Authorities in China might be close to turning to cloud seeding in a bid to clear up the smog problem that's dogging the country.
The website Chinadialogue.net, citing reports from the world's most-populous nation, says the move would be part of a $277 billion government plan aimed at fighting the pollution that's hurting the air quality as China's industrial economy continues to expand.
In cloud seeding, a chemical solution is delivered, often by rockets or aircraft, into the clouds to create ice or water droplets and wring out moisture that will fall to the earth. Scientific American published an interview in 2009 with Arlen Huggins, a researcher in the field, who notes that the process has been studied since the middle of the 20th century and employed for years.
China (and other nations, including the United States) has used weather manipulation techniques in the past. Notably, around the time of the 2008 Beijing Olympics, seeding was used to coax rain showers from the skies and away from the opening ceremony.
Liu Junfeng, a professor at the College of Urban and Environmental Sciences at Peking University, told the site that whether seeding would succeed in China "will depend mainly on the cost and effect of artificial rainfall." If it does lead to precipitation, it might also work toward providing Beijing with a needed boost for its water supplies, he said.
However, odds may be against seeding having a substantial effect on the smog, according to one source Chinadialogue spoke to.
"It is almost impossible to reduce smog and improve air quality by means of using artificial rainfall under the current weather modification technologies," Hong Yanchao, deputy director of the National Consultation and Evaluation Committee for Weather Modification, told Chinadialogue.
New Scientist spoke with Steven Siems, an associate professor at Monash University in Australia, who also expressed doubts about whether seeding would have the intended effect on China's smog. That's because smog already contains dust and soot particles around which ice could form, before leading ultimately to precipitation. If rain isn't being created already by what's in China's air, putting silver iodide in the skies, with the intent of creating new droplets, might not be the solution on a large scale, he says.
- Nature & Environment