Climate change-induced warming is drying out the American West by not only reducing precipitation, but also by accelerating evaporation — even amid adequate rainfall, a new study has found.
Evaporation accounted for 61 percent of the region’s drought severity from 2020 to 2022, while reduced precipitation was responsible for just 39 percent of these conditions, according to the study, published Wednesday in Science Advances.
Historically, drought in the U.S. West was driven by a lack of rainfall, while evaporative demand — the amount of water that the atmosphere can absorb from the Earth’s surface — has only played a small role, the study authors noted.
But climate change caused by burning fossil fuels has brought about higher average atmospheric temperatures and has increased the contributions of evaporation to drought severity, the researchers explained.