Over 100 people have now been confirmed dead following flash floods in central Texas over the weekend, including 27 young campers and staff at a local girls' summer camp.

Unfortunately, despite meteorological professionals explaining in news outlets all over the world how and why such devastating flooding occurs, parts of social media have become breeding grounds for disinformation.

One popular conspiracy theory, which has been given credence by current and former US political figures—including Republican Congresswoman Marjorie Taylor Greene and former National Security Advisor General Mike Flynn—concerns "cloud seeding" — the practice of chemically inducing rainfall from clouds in areas affected by drought.

DW Fact check takes a look.

Claim: As of Tuesday, over 2.6 million people had viewed a post on X by a well-known conspiracy theorist account which suggested a link between the deadly floods and cloud seeding operations conducted two days earlier by Rainmaker, a weather modification start-up funded partly by US software billionaire Peter Thiel.

In another post, viewed over 2.8 million times, the same account claimed that the state of Texas is "running seven massive cloud seeding programs" in an attempt to "enhance rainfall across millions of acres" and questioning: "Did they push the clouds too far and trigger this flood?"

DW Fact check: False

Accompanying the post was a video originally published on TikTok on May 2 in which the user questioned whether "blue rain" at a camping site in Texas was linked to "chemtrails" or, in the video description, "cloud seading" (sic). The video had been viewed over 3.1 million times by Tuesday.

The claims gained traction among certain right-wing US politicians including Christian nationalist and conspiracy theorist Marjorie Taylor Greene who said in a post on X, viewed over 8.3 million times, that she would be introducing a bill to Congress to "end the dangerous and deadly practice of weather modification and geoengineering."

General Mike Flynn, former National Security Advisor to US President Donald Trump during his first term, further peddled the theory to his 2.1 million followers on X here and here.

Texas floods: what is cloud seeding?

Cloud seeding is a weather modification technique used to induce rainfall.

It involves dispersing insoluble salts such as silver iodide among existing clouds, either via aircraft, drone or shot up from the ground. Water vapor particles in the clouds are thereby "tricked" into forming larger droplets around the silver iodide particles, eventually becoming large and heavy enough to fall as rain.

"Cloud seeding itself cannot create rain out of nothing," adds Edward Gryspeerdt, a Research Fellow at the Department of Physics at Imperial College London (ICL), pointing out to DW: "Cloud seeding aims to identify clouds that are not currently raining, but are very close to doing so."

The first attempts at cloud seeding were made by US scientists at the General Electric Research Laboratory in the 1940s. Today, the method is used in various countries across the world to relieve drought, including in China and the Middle East.

Rainmaker, the company at the center of the Texas flooding claims, is contracted across the western United States by various municipalities and state governments to produce more water in regions impacted by drought, including in California, Arizona, Oklahoma, Colorado and Texas, its CEO Augustus Doricko confirmed on an X Space hosted by a conservative influencer on Monday, July 7.

The most recent operation in the vicinity of Kerr County, where the floods took place, was on July 2 – two days before the floods, hence the speculation that the cloud seeding activity could have exacerbated the heavy rainfall.

Could cloud seeding have contributed to the Texas floods?

"The flooding, unequivocally, had nothing to do with Rainmaker's activities or any weather modification activities," insisted Doricko, 20 minutes into Monday's X Space – a claim backed up by scientific consensus.

"Cloud seeding might be able to modify a cloud that already exists, but a large thunderstorm requires a huge amount of water and energy," explains ICL's Gryspeerdt. "Cloud seeding cannot provide either of these — it only creates small modifications to existing clouds."

Travis Herzog, award-winning chief meteorologist at broadcaster AB13 in Houston, Texas, concurs, stating in a Facebook post on July 6: "Cloud seeding cannot create a storm of this magnitude or size. In fact, cloud seeding cannot even create a single cloud. All it can do is take an existing cloud and enhance the rainfall by up to 20% — and even that is on the high end. It is physically impossible for [cloud seeding] to have created this weather system."

"Cloud seeding played ZERO role in [the] deadly Texas floods – rudimentary, basic physics explains that," agreed Matthew Cappucci, an atmospheric scientist and senior meteorologist at MyRadar, a leading Florida-based weather app.

"In dry environments, adding cloud condensation nuclei can help clouds drop subtly more rain," Cappucci added in one of several posts on the subject on X. "You don't spontaneously make 4 trillion gallons of water appear in Texas."

Texas: Cloud seeding particles would have long since dispersed, say experts

What's more, CEO Doricko claimed, given the almost two-day gap between Rainmaker's last operation over Kerr County, any rain-inducing silver iodide particles dispersed on July 2 would have long since dispersed into entirely inconsequential densities — a statement which is also backed up by scientific consensus.

"The horizontal winds at cloud level would have moved the air volume that was cloud-seeded at least 1,000 kilometers away from the location of the cloud seeding between 2 and 4 July," explained Dr. Sandra Yuter, Distinguished Professor of Atmospheric Sciences at North Carolina State University, speaking to DW.

Dr. Yuter's calculation was based on average horizontal wind dispersal speeds of approximately 10 m/s (36 km/h, 22.3 mph), after consulting nearby weather balloon data from July 3.

Given that the state of Texas is about 1,320 kilometers (820 miles) wide at its broadest point, Dr. Yuter concludes: "Any cloud seeding on July 2 in the vicinity of Kerr County would not have changed the rainfall from the storms that hit the region on July 4."

Climate change: Extreme weather events to become 'more common'

ICL's Edward Gryspeerdt concludes that "the floods in Texas were driven by record amounts of atmospheric moisture over a region that is known for flash floods" and warns that, as the atmosphere warms due to climate change, such extreme rainfall events are likely to become worse:

"Climate models predict that while Texas may become slightly drier on average due to climate change, the intensity of rainfall will likely increase, suggesting that these types of thunderstorms will become more common in the future."

This is not the first time that flash floods have triggered the claim of cloud seeding being the cause for it.