In the future, should we try to fight climate change by spraying sulfur dioxide into the upper atmosphere to form a cloud that cools the Earth (a process called geoengineering), ending that plan abruptly could have severe, planet-wide effects on animals and plants, researchers argue in a new paper.
“Imagine large droughts or floods around the world that could be blamed on geoengineering, and demands that it stop. Can we ever risk that?”
“Rapid warming after stopping geoengineering would be a huge threat to the natural environment and biodiversity,” says paper coauthor Alan Robock, a professor in the environmental sciences department at Rutgers University.
“If geoengineering ever stopped abruptly, it would be devastating, so you would have to be sure that it could be stopped gradually, and it is easy to think of scenarios that would prevent that,” Robock says. “Imagine large droughts or floods around the world that could be blamed on geoengineering, and demands that it stop. Can we ever risk that?”
Geoengineering means attempting to control the climate in addition to stopping the burning of fossil fuels, the main cause of global warming, Robock says. While scientists have studied the climate impacts of geoengineering in detail, they know almost nothing about its potential impacts on biodiversity and ecosystems, the study notes.
The geoengineering idea that’s attracted the most attention is to create a sulfuric acid cloud in the upper atmosphere as large volcanic eruptions do, Robock says. The cloud, formed after airplanes spray sulfur dioxide, would reflect solar radiation and cool the planet. But airplanes would have to continuously fly into the upper atmosphere to maintain the cloud because it would last only about a year if spraying stopped, Robock says. He adds that the airplane spraying technology may be developed within a decade or two.