Pollution Reduces China’s Rainfall

Pollution is causing rainfall to decrease in certain parts of China.  A little noticed study published in Science earlier this year, somewhat opaquely entitled “Inverse Relations between Amounts of Air Pollution and Orographic Precipitation,” found that average precipitation in a particular mountain region in central China had fallen by 20 percent over the past 50 years.  The authors of the study showed that increasing concentrations of fine, airborne pollutants were responsible for decreasing average precipitation in mountain regions.  

“These findings highlight the threat to vital water resources in polluted regions of the world where hilly-area precipitation makes a significant contribution to the regional water supply, as in the southwestern U.S. central and northern China, and the Middle East.”

Figure:  Trends of annual precipitation amounts and Ro between Mt. Hua and the plain stations of (A) Xi'an and (B) Huayin. 

In past years, the conventional wisdom was that environmental protection, while desirable, was a luxury that a still developing China could not always afford.  This study is part of the increasingly overwhelming body of evidence that environmental pollution actually hurts China’s economic development.  Development that harms a region’s ability to renew its own water supply is not sustainable development.  Many terrific experts within China have been pounding this drum in recent years.

The BBC ran an article on this a few months ago.