August 31, 2009
Air pollution in eastern China over the past half century has reduced rainfall and increased the risk of drought and crop failures, reports a study published in the Journal of Geophysical Research.
Deliang Chen of the University of Gothenburg in Sweden and colleagues found that aerosols generated by air pollution has reduced the size of raindrops, making it "more difficult for smaller raindrops to coalesce into rain clouds that can release rain," according to a statement from the university. The researchers note that the number of rainy days in parts of eastern China has fallen by 23 percent over the past 50 years while aerosol emissions have increased by 800 percent.
"The consequences are increased drought and poorer harvests," the university statement said.
Research in other parts of the world, including the United States, the Amazon rainforest, and Borneo, have also shown that aerosols from pollution and forest fires can reduce rainfall.