The debate focused on the easiest, fastest and cheapest geoengineering option on the table: solar radiation management. This technique would involve intentionally injecting sulfate aerosols into Earth’s upper atmosphere, the stratosphere. These aerosols, which are the same particles released by volcanic eruptions, would reflect sunlight away from Earth, cool the planet, and, in theory, stabilize climate.
While climate modeling shows that solar radiation management would reduce risks for some people, there are a number of reasons why this technique might be a bad idea, Robock said. For instance, pumping particles into the stratosphere could shift rainfall patterns and chew up the ozone layer, thus tinkering with the amount of water and UV light reaching human and ecological systems. “We are going to put the entire fate of the only planet we know that can sustain life on this one technical intervention that may go wrong?” he challenged.