The Next Time You’re Out West You Might See Clouds on Steroids

Daniel Modlin

April 4, 2021 at 3:56 a.m.·6 min read

The next time you go to the western United States and look up at the sky, you might see a plane hurling itself into a giant mass of clouds. It might seem unusual, but it is in fact our latest way to combat the effects of climate change.

From the pioneers to Silicon Valley, the history of the West is tied to an innovative, manifest spirit. The landscapes lend themselves to these ideas as well—the jagged Rockies and the adjacent stretches of arid deserts are some of the harshest environments in our country, yet also some of the most biologically diverse and full of life.

If I’m beginning to sound a bit like David Attenborough, there's a good reason. The world as we know it is changing—and we are, in what should come as a surprise to no one, at the very center of it.

Among these intrepid and dramatic locales is where one of mankind’s greatest experiments is taking place and where an important question is being asked: Can we adjust the weather to better suit us?

Scientists say, well, sort of.

The idea of cloud seeding and weather modification has been around since 1940.

There were federally funded programs in the 1960s—one named Project Skywater that ultimately had mixed results. In the 1970s and 1980s, the US government began experimenting on how weather modification could be used as a war tool. But outside of ski resorts like Vail, where the technology is used to help increase snow during snowstorms, interest in cloud seeding largely dropped off.

Frank McDonaugh, the Associate Research Scientist of Atmospheric Science at the Desert Research Institute, argues this was likely an overselling of the efficacy of cloud seeding: “People were saying they could double the amount of precipitation, which just wasn’t true.”

However, over the last few years, there has been a surge in interest in geoengineering and weather modification as a tool to combat, or at the very least, mitigate the immediate effects of climate change. This experimentation is prevalent in eight states within the American Southwest, all of which are currently experiencing one of the driest periods ever recorded, and have never been more desperate for rainfall.

For Utah and Nevada, 2020 was the driest year on record, and for Colorado, it was among the driest, too. In fact, the past 20 years have been the driest and most arid span the region has experienced since at least the 1500s according to scientists, and has thus earned the current climate the title of “megadrought.”

As a result of such little precipitation and such extreme temperatures, Utah Gov. Spencer Cox declared a state of emergency last month, and for the first time ever, water officials in the Upper Colorado River Basin states of Wyoming, Colorado, New Mexico, and Utah initiated a drought contingency plan.

The aforementioned plan is three pronged, comprising two reactive solutions: sending more water to smaller reservoirs; and paying farmers to voluntarily stop irrigating during dry years, and one proactive (or at least, it appears to be): increased cloud seeding.

“The idea behind cloud seeding,” Bart Geerts, Professor and Head of the Department of Atmospheric Science at the University of Wyoming, told The Daily Beast, “is to answer the question of whether or not you can make the hydrological cycle more efficient.”

McDonaugh helped to explain the inefficiencies: “Basically only 30 percent of moisture converts into clouds, and then a very efficient cloud on its own will convert 10-20 percent of its moisture to precipitation.”

Cloud seeding aims to extract more of the moisture from clouds by increasing the probability of rainfall.

The way it works is surprisingly simple. Either via an aircraft or via generators on the ground, scientists disperse silver iodide through a small propane flame, injecting the clouds with these silver iodide particles. The water droplets within the clouds then cluster around the particles, modifying the structure of the clouds and increasing the chance of precipitation.

“The answer it turns out, is yes, you can make the hydrological cycle more efficient, but by how much? Well, that’s unclear.” Geerts said.

Geerts pointed to the difficulty of running experiments, as well as the difficulty of knowing how much of the precipitation was a direct result of the seeding. The current estimate, derived from statistical models, is that cloud seeding can yield anywhere from 5-15 percent more moisture from clouds.

If you’re wondering if burning silver iodide in a flame in the sky is environmentally friendly, you’ll be surprised to learn that this isn’t scientists main concern with cloud seeding. Silver iodide is a white, yellowish powder that turns increasingly yellow as it is exposed to sunlight, that was used widely in photography. While it can be toxic if ingested in large amounts (and can even turn your skin a different color), iodine is a naturally occurring mineral that is a critical building block in animal hormones. Furthermore, McDonaugh and Geerts argue that actually, after 50 years of using it in cloud seeding, only a trace amount of silver iodide can be found in snowfall, and it remains stable throughout the process.

In fact, McDonaugh said that cloud seeding could even be construed as a way to ameliorate our pollutant-filled past, and could be edging us towards something of an equilibrium. “We know that pollution makes these clouds less efficient,” McDonaugh said, “so perhaps seeding is putting it back to where it would have been.”

Despite this hopeful outlook, scientists like Geerts and McDonaugh stressed that this isn’t a “silver bullet” for solving climate change or really even mitigating droughts already underway.

“Part of the problem is you can’t make something out of nothing,” Geerts said, referring to the fact that you can’t seed clouds if there are none in the sky. Geerts mentioned it really does nothing to address the underlying issue or cause of the megadrought, which is at its core, climate change.

Geerts’ colleague, Katja Friedrich, an Associate Professor of Atmospheric and Oceanic Sciences at the University of Colorado Boulder, argued a similar thing. Friedrich wondered about the feasibility of cloud seeding in the next 5 to 15 years. “Cloud seeding works well in a very narrow temperature range, so the problem is, if the atmosphere gets warmer, then we will have less chances to cloud seed,” she told The Daily Beast.

According to the North American Weather Modification Council, there are currently several projects being run in California, Wyoming, Colorado, Texas, Utah, among other states with a project here or there. While there are none occurring in Arizona and New Mexico, these lower basin states do contribute to the funding of other states’ projects.

In regards to states continuing to run cloud seeding programs, Friedrich said it comes down to two fundamental questions: “How desperate are we? And how much are we willing to pay for water?”

“Right now,” she said, “every drop counts.”