Study: Cloud seeding really does work
By Matt Weiser, Water Deeply
Cloud seeding has become big business worldwide as a means to boost water supplies. Utilities and governments spend tens of millions of dollars on the process, which is especially common in Western states that rely on winter snowpack to meet year-round water demand.
The basic process involves spraying silver iodide from a plane as it flies through storm clouds. The silver iodide induces moisture in the cloud to form ice crystals, which then (hopefully) fall out as snow.
Some studies have estimated cloud seeding can boost snowfall by between 8 and 15 percent. This figure was derived by comparing snow depth on mountains beneath clouds that were seeded, compared to nearby mountains in unseeded areas affected by the same storm. And it was deduced that seeding made the difference.