This story was originally published by Yale Environment 360 and is reproduced here as part of the Climate Desk collaboration.
Not since Charlemagne was crowned Holy Roman Emperor in 800 A.D. has the American West been so dry. A recent study in Nature Climate Change found the period 2000 to 2021 was the driest 22 years in more than a millennium, attributing a fifth of that anomaly to human-caused climate change. The megadrought has meant more fires, reduced agricultural productivity, and reduced hydropower generation. Last summer, the United States’ two largest reservoirs — Lake Mead and Lake Powell — reached their lowest levels ever, triggering unprecedented cuts in water allocations to Arizona, Nevada, and Mexico.
Desperate for water, several Western states have expanded decades-old programs to increase precipitation through cloud seeding, a method of weather modification that entails releasing silver iodide particles or other aerosols into clouds to spur rain or snowfall. Within the past two years, Idaho, Utah, Colorado, Wyoming, and California have expanded cloud seeding operations, with seeding a key plank in the Colorado Ri... Read more