As the world faces record temperatures and ongoing issues with drought, scientists look towards solutions for not only saving water, but creating it. We have the science and the capabilities to create rain. So the question is whether cloud seeding is worth the time, money and effort.
What is cloud seeding?
Think of it as planting a garden in the sky. Cloud seeding is not a new idea. Originally developed by Nobel prize-winning chemist Irving Langmuir and his deputy Vincent J. Schaefer in the 1940s, the process involves stimulating the moisture inside clouds to enhance precipitation. It’s done by injecting particles, gasses or chemicals into existing clouds.
Scientists have done this through everything ranging from an airplane spraying the cloud to ground-launched flares aimed to the sky. Although the material and injection methods vary, they all act similarly inside the cloud.
Clouds are full of teeny tiny droplets of moisture that aren’t heavy enough to fall to the ground. When stimulated by the chemicals, most commonly silver iodide, those droplets are able to create an anchor and absorb the surrounding droplets. When they become heavy enough, in as little as 20 to 30 minutes, the drops then fall from the sky as rain or snow. Cloud seeding is credited with causing moisture to fall, either by initiating rain or by increasing the amount of precipitation that falls.
Is cloud seeding being used?
Yes, around the world. Australia, China, India, Israel, South Africa and Thailand all have programs. Over the years, around 50 countries have tried it in some capacity. In the United States: California, Idaho, Nevada, Utah, Colorado, Wyoming, Texas and North Dakota all practice some form of cloud seeding. Because the science relies on the right types of clouds in the right weather conditions, the opportunities to plant the seeds is limited to when storms roll through. That means cloud seeding during the winter in the hopes of improving water conditions for agriculture and other consumption during the summer.
Does cloud seeding work?
It’s a great debate. Some researchers show precipitation increases from 3% to 15%, while other researchers dispute those claims, saying it’s impossible to isolate cloud seeding as the contributing factor. In other words, we just don’t know decisively if it’s helping, but many in the scientific community, as well as agricultural and drought-stricken regions, are optimistic.
What are the advantages of cloud seeding?
The obvious advantage is the production of precipitation. With more research, we can discover whether it’s an effective means of increasing snowpack in the mountains and rainfall in wet regions. Many regions are already labeling their efforts a success, even if other scientists may not definitively agree. For example, organizers of a five-year program in the Snowy Mountains of New South Wales, Australia claim snowfall increased by 14%, while a similar program in Wyoming reported a 15% increase. These figures offer a promising option in battling drought.
What are the disadvantages of cloud seeding?
Using airplanes to deliver the chemicals means adding carbon emissions to the atmosphere while we attempt to battle the water crisis. However, drones are a more environmentally-friendly option, and just as viable. Plus, rockets can be shot from the ground surface without the use of a plane.
However, cloud seeding is not a once-and-done treatment. An unknown in the equation is whether cloud seeding will create an imbalance for nature to figure out. The argument goes that synthetically producing more precipitation than nature intended might keep the environment from balancing naturally.
What’s the future of cloud seeding?
At this point, it’s definitely part of the ongoing conversation. The efforts are spreading across the western U.S. and around the world as it gains traction as a viable contributor in fighting drought conditions. Even proponents don’t pretend cloud seeding is a solution to the world’s drought problems, but it could be part of the answer. The drought issue is huge and will require a robust solution from a combination of angles.
While producing more precipitation is an important aspect, we have to look at the entire water cycle. Remember elementary school science class when we learned the same water continues to cycle from the sky to the ground and back to the sky? That precipitation falls to the Earth, where it is absorbed and stored in the soil. Additional water ends up in the streams, lakes, rivers and oceans. Through evaporation and transpiration that water heads back into the sky where condensation occurs.
However, when temperatures are too hot, the cycle breaks down, leaving the moisture in the sky instead of in the soil and waterways. So in addition to cloud seeding as one piece of the pie, policies and people need to still focus on water conservation. In the end, the answer will be a combination of solutions, at every level of government and across borders.
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