

Roughly 2 billion Asians will experience water shortages in the coming decades as global warming diminishes glaciers on the Tibetan Plateau, scientists warned on Friday.

The plateau has more than 45,000 glaciers that accumulate during the region's snowy season, before they drain into Asia's main rivers, which include the Yellow, Yangtze, Brahmanputra and Mekong. Some scientists refer to the plateau as the "Third Pole" due to its massive glacial ice sheets.

However, temperatures on the plateau are rising at twice the rate of other parts of the world, according Lonnie Thompson, an Ohio State University glaciologist who for decades has gathered ice cores from glaciers around the world.

As these higher temperatures cause the glaciers to melt at faster rates, Asians have developed a false sense of security about the area's water supplies, he said.

Should the melting continue at current levels, two-thirds of the plateau's glaciers will likely disappear by 2050, he said during a meeting on climate change at the Asia Society in Manhattan.

However, those who depend on the water will begin to see dwindling supplies long before then, he said.

"The scary thing is that a lot of structures, cities and lifestyles that have been developed in the region over the last 100 years were based on an abundance of water," Thompson said.

Nearly 2 billion people in India, China, Pakistan, Bangladesh and Bhutan would experience water shortages as the rivers slow, said Geoff Dabelko, director of the environment and security program at the Woodrow Wilson International Center for Scholars, during an interview with Reuters.

Himalayan Nomads who depend upon yaks for food will also be threatened as deserts have already encroached on the yaks' grasslands, said filmmaker Michael Zhao, who has worked in the region.

Rising sea levels from the melt could also affect eastern China's coastal cities. And the shortages could even lead to new wars over the region's scarce resources, Robert Barnette, a professor of Tibetan studies at Columbia University, said at the meeting.

In some cases, dams built to contain the melted water can help.  However, these are typically substandard solutions due to local opposition from residents and people downstream from the structures, said Thompson.

The scientists said a worldwide agreement to reduce greenhouse gas emissions from tailpipes, smokestacks and the burning of forests could ultimately help slow the melting.


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