If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.



A Chemical Conspiracy

by Bibiana Campos Seijo
June 29, 2015 | A version of this story appeared in Volume 93, Issue 26

I love a Good conspiracy theory: the Apollo moon landings, the death of Princess Diana, AIDS being a human-made disease—you name it. So I was quite intrigued when, searching “geoengineering” for a project, I came across the ultimate chemical conspiracy theory: chemtrails. This is one I had not heard of before.

Believers in the theory describe chemtrails (quite obviously, a blending of the words chemical and trails) as long-lasting trails left in the sky by high-flying aircraft containing biological or chemical agents that are being deliberately sprayed for sinister purposes undisclosed to the general public. Or as proponent website Global Research describes it, “a 24/7/365 day aerosol assault over our heads made of a toxic brew of poisonous heavy metals, chemicals, and other dangerous ingredients.”

Now, my first reaction is one of disbelief, followed by—as I again go over the words—disappointment that once again we’ve got a bunch of chemophobes here who are happy to lump together “chemicals and other dangerous ingredients.” But why should I expect any different? Paranoia is perhaps more at work here than chemophobia. As I read on, my disappointment turns into frustration.

Chemtrail theory is relatively new—it was first proposed in the 1990s. Activist groups claim that governments and their militaries around the world have been systematically spraying the skies with chemtrails, occasionally referred to as stratospheric aerosol geoengineering, for decades. They speculate that it is part of a clandestine program for solar radiation management or weather modification or—it gets better—psychological manipulation and human population control.

According to believers, chemtrails persist in the atmosphere. The reason for this, they claim, is that planes are fitted with special nozzles that release aerosol lines in a parallel or sometimes in a checkerboard pattern.

Believers maintain that independent tests have shown that chemtrails contain an “extremely poisonous brew” of dangerous compounds such as desiccated blood and mold spores, barium, chromium, nickel, aluminum, and thorium. This of course means that we are deliberately being poisoned on a daily basis, and with such a chemical cocktail around us, it is not surprising that there has been such a dramatic increase in illnesses such as asthma in the past 20 years. That’s some evidence.

Now, debunking this myth is not difficult at all, but as always, one could argue that I’m part of the conspiracy. I’m willing to take that risk. Chemtrails do not exist. EPA, NASA, and NOAA say so. Chemtrails are simply contrails, the result of normal emissions of water vapor from engines at high altitudes in which the water vapor condenses into a visible cloud. This happens when hot, humid air from the engines mixes with the colder surrounding air. The unique characteristics believers attribute to chemtrails, such as the rate at which they dissipate, are entirely dependent on sunlight, temperature, wind shear, and humidity levels, in other words the weather conditions present at the aircraft’s altitude. If the atmosphere is dry, the condensation trail will dissipate quickly; if not, it may exist for some time.

So there is no conspiracy here. It is worth pointing out that contrails consist of not just water vapor but also other by-products of engine exhaust such as carbon dioxide, nitrogen oxides, sulfate particles, and soot. As such, we should be concerned about the release of these gases into the atmosphere and their environmental impact but only as much as we should worry about other exhaust fumes. No sinister purposes. No evil motives.

Views expressed on this page are those of the author and not necessarily those of ACS.


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.