Cloud-Seeding Safe, Chinese Experts Explain

Feb 18, 2011     Email"> PrintText Size

With efforts to manipulate the weather and induce precipitation intensifying because of the drought that has hit much of China, atmospheric experts have been reassuring the public that the release of chemicals into the sky will not hurt the environment.

"The impact of weather manipulation can be ignored because the dose of the catalyst is too small to cause a problem,"Lei Hengchi, a professor specializing in weather intervention at the Institute of Atmospheric Physics under the Chinese Academy of Sciences, was quoted as saying by Thursday's China Daily.

While silver iodide -- the most common catalyst used to encourage clouds to discharge their water -- is considered a hazardous substance and a toxic pollutant, the quantities used are not large enough to have any effect on the environment, he explained.

China has discharged silver iodide, dry ice and liquefied nitrogen into clouds from aircraft or from stations on the ground to enhance precipitation in dry regions since the 1950s.

Dry ice and liquefied nitrogen have absolutely no effect on the environment, People's Daily quoted Wang Guanghe, deputy director of the artificial weather intervention center under the China Meteorological Administration, as saying.

Wang said they turn into carbon dioxide and nitrogen, elements that are ordinarily found in the air. Wang agreed that the quantities of silver iodide being used are too small to have an impact, even thought he said the substance is considered toxic.

Lei added that experiments failed to find any silver iodide in Huairou Reservoir, on the outskirts of Beijing, after silver iodide was dispersed into clouds upstream of it.

Beijing burned more than 2,000 silver iodide rods at weather manipulation stations to enhance recent snowfalls on the city. About 6.5 kilograms of silver iodide in total was involved.

(Source: Xinhua)