As concerns of water scarcity in the wild west of the United States grow, scientists continue to resort to modern weather modification techniques to create rain in areas of the West Coast facing the worst drought in centuries. With limited rainfall and continuing droughts, the Colorado River and its water-banks are running dry, risking the water supply to over 30 million Americans.
To overcome the drought, in the snowcapped mountains of the West Coast, crushed particles of a chemical compound are being launched from the ground up into the sky or being directly injected into the clouds through airplane flares. The purpose of injecting these particles in the clouds is simple: encourage precipitation, in common terms, provoke rainfall.
While the idea of a cloud making machine may sound as if it’s out of a comic, this process is called cloud seeding, and it is very real. The technique uses particles of silver iodide injected in the clouds. The structure of silver iodide is very similar to ice and thus attracts droplets causing them to cluster and freeze eventually resulting in rainfall/snow. The snow melts during the warmer months and the water is added to the running streams increasing the supply to the population.
The concept of cloud seeding has been around for over 5 decades. It has been used not only to encourage rainfall, but to also reduce hailstone size and to cause clouds to precipitate earlier than when they are expected to.
The effectiveness of the process is still a point of huge discussion as most of the experiments done in the second half of the 20th century didn’t yield satisfactory results and no significant increase in precipitation was ever recorded. However, scientists working on the cloud seeding project believe that right now is the best time to address the issue as global temperatures continue to rise, posing an even greater risk of drought that could last for decades.
Scientists believe that in order to better manage the water supply across America, authorities have only two choices. The first is to reduce the demand by introducing conservation and recycling methods and the second is to somehow increase the water supply. “Cloud seeding is a relatively inexpensive proposition,” remarked Jeff French, an atmospheric scientist at the University of Wyoming.
While Jeff French himself is doubtful about cloud seeding being a viable option to increase rain/snow in the regions, it is a technique worth trying to help regions prone to drought.
Research recently suggested a 5 – 15% increase in rain/snow fell in regions where the technique was implemented, but unfortunately, scientists haven’t been able to draw a concrete link between increased rain and cloud seeding.