Melting glaciers will shrink harvests in India, China

Tomorrow is World Water Day and yet the news about water isn't heartening, according to Lester Brown (as reported in Thaindian News): Shrinking Himalayan glaciers will turn the Ganga in India and the Yangtze in China into seasonal rivers that dry up in summers, massively reducing grain harvests, and may cause “politically unmanageable food shortages” in the region, a leading US environmental expert has warned. Climate-driven shrinkage of river-based irrigation water supplies in China and India, which produce half of the world’s wheat and rice, could be “civilisation-threatening”. The scary scenario can become a reality sooner than projected so far, said Lester Brown, founder and president of Washington-based Earth Policy Institute.

“The world has never faced such a predictably massive threat to food production as that posed by the melting mountain glaciers of Asia,” he said in a paper released Thursday.

With grain prices climbing recently to record highs, any disruption of the wheat or rice harvests due to water shortages in China and India will greatly affect not only people living there but consumers everywhere, Brown said. He further projected that in both these countries, food prices will likely rise and grain consumption per person can be expected to fall. In India, where just over 40 percent of all children under five years of age are underweight and undernourished, “hunger will intensify and child mortality will likely climb”, he said.

...If the giant Gangotri glacier that supplies 70 percent of the Ganga flow during the dry season disappears, the Ganga would not flow during the summer dry season when irrigation water needs are greatest, he projected. Ganga is a leading source of water for the 407 million people living in the Gangetic basin.

Brown then quotes Chinese glaciologist Yao Tandong to say that two-thirds of the glaciers on the Tibet-Qinghai Plateau in western China could be gone by 2060, greatly reducing the dry-season flow of the Yellow and Yangtze rivers. The Yangtze is China’s leading source of surface irrigation water, helping to produce half or more of China’s 130-million-tonne rice harvest.

Brown’s report points out that the ongoing shrinkage of underground water supplies and the prospective shrinkage of river water supplies are occurring against the backdrop that by 2050, India will add 490 million people and China 80 million to their billion plus population each.

The major cause of receding glaciers is rising temperatures, caused by atmospheric carbon dioxide concentrations. Brown suggested carbon emissions be cut by 80 percent - not by 2050 as many political leaders suggest, as that would be too late - but by 2020. “The first step is to ban new coal-fired power plants, a move that is fast gaining momentum in the US,” Brown said.

Ironically, the two countries that are planning to build most of the new coal-fired power plants, China and India, are precisely the ones whose food security is threatened by the carbon emitted from burning coal. It is now in their interest, Brown said, to try and save their mountain glaciers by shifting energy investment from coal-fired power plants into energy efficiency and into wind farms, solar thermal power plants, and geothermal power plants.

Glacial lakes in Bhutan, photographed by NASA. Wikimedia Commons