Why cloud seeding cannot make or control the weather

Meteorology may have come a long way since its inception, but it is not possible for anyone — whether it be the government, scientists or billionaires — to control the weather, according to experts.
The desert region of Dubai received a record-breaking amount of rain — two year’s worth in 24 hours — in April. Ever since, every time a flash flooding event occurs, ABC New Chief Meteorologist and Managing Editor of the ABC News Climate Unit Ginger Zee has been receiving messages on social media from people who claim the sharp increase in precipitation is not the result of nature.
“They are making it rain” is the overall theme of the conspiracy theories Zee keeps hearing about.
The commenters are often referring to cloud seeding, a weather modification technique currently used in the United Arab Emirates and several places in the U.S., mostly in the Western U.S., a region notorious for its pervasive droughts. The geoengineering technology involves injecting microscopic particles — sometimes silver iodide — into the atmosphere to encourage rain and snowfall.
The particles then act like magnets for water droplets and bind together until they are heavy enough to fall as rain or snow, amplifying the amount of precipitation. But the water droplets can’t be made out of nothing — it has to be already raining or snowing for cloud seeding to take effect.
For the last several decades, there have been investments in small-scale cloud seeding operations in pockets in the West, both ground-based and in the air, Brad Udall, senior water and climate research scientist at Colorado State University, told ABC News.
Despite feats in geoengineering, humans have no capability whatsoever to control the weather, Andrew Dessler, director of the Texas Center for Climate Studies, told ABC News.
“Until recently, we weren’t even sure it worked,” Udall said. “But there’s some new science that suggests, yes, you can slightly increase the precipitation out of storms due to these, usually ground-based, but sometimes air-based efforts.”
Cloud seeding can increase seasonal precipitation by about 10%, according to the Desert Research Institute (DRI).
A 10-year cloud seeding experiment in the Snowy Range and Sierra Madre Range in Wyoming resulted in 5% to 15% increases in snow pack from winter storms, according to a 2015 report from the Wyoming Water Development Office. In the region around Reno, Nevada, cloud seeding is estimated to add enough water to supply about 400,000 households annually, according to the DRI.
While humans can enhance existing weather, it is not possible to control it, Dessler said.
“We humans are not powerless,” Udall said. “But, unfortunately, in the weather realm, our ability to affect things is pretty minor.”
Cloud seeding can’t make it rain. It can’t even make a cloud, according to Zee. And it certainly is not being used to create storms with enough precipitation to cause flash flooding.
If humans could control the weather, then the megadrought in the West would probably never had persisted at the level that it did for decades, Udall said.
In late September and early October, Google searches for cloud seeding ramped up again as Hurricanes Helene and Milton caused severe destruction far beyond the storm’s direct impact, including flash flooding in the mountain region near Asheville, North Carolina, previously considered a climate haven.
While there is some evidence that cloud seeding can enhance precipitation, it’s impossible for humans to create or steer a hurricane, Dessler said.
“It’s amazing we’re even having this discussion because, of course, humans can’t control the weather in ways to create a hurricane,” Udall said.
However, there has been a larger-scale climate modification that has been ongoing for the past two centuries, Zee said.
“We’re doing that right now with green with enormous greenhouse gas emissions on a scale that humanity has never, ever done before,” Udall said.
Since the Industrial Revolution began in the late 1800s, the greenhouse gases emitted from the extraction and burning of fossil fuels have been causing global temperatures to rise at unprecedented rates, according to climate scientists.
The amplification of Earth’s natural warming has actually increased hourly rainfall rates — a key factor in flash flooding — across much of the U.S. by 10% to 40%, according to Climate Central.
“We have all contributed to making it rain more and heavier as we warm the planet,” Zee said.
Dessler likened global warming to “steroids” for extreme weather events.
“Steroids don’t hit a home run, but if you give steroids to a baseball player, he’s gonna hit more home runs,” Dessler said. “And that’s essentially, you know, the way to think about humans and the weather.”
The experts urged people to not believe rumors on the possibility that the weather can be controlled, chalking up the conspiracy theories as machinations of intrigue but nothing more.
“It’s yet one more example, right, of unbridled social media doing irreparable social harm,” Udall said.
ABC News’ Daniel Manzo contributed to this report.