Injecting particles into the atmosphere to cool the planet and counter the warming effects of climate change would do nothing to offset the crop damage from rising global temperatures, according to a new analysis by University of California, Berkeley, researchers.
By analyzing the past effects of Earth-cooling volcanic eruptions, and the response of crops to changes in sunlight, the team concluded that any improvements in yield from cooler temperatures would be negated by lower productivity due to reduced sunlight. The findings have important implications for our understanding of solar geoengineering, one proposed method for helping humanity manage the impacts of global warming.
“Shading the planet keeps things cooler, which helps crops grow better. But plants also need sunlight to grow, so blocking sunlight can affect growth. For agriculture, the unintended impacts of solar geoengineering are equal in magnitude to the benefits,” said lead author Jonathan Proctor, a UC Berkeley doctoral candidate in the Department of Agricultural and Resource Economics. “It’s a bit like performing an experimental surgery; the side-effects of treatment appear to be as bad as the illness.”
“Unknown unknowns make everybody nervous when it comes to global policies, as they should,” said Solomon Hsiang, co-lead author of the study and Chancellor’s Associate Professor of Public Policy at UC Berkeley. “The problem in figuring out the consequences of solar geoengineering is that we can’t do a planetary-scale experiment without actually deploying the technology. The breakthrough here was realizing that we could learn something by studying the effects of giant volcanic eruptions that geoengineering tries to copy.”
Read more at University of California - Berkeley
Image: One proposal for solar geoengineering is to inject sulfate aerosols into the atmosphere, similar to what happens after large volcanic eruptions. The blanket of smog acts as an umbrella, reducing sunlight and temperatures a few percent to counter global warming. (Credit: Stephen McNally and Hulda Nelson, UC Berkeley)