"Dirty Air Fosters Precipitation Extremes"

"Even clouds can suffer from inhaling air pollution, a new study finds, resulting in extreme rainfall patterns that appear to be altering climate across the globe."

"Farmers, municipal water authorities and others who depend on rainfall prefer moderate, dependable precipitation. But as soot and other minute airborne particles — a class of pollutants known as aerosols — get sucked into clouds, the pollution can dramatically alter when clouds deposit rain. The discovery emerged from analyzing every one of thousands of clouds passing over federal monitoring instruments at a site in the western United States over a 10-year period, explains Zhanqing Li of the University of Maryland in College Park.

“Haze, storms, drought and flood: We found very strong evidence that they are well connected,” he said in Washington, D.C., on November 10 at the Symposium on Stratospheric Ozone and Climate Change. He and colleagues published the findings online November 13 in Nature Geoscience."

Janet Raloff reports for Science News November 13, 2011.

Source: Science News, 11/15/2011