Reflecting sun’s rays may be way to fight climate change
WASHINGTON — The idea of artificially cooling the planet to blunt climate change — in effect, blocking sunlight before it can warm the atmosphere — got a boost 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.
But the authors argue that greenhouse gas emissions are not falling quickly enough to avoid dangerous levels of global warming, which means the world must begin to examine other options. Evidence for or against solar geoengineering, they found, “could have profound value” in guiding decisions about whether to deploy it.
That includes evidence about what the authors called the social risks: For example, if research showed that the side effects would be concentrated in poorer nations, Field said, it could be grounds not to pursue the technology, even if it benefited the world as a whole.
The report also argued that by publicly funding geoengineering research, the United States could ensure that the work is transparent and accountable to the public, with clear rules about when and how to test the technology.
Some critics said those safeguards weren’t enough.
Jennie Stephens, director of the School of Public Policy and Urban Affairs at Northeastern University, said that geoengineering research takes money and attention from the core problem, which is cutting emissions and helping vulnerable communities cope with the climate disruptions that are already happening.
“We need to double down on bigger transformative changes,” Stephens said. “That’s where the investment needs to be.”