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On Wednesday, a nonprofit organization called SilverLining announced $3 million in research grants to Cornell University, the University of Washington, Rutgers University, the National Center for Atmospheric Research and others. The work will focus on practical questions, such as how high in the atmosphere to inject sunlight-reflecting aerosols, how to shoot the right size particles into clouds to make them brighter, and the effect on the world’s food supply
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growing body of work already underway. In December, Congress gave the National Oceanic and Atmospheric Administration $4 million to research the technology. NOAA will also start gathering data that will let it detect whether other countries start using geoengineering secretly. And Australia is funding experiments to determine whether and how the technology can save the Great Barrier Reef.
“Decarbonizing is necessary but going to take 20 years or more,” Chris Sacca, co-founder of Lowercarbon Capital, an investment group that is one of SilverLining’s funders, said in a statement. “If we don’t explore climate interventions like sunlight reflection now, we are surrendering countless lives, species, and ecosystems to heat.”
One way to cool the earth is by injecting aerosols into the upper layer of the atmosphere, where those particles reflect sunlight away from the earth. That process works, according to Douglas MacMartin, a researcher in mechanical and aerospace engineering at Cornell University whose team received funding. “We know with 100 percent certainty that we can cool the planet,” Dr. MacMartin said in an interview.
What’s still unclear, he added, is what happens next.
Temperature, Dr. MacMartin said, is a proxy for a lot of climate effects. “What does it do to the strength of hurricanes? What does it do to agriculture yields? What does it do to the risk of forest fires?”
To help answer those questions, Dr. MacMartin will model the specific weather effects of injecting aerosols into the atmosphere above different parts of the globe, and also at different altitudes. “Depending on where you put it, you will have different effects on the monsoon in Asia,” he said. “You will have different effects on Arctic sea ice.”
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Injecting aerosol into the stratosphere isn’t the only way to bounce more of the sun’s rays back into space. The Australian government is funding research into what’s called “marine cloud brightening,” which is meant to make clouds more reflective by spraying saltwater into the air. The goal is to get salt particles to act as nuclei in those clouds, encouraging the formation of many small water droplets, which will increase the brightness of the clouds.
Australian researchers say they hope the technique can save the Great Barrier Reef.