OSLO (Reuters) - Mountain glaciers in Central Asia have shrunk four times faster than the world average, threatening river flows vital for agriculture and hydro power from Uzbekistan to western China, scientists said on Monday.
Global warming is likely to quicken the thaw in the vast Tien Shan range in coming years, melting half the remaining ice by the 2050s, according to the study led by the GFZ German Research Centre for Geosciences.
A local rise in temperatures, perhaps linked to climate change in the north Pacific and north Atlantic oceans, means ever more precipitation is falling as rain in summertime on the Tien Shan, eroding glacier ice, the study found.
The melt is of “particular concern”, the scientists wrote in the journal Nature Geoscience, because of rapid local population growth in a region that already suffers disputes over sharing water.
The Tien Shan range, whose glaciers contain about seven times the amount of ice as the Alps or a third of the Himalayas, stretches 2,500 km (1,500 miles) through Central Asia.
Tien Shan glaciers lost 27 percent of their total mass from 1961-2012, a rate of 5.4 billion tonnes of ice a year and about four times the global average glacier loss of 6.5 percent, the study said of data from satellites and monitoring on the ground.
That meant river flows were now high, but would dwindle as the ice vanishes.
“Currently we are in the golden phase, with relatively much water,” Daniel Farinotti, lead author of the study at GFZ and the Swiss Federal Institute for Forest, Snow and Landscape Research, told Reuters.
“But what could happen is quite worrisome.”
Water from the mountains helps grow crops in lowland areas of Kazakhstan, Kyrgyzstan and Uzbekistan, one of the world’s biggest irrigated areas, and China’s north-western Xinjiang region, the experts wrote.
In 2012, Uzbek President Islam Karimov said that disputes over Central Asian water resources risked provoking military conflict, kept in check under the former Soviet Union by Moscow’s centralised management.
Kyrgyzstan, for instance, needs to use water for hydro power production in winter while Uzbekistan, downstream, wants water to stay in reservoirs and be released in summer for farmers including cotton growers.
Editing by Robin Pomeroy