Planet Earth is becoming hazier and the wide blue yonder is increasingly being blotted out by clouds. The problem is not just aesthetic. Low cloud and layers of dust and pollution spreading across the northern hemisphere are blotting out the sun. They block out heat so effectively that global warming has been put into reverse in many of the world's most populous countries, according to new calculations about to be published.
Climatologists who spent the past decade warning about global warming are fast reaching the conclusion that cooling poses just as big a threat. But it will not simply cancel out warming. Instead, they see the atmosphere simultaneously being pulled in two different directions by powerful changes to its basic physics and chemistry. It is likely to show increasing signs of stress and unpredictability as a result.
The culprits in global cooling range from the operators of power stations in ...
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