The idea of modifying Earth’s atmosphere to cool the planet, once seen as too risky to seriously consider, is attracting new money and attention.

Excerpt from The New York Times, by Christopher Flavelle:

As the effects of climate change become more devastating, prominent research institutions and government agencies are focusing new money and attention on an idea once dismissed as science fiction: Artificially cooling the planet, in the hopes of buying humanity more time to cut greenhouse gas emissions.

That strategy, called solar climate intervention or solar geoengineering, entails reflecting more of the sun’s energy back into space — abruptly reducing global temperatures in a way that mimics the effects of ash clouds spewed by volcanic eruptions. The idea has been derided as a dangerous and illusory fix, one that would encourage people to keep burning fossil fuels while exposing the planet to unexpected and potentially menacing side effects.

But as global warming continues, producing more destructive hurricanes, wildfires, floods and other disasters, some researchers and policy experts say that concerns about geoengineering should be outweighed by the imperative to better understand it, in case the consequences of climate change become so dire that the world can’t wait for better solutions.

“We’re facing an existential threat, and we need to look at all the options,” said Michael Gerrard, director of the Sabin Center for Climate Change Law at the Columbia Law School and editor of a book on the technology and its legal implications. “I liken geoengineering to chemotherapy for the planet: If all else is failing, you try it.”

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The University of Washington is working on marine cloud brightening and was another recipient of a SilverLining grant. Sarah Doherty, program manager for the university’s Marine Cloud Brightening project, said the challenge would be building spray nozzles that consistently produce the right size particles. between 30 and 100 nanometers, and finding ways to prevent them from sticking together.

The project aims to understand how the clouds respond, and also predict the regional and global climate response. Dr. Doherty said her team hoped to field-test the spray system in the next 12 to 18 months.

“The whole idea of the research we’re doing,” she said, “is to make sure you don’t go out and inadvertently change things in a way that’s going to cause damage.”