A smog-sucking vacuum is one idea that makes a lot of sense in the attempt to reduce pollution across China; the destruction of outdoor barbecues is one that does not. Artificial rain, otherwise know as cloud seeding, is another measure that was recently given the go-ahead by the China Meteorological Administration. The move is part of a $277 billion anti-pollution investment plan that will go live in 2015 (according to leaked documents). While its effectiveness is still not clear, the hope is that cloud seeding will clear the accumulated smog currently plaguing cities across China.
The technique the Chinese want to use involves firing rockets carrying a payload of silver iodide particles into the clouds. Ice crystals would then form from super-cooled liquid water in the clouds, which would fall as rain or snow depending on the temperature below. The idea is that the artificial precipitation should clear the smog below. However, smog is made of particulates of soot and dust, which should already have acted as ice nuclei. If it hasn’t rained already, then adding more particulates of silver iodide won’t help.
What’s more, satellite data suggests China doesn’t have the right atmospheric conditions for cloud seeding, and Steven Siems, from Monash University in Melbourne, Australia, confirms. He also reinforces the earlier point, which is that the skies over China already contain a lot of ice nuclei from factory pollution and dust from the Gobi desert.
Though taking action such as this is a step in the right direction—also providing some added comfort for residents across China—it won’t be long before new methods need to be explored. There is also the fact that artificial rain would only clear away the existing pollution, as opposed to dealing with the root cause.