If global warming gases build up so much that record-setting rains, droughts and coastal floods routinely bankrupt businesses and cities, the world’s economic and political powers may decide to aggressively re-engineer the global climate. One option is to fill the atmosphere with enough sunlight-reflecting particles to restore surface temperatures to pre-industrial levels. If they do, would all be cool?
Absolutely not, according to a new study that asked the question to 12 models forced to simulate the global climate with four times more carbon dioxide in the atmosphere than existed in 1850, the start of the industrial revolution. Under such conditions, reflecting sunlight in order to lower temperatures to pre-industrial levels would cause monsoonal rains to drop 5 to 7 percent below pre-industrial levels.