New York Times, March 2021
The idea of artificially cooling the planet to blunt climate change — in effect, blocking sunlight before it can warm the atmosphere — got a boost on Thursday when an influential scientific body urged the United States government to spend at least $100 million to research the technology.
That technology, often called solar geoengineering, entails reflecting more of the sun’s energy back into space through techniques that include injecting aerosols into the atmosphere. In a new report, the National Academies of Sciences, Engineering, and Medicine said that governments urgently need to know whether solar geoengineering could work and what the side effects might be.
“Solar geoengineering is not a substitute for decarbonizing,” said Chris Field, director of the Woods Institute for the Environment at Stanford University and head of the committee that produced the report, referring to the need to emit less carbon dioxide and other greenhouse gases into the atmosphere. Still, he said, technology to reflect sunlight “deserves substantial funding, and it should be researched as rapidly and effectively as possible.”
The report acknowledged the risks that have made geoengineering one of the most contentious issues in climate policy. Those risks include upsetting regional weather patterns in potentially devastating ways, for example by changing the behavior of the monsoon in South Asia; relaxing public pressure to reduce greenhouse gas emissions; and even creating an “unacceptable risk of catastrophically rapid warming” if governments started reflecting sunlight for a period of time, and then later stopped.