Geoengineering might work best in small doses

A study suggests solar geoengineering could work most effectively by trying to blunt half of expected global warming, rather than all of it.

Why it matters: Government policies to cut carbon emissions aren't on target to keep warming below dangerous levels, so geoengineering may eventually be necessary. By aiming for a more modest offset of the warming to come, researchers may be able to maximize the benefits while minimizing the risks.

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How it works: Solar geoengineering involves trying to directly cool the climate by injecting aerosols into the atmosphere, which would reflect incoming sunlight.

Details: The new study, published in Environmental Research Letters, used computer models to conclude that putting enough aerosols into the stratosphere to cut expected warming in half appeared to hit the sweet spot of slowing climate change without inadvertently making it worse in some regions.

"When used at the right dose and alongside reductions in greenhouse gas emissions, stratospheric aerosol geoengineering could be useful for managing the impacts of climate change."

Peter Irvine, University College London, lead author

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