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Climate change threatens food supply of 60 million people in Asia

Date:
June 18, 2010
Source:
Utrecht University
Summary:
Climate change will drastically reduce the discharge of snow and ice meltwater in a region of the Himalayas, threatening the food security of more than 60 million people in Asia in the coming decades, according to new research in Science. The Indus and Brahmaputra basins are expected to be the most adversely affected, while in the Yellow River basin the availability of irrigation water will actually increase.
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aken while facing south on the Tibetan plateau near Tingri, close to the Mount Everest base camp, at an elevation of 4380m above sea level, this photo illustrates the ‘water tower’ function of the Himalayas.
Credit: A. Hamer

According to an article by three Utrecht University researchers published in the journal Science on 11 June, climate change will drastically reduce the discharge of snow and ice meltwater in a region of the Himalayas, threatening the food security of more than 60 million people in Asia in the coming decades. The Indus and Brahmaputra basins are expected to be the most adversely affected, while in the Yellow River basin the availability of irrigation water will actually increase.

More than one billion people depend on the meltwater supplied by the Indus, Ganges, Brahmaputra, Yangtze and Yellow River. The snow and ice reserves situated upstream are important in sustaining the availability of water downstream. Researchers from Utrecht University and FutureWater have calculated the reduction in glacier and snow coverage and forecasted the future river discharge and made predictions about food security in the basins of these five major rivers.

How important is meltwater?

"The role of meltwater in the Indus basin is much more significant than that in other river basins in Asia," according to Walter Immerzeel, hydrologist at Utrecht University and FutureWater. "The downstream sections of the Indus are dry, are home to one of the largest irrigation networks in the world and are completely dependent on meltwater."

Food production

Climate change will ultimately result in declining discharge levels of the major Asian rivers, impacting the volume of irrigation water available. "Our model calculations show that the Brahmaputra and Indus are the most vulnerable. According to our estimates, this will threaten the food security of the approximately 60 million inhabitants of these areas by the year 2050," explains Immerzeel. "However, the opposite is also possible. In the Yellow River basin, an increase in wintertime rainfall is expected, resulting in increased availability of water early in the growing season."

Uncertainty about glaciers

The size and discharge of Himalayan glaciers are experiencing significant decline due to climate change. "However, observed glacial decline varies greatly from region to region, and there is a high degree of uncertainty regarding the speed of decline," says Marc Bierkens, hydrology professor at Utrecht University. "However, the trends identified in the river discharge forecast do not take this uncertainty into account." The researchers based their results on a combination of hydrologic models, climate forecasts from five different climate scenarios, and satellite images depicting snow and ice, rainfall, and changes in the Earth's gravitational field.


Story Source:

The above post is reprinted from materials provided by Utrecht University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Immerzeel et al. Climate Change Will Affect the Asian Water Towers. Science, 2010; 328 (5984): 1382 DOI: 10.1126/science.1183188

Cite This Page:

Utrecht University. "Climate change threatens food supply of 60 million people in Asia." ScienceDaily. ScienceDaily, 18 June 2010. <www.sciencedaily.com/releases/2010/06/100616090225.htm>.
Utrecht University. (2010, June 18). Climate change threatens food supply of 60 million people in Asia. ScienceDaily. Retrieved July 30, 2015 from www.sciencedaily.com/releases/2010/06/100616090225.htm
Utrecht University. "Climate change threatens food supply of 60 million people in Asia." ScienceDaily. www.sciencedaily.com/releases/2010/06/100616090225.htm (accessed July 30, 2015).

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