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The idea behind geoengineering is to combat man-made climate change with man-made solutions, mostly involving ways to pull carbon out of the atmosphere or to deflect the sun’s rays so the carbon dioxide has less heat to trap. The ideas are largely untested and highly controversial. They also involve tackling major technological challenges, some of which may be too great to overcome.
“There’s no point in pretending that it’s the technology that is going to save the world when it might turn out to be completely impossible,” said Hugh Hunt, a senior lecturer at Cambridge University who researches geoengineering.
