Chemtrails (Sigh): What People Are Getting Wrong This Week

In this column I try not to cover topics that any normal person already knows are fake. I don’t bother writing about people who think Elvis is alive or that the Earth is flat, because anyone with two brain cells to rub together already knows those are bullshit, and believers are a tiny minority on the fringes of society.

I had considered “chemtrails” in the “no one takes this seriously” column, but I was wrong. This week, legislators in Tennessee passed a state law that bans “the intentional injection, release, or dispersion, by any means, of chemicals … substances, or apparatus … with the express purpose of affecting temperature, weather, or the intensity of the sunlight.” In other words, they banned chemtrails.

While the legislation was drafted partly in response to a Federal government report released last year on solar geoengineering—basically the idea of cooling the planet by reflecting sunlight back into space—some lawmakers didn’t get the memo. Here’s what Tennessee Sen. Frank Niceley said in support of the law: “This will be my wife’s favorite bill of the year. She has worried about this, I bet, 10 years … If you look up—one day, it’ll be clear. The next day they will look like some angels have been playing tic-tac-toe. They’re everywhere. I’ve got pictures on my phone with Xs right over my house. For years they denied they were doing anything.” 

The report that riled up Tennessee legislators explicitly says the research “does not signify any change in policy or activity by the Biden-Harris Administration.” We don’t even know how or if it would work, so solar geoengineering is a non-starter. Chemtrail conspiracy theories are fake and dumb. But Tennessee’s decision to outlaw both could be a great and/or hilarious thing—if they follow the letter of the law they wrote.

What are chemtrails?

Believers call the long, white trails sometimes left in the sky by jet airplanes “chemtrails.” They believe chemtrails are the result of the government intentionally spraying biological or chemical agents into the sky in order to change the weather, control the population, and/or make people sick (the specifics depend on who you ask).

But the trails Sen. Nicely has pictures of on his phone are really called “contrails,” short for condensation trails, and no one is denying anything. Contrails are the result of water vapor released from aircraft engines’ exhaust. They are mostly ice crystals, basically jet-made clouds, and there is no evidence they can control people’s behavior. But they might actually change the weather. (More on that below.)

Contrails are an interesting conspiracy theory element because you can walk outside and see them for yourself; but sometimes you don’t see them, just like the Senator said. So are some aircraft spraying chemicals and others not? According to the authorities, no one is spraying anything. Contrails only form under certain atmospheric conditions, even if it looks like angels have been playing tic-tac-toe.

Is there any evidence that chemtrail conspiracy theories are true?

Chemtrail conspiracy theorists are partly right, but, as is usual with conspiracy theorists, not in the way they think they are. The U.S. government really is trying to control the weather by releasing a chemical into the air from planes. It’s called cloud-seeding, and the chemical, silver iodide, is harmless to humans. The idea is to prevent droughts by making clouds more productive. Cloud-seeding has been around since the 1940s. It’s difficult to say for sure whether it works (it’s hard to get a control group of clouds), but it’s not secret. There are ongoing, relatively small, government funded cloud-seeding programs in several states, including Utah, Wyoming, and Colorado. But not in Tennessee, obviously.

The second part of the chemtrails theory is a little right too. You don’t need to be a conspiracy theorist to accept that the U.S. government has a long, troubling history of secretly dispersing chemical and biological agents in the air over the U.S.; They admit it themselves. But the government (officially) halted biological and chemical weapons programs in the 1960s, and in 2023, the U.S.’s last chemical weapon, a sarin nerve agent-filled M55 rocket rocket, was destroyed, according to the international oversight group The Organisation for the Prohibition of Chemical Weapons.

So weather control programs and secret dispersal of chemicals exist, and the U.S. is looking into solar geoengineering, but nothing connects jet engine vapor-trails to any of these things. That doesn’t mean contrails are benign though; they might even be worse than conspiracy theorists fear.

Are contrails harmful? 

In another “a broken clock is right twice a day” victory for conspiracy theorists, legitimate research indicates that contrails are harmful, maybe extremely harmful, but not because they contain population-control nanobots.

It’s hard to pin down the specific causes of temperature changes in a system as complex as the climate of a planet, but research has long supported the theory that jets creating tiny clouds in the sky prevents heat from escaping the planet, leading many climate scientists to regard contrails as a major contributor to global warming.

Contrails may be worse than the effect of burning all that jet fuel in the first place. According to the Yale School of the Environment, the constant injection of jet-made clouds has a “daily impact on atmospheric temperatures that is greater than that from the accumulated carbon emissions from all aircraft since the Wright Brothers first took to the skies more than a century ago.” To make matters worse, efforts to cut the CO2 emissions by making jet engines more efficient tends to produce more contrails that last longer.

So yes, conspiracy theorists, those streaks in the sky are a serious problem that could be contributing to a lot of people dying in the future. (Don’t worry, we’re using AI to stop it, which should work out great.)

Why Tennessee’s anti-chemtrail law might actually be good (but will probably just be funny)

Tennessee law-makers may have crafted this legislation to thwart a federal program that doesn’t exist and fight a made-up phenomenon, but depending on how it’s interpreted and enforced, this law could be the most consequential piece of environmental protection legislation in U.S. history—or it could be a clear enough lesson in what happens when you let conspiracy theorists pass laws that Tennessee won’t vote for dumb people anymore. (I can dream, right?)

To really ban “chemtrails” you’d have to ban all jet travel over Tennessee, which would lower the total amount of contrail-based warming on earth. But that’s just the beginning. Tennessee outlawed releasing anything that “affects temperature, weather, or the intensity of the sunlight” without defining any of the terms, so it could be read to ban all pollution—from cars, airplanes, factories, or anywhere else—because it contributes to global warming (ie: affects temperature.)

To be fair, the law says the chemicals must be released with “the express purpose of affecting temperature, weather, or the intensity of the sunlight,” so it probably wouldn’t apply to factories, since raising the temperature of the earth is a secondary effect of industry. But sunglass manufacturers could be in the crosshairs. What is a pair of sunglasses if not an apparatus that affects the intensity of sunlight? Maybe sunglasses only affect sunlight’s intensity on a personal level, but the law doesn’t define what “affects the intensity of sunlight” means, so it could be read to cover Ray-Bans and beach umbrellas. You could make a case that the letter of Tennessee’s law bans heaters, air conditioners, stoves, and ovens too, since they are all apparatuses with the express purpose of changing temperature. Water is a chemical, and spraying it onto people at an amusement park is an attempt to change temperature, so goodbye, cooling misters.

I could go on, but it’s all ridiculous. We know that Tennessee is not going to shut down its airports and turn into a post-industrial, sunglass-free state where cooking is outlawed. The law isn’t likely to be enforced in any way, and its only real-world effect will be to make people like Senator Niceley’s wife happy that someone is finally doing something about those pesky angels playing tic-tac-toe in the sky.