China is now controlling the weather. What’s the environmental cost?

China artificially modified the weather in advance of a political celebration last July, a study by Tsinghua University reveals. The Chinese government used ‘cloud seeding’ to control rain and reduce pollution in Beijing, in preparation for its Communist Party centenary event. Gathering under unusually clear skies, tens of thousands of people attended the ceremony in Tiananmen Square.

Reports by the South China Morning Post confirm that the operation succeeded and the city saw a drop in air pollution. There was a reduction in the level of PM2.5 air pollutants by more than two-thirds - and this shifted the air quality index reading from “moderate” to “good”, under WHO standards.

Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation that falls from clouds. It does this by dispersing chemicals into the air which serve as cloud condensation. When you introduce these substances into the clouds, the water droplets cluster together, increasing the likelihood of rainfall - meaning clouds clear from the sky. Weather manipulation of this type is also known as “blue-skying”.

Read more