At the Rockefeller Foundation in New York, a group of the world’s top climate experts last week give oxygen to a proposal that has long been seen as taboo: injecting more pollution into the stratosphere.
Not just any pollution, but sulphur dioxide, which in large quantities can block enough of the sun’s rays to temporarily cool the planet. The notion of so-called solar radiation modification (SRM), the blanket term for techniques that seek to lessen the power of the sun’s rays, is not new. About 2,000 research papers have been produced on how we can block the sun — from giant mirrors in space to marine cloud brightening, which involves seeding clouds with seawater to make them more reflective.
So far, such ideas have largely
