When Florida Gov. Ron DeSantis recently said he'd sign into law a ban on "weather modification activities"—such as spreading tiny particles into the air from aircraft to control sunlight—it raised long-standing controversies over "geoengineering" and "chemtrails."

"I think it's kind of caricatured as kind of kooky," DeSantis said during a May 6 news conference in Miami. "But if you look, there are movements, private businesses, and their view is: We can save you from global warming by injecting different things in the atmosphere, blocking the sun and doing all this stuff.

"And that is something that we're not going to do in Florida. … We're the Sunshine State. We want to have the nice sunshine."

The coming ban on weather modification may have good intentions, weather experts said this week, but it conflates legitimate geoengineering research with conspiracy theories about chemtrails—an unsubstantiated belief that chemicals spewed into the air, and even the familiar white streaks or contrails airplanes leave behind in the sky, could dangerously alter the weather and rain down toxic chemicals on an unsuspecting public.

Plus, these experts wonder if a ban is even necessary.

"I'm not aware of anything going on in Florida and I can't think of any programs," Michael Splitt, an assistant professor of meteorology in the College of Aeronautics at the Florida Institute of Technology, said about geoengineering.

"I just don't understand the priority," Splitt said about the legislation. "People are worried about chemtrails. But polluted cities have a lot of particles already in the air. You drive in city traffic and you breathe in the exhaust fumes."

Geoengineering—also known as climate engineering—refers to large-scale efforts to combat climate change.

That includes proposals to "suck carbon dioxide" out of the sky so the atmosphere will trap less heat or to fire small reflective aluminum particles into the air to act as mirrors and deflect the sun's rays away from Earth, according to a 2019 report by the Massachusetts Institute of Technology.

The bill sponsored by state Sen. Ileana Garcia, R-Miami, would prohibit "the injection, release, or dispersion by any means of a chemical, chemical compound, substance, or an apparatus into the atmosphere" to affect the climate or sunlight. Anyone found guilty of the felony could face fines of up to $100,000 with all funds collected used for air pollution control.

The bill also would require the Florida Department of Environmental Protection to set up a hotline for anyone to report chemtrails or geoengineering efforts.

Tennessee passed a similar law last year and other Republican-controlled legislatures—including Kentucky, Arizona and Iowa—have introduced bills to halt geoengineering and chemtrails.

Initially discovered during the first high-altitude flights in the 1920s, contrails are created when hot air from a plane's engines condenses into ice crystals in the cold air. Their appearance and length of time in the sky depends on the temperature, humidity, wind speed and altitude, according to the National Weather Service. Some contrails last long enough for other planes to fly by creating crisscrossing lines.

Garcia, who joined DeSantis at the press conference, suggested people are frightened by them.

"Many complain constantly about 'Oh what's this Etch A Sketch in the sky? What is it that's going on above and beyond the clouds?'" she said.

But the deeper concern goes beyond ice crystals, to the notion that government agencies are trying to poison the populace or affect weather patterns through geoengineering. Those people include U.S. Rep. Marjorie Taylor Greene, R-Georgia, who on Oct. 3 posted on X: "Yes they can control the weather.

It's ridiculous for anyone to lie and say it can't be done."

A report titled "Fact check: Debunking weather modification claims" released later that month by the National Oceanic and Atmospheric Administration rebutted such claims, stating that solar radiation modification methods have never moved beyond the research stage. So far, it's nothing more than scientists and researchers running computer simulations.

Still, some think the research should go no further. Mark Jacobson, director of atmosphere and energy program at Stanford University in California who holds a doctorate degree in atmospheric science, called geoengineering efforts to redirect sunlight "a hare-brained scheme" that can have drastic effects if they were implemented.

"It's a horrible idea," Jacobson said this week. "These particles will have unintended consequences by reducing sunlight and you are reducing photosynthesis that could lead to the loss of crops and mass starvation.

"And it doesn't reduce one bit of greenhouse gas emissions … It's a waste of time and money. So, in that sense, I agree with the legislation."

But Garcia's bill "distracts people from actually solving the problem of climate change," Jacobson said. Instead, efforts should be made to reduce greenhouse gas emissions on Earth rather than in the skies, he said.

Garcia stands by her bill, which awaits DeSantis' signature after it passed the House 82-28 and the Senate 28-9.

"We have a right to know what is being introduced into our atmosphere, and what the potential ramifications are," Garcia said during the Miami news conference which was attended by bill supporter Marla Maples, President Donald Trump's second wife. They divorced in 1999.