The glaciers in Asia's Tian Shan mountains have lost more than a quarter of their total mass over the past 50 years — a rate of loss about four times greater than the global average during that time, new research shows.
By 2050, half of the remaining ice in the Tian Shan (also spelled Tien Shan) glaciers could be lost, and these shrinking glaciers could reduce valuable water supplies in central Asia and lead to fuel conflicts there, the study found.
The Tian Shan mountain range stretches across 1,550 miles (2,500 kilometers) of central Asia. Melting snow and glaciers from these mountains supply much-needed water to the lowlands of Kazakhstan, Kyrgyzstan and Uzbekistan, which form one of the world's largest irrigated zones. The melt also supplies water to China's northwestern Xinjiang Uyghur autonomous region, whose coal, oil and natural-gas reserves are critical to the country's economic growth. [See Photos of the World's 10 Tallest Mountains]
"If water resources really will decline there in the future, there is a big potential for conflicts," said the study's lead author, Daniel Farinotti, a glaciologist at the German Research Center for Geosciences and the Swiss Federal Institute for Forest, Snow and Landscape Research.
Despite the importance of this water supply and the growth of populations dependent on it, information about the conditions of glaciers in the Tian Shan is sparse, and estimates of how these glaciers might change in the future have been limited to the past decade.
To learn more about the Tian Shan glaciers, Farinotti and his colleagues analyzed data from the Gravity Recovery And Climate Experiment (GRACE), a satellite launched in 2002 that is jointly operated by NASA and the German Aerospace Center; and NASA's Ice, Cloud and Land Elevation Satellite (ICESat), which launched in 2003. They also developed computer models of these glaciers based on field observations from snow pits and readings taken from glacier surfaces.
The scientists reconstructed how glaciers across the Tian Shan changed in mass from 1961 to 2012. They found that the region's glaciers shrank at the rapid rate of about 5.4 billion tons per year on average.
The researchers linked the decline to increased summer temperatures in the region, possibly due to climate change. "In central Asia, you have really dry winters, meaning glaciers do not get much snow then," Farinotti told Live Science. "During the summer, at higher elevations, it will snow. However, if you see increasing summer temperatures in central Asia, not only will you get increased melting, but you'll also reduce the amount of snow they'll get, for a double impact."
Climate models suggest that summer temperatures will continue to rise in the coming decades, suggesting that the glaciers in the Tian Shan may shrink even further.
"In the long term, the only way people are going to save glaciers is to reduce the increase of global temperatures," Farinotti said. "Another way to deal with the decline in water supplies in this region is to improve irrigation practices there. Irrigation there dates back to the Soviet era 40 years ago, and increasing the efficiency of irrigation there could help grow crops even with less water."
The scientists detailed their findings online today (Aug. 17) in the journal Nature Geoscience.
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