In the past few weeks, a video showing an aeroplane leaving behind an impressive trail has garnered several tens of millions of views online. Some people claimed that the video was new proof for the existence of "chemtrails", or chemical trails, a term used by conspiracy theorists who are convinced that various governments are attempting to negatively affect the climate or human health by spreading toxic chemicals. Though this conspiracy theory is around 20 years old, it maintains a massive following.

While flying at a height above 10,000 metres altitude, a Russian pilot filmed a Boeing 787 flying above Russia’s eastern coast on June 17, 2017.

"The sun behind it helps it look more dense as it creates its own shadow,” says one of the comments on the video, which was published on Facebook, explaining why the plume of smoke looks so thick. By mid-September, people were commenting non-stop on the video, which had been shared hundreds of thousands of times.



The video has been picked up by quite a few untrustworthy pages and media sites that claim it shows an example of a "chemtrail". This portmanteau refers to “trails of chemical products” that some people claim are being deliberately spread in the atmosphere by government agencies for a variety of reasons, ranging from poisoning people to changing or controlling the climate, to testing chemical weapons.

A conspiracy theory that started in the United States and has been circulating for years

"This conspiracy theory is old. It first appeared on the web in the United States in the 90s when conspiracy theorists close to the extreme right were convinced that the government was trying to poison them,” says Mick West, the founder of two websites aimed at debunking this kind of video, Contrail Science and MetaBunk.

West says that the conspiracy theory can be mostly traced back to one man, Dane Wigington, who runs the website GeoEngineeringWatch. Wigington noticed that his solar panels weren’t working properly, so he started doing research online. He came to the conclusion that the condensation trails left by planes were obscuring the sky and contained harmful chemicals. Since then, he has been promoting this theory through his website, social media and even on billboards.

This billboard was paid for by adherents to the chemtrails conspiracy theory. (Photo posted in August 2016 on Facebook). 

Proponents of this theory use all sorts of different photos and videos to support their claims. The France 24 Observers team also spoke to a researcher in aerodynamics at Louvain Catholic University in Belgium (who wished to remain anonymous in this article).

Images taken out of context then “explained” using fake technical arguments

Chemical products spilled by accident on the runway?
No, a draining fuel tank


On "The People’s Voice" Facebook page, which styles itself as an alternative media that treats subjects the mainstream media won't, and often shares false information, a video shows liquid flowing from the wing of an airplane parked on an airport runway.

"That’s just fuel spilling out of the tank, either by accident or because it is being drained,” explains the researcher in aerodynamics. 

You can see "chemical products being released” between 1'07 and 1'27 in this video, which you can watch by clicking on the image (or here).

Very often, planes will empty out fuel before a landing as a way to adjust their weight. Numerous “documentaries” (only available on YouTube and using questionable sources) use photos of this process as proof for the existence of “chemtrails”. But dropping fuel is actually a pretty routine part of flights. This process is captured on film in quite a few documentaries on aviation (you can check it out in the 12th minute of this video, for example).

This aeroplane has four motors but six trails… Weird, right? Well, it all comes down to aerodynamics


This footage of an aeroplane shows something odd, which some internet-users believe is proof of a conspiracy going on. Usually, when a plane flies, a trail of condensation (a “contrail”) flows from each engine. However, this four-engine plane has six trails of condensation.

In reality, the trails from each engine sometimes blend and can take different forms depending on the temperature, altitude, gradient and even the standpoint of the viewer. West wrote a blog entry about this aerodynamic phenomenon and posted it on Metabunk if you want to learn more.

Hidden tanks on airplanes? Actually ballast tanks to simulate
the weight of passengers during test flights

If you click on the image or this link, you can see footage showing objects that some claim are tanks of chemical products at 2'53.

In actuality, these barrels are full of water and are used to simulate the weight of passengers during test flights. The photo was actually taken during an aviation trade show in Bourget in June 2011. It shows the interior of a Boeing 747-8JK, which was modified for a test. You can check out more examples on West’s website.

A large amount of products dropped all at once? A Canadair

Between 5'48 and 6'08, you can see the sequence that some claim shows a large amount of chemicals being dropped by a plane. (Watch the video by clicking on the image or on this link). 

This video shows an aeroplane suddenly dropping a large quantity of something white. In reality, the white substance is water being sprayed on a fire. The specific plane shown is a Boeing 747 by the company Evergreen that has been converted into a Canadair, a model of plane created to fight wildfires. (You can see the video in its original context by clicking here.)

Toxic black fumes? Smoke used for an airshow

You can see the black smoke that some claim is “toxic black fumes” In the 10th second of this video (to see the video, click on this link or on the link).

This video, which has been widely circulated by French-speaking chemtrail conspiracy theorists, shows an aeroplane descending over a town. It then appears to release some black smoke for a few seconds.

"The smoke in this video is coming from a smoke grenade, used by small military planes during air shows," West explains.

An unidentified group of planes flying in formation? Just military planes

Screengrab from the Chemtrails Global Skywatch, Facebook group, which gathers hundreds of videos and photos that its administrators claim prove the existence of chemtrails. 

In the Facebook groups where these conspiracy theories circulate, members share hundreds of photos and videos each week showing what looks like grid patterns of contrails criss-crossing in the sky. These conspiracy theorists claim that this is proof that these planes are following some kind of pattern to cover the ground thoroughly.


"There are unidentified planes that spray [chemicals]", claimed one user in a video published online in May 2017. He says that the planes are flying in a strange formation and that they do not appear on Flight Radar, a website that shows the planes present in the sky at any given time.

But "these are actually military planes, which are never identified on Flight Radar for obvious security reasons. They are flying in a chevron formation, which is common within the ranks of the air force,” said our researcher. He also says that there is nothing strange about the condensation trails.

Why has this conspiracy theory caught on?

To understand what is going on in these videos and photos you would need knowledge of aviation, engineering and climatology, to name just a few fields. When you are looking at these photos and videos, it’s pretty easy to come to the wrong conclusion if you don’t have advanced understanding in these domains.

After speaking to several believers in chemtrails, West found a common thread. All of them first started believing in chemtrails after watching a video called “What in the World Are They Spraying?”, which was posted on YouTube in 2010 by an American called Paul Wittenberger. The video is presented as a documentary but was only ever shared on YouTube.

"This film is made up of a web of lies presented as proof, but it is so well done that people are convinced by it,” West says. “After seeing it, they start looking at sites where conspiracy theories are often shared and they start categorically refusing to listen to anyone who questions the theory.”


West says that the one thing that seemed to convince people to stop believing in the chemtrails theory is one of his videos that debunks the theory. This video explains that condensation trails can stay in the air for several hours. Furthermore, he says that this has been the case throughout the history of aviation, thus countering the claims made by the fake documentary.

Everyone knows that planes are polluting; there's no need for a conspiracy theory

Many believers in the chemtrails conspiracy theories start with facts, which they then wrongly interpret or make generalisations from.


In 1996, the US navy published "Weather as a Force Multiplier: Owning the Weather in 2025". This report studies the possibility of modifying the climate for strategic or military aims using, among other methods, chemical drops by planes. This report is one of the first to consider different techniques that could be used by humans to change the climate. Most of these methods have never been used. However, there are various climate-controlling methods that are used on a small scale. For example, cloud-seeding is a technique used to increase rainfall. It’s used to combat drought but remains a controversial method.

Aeroplane engines, aside from leaving a trail of condensation, also emit CO2. In fact, planes are responsible for 3 per cent of CO2 across the globe, and pollute the environment. The small clouds that are sometimes created by these condensation trails, called cirrus clouds, also contribute to global warming. Aeroplanes are far from harmless for both humans and the environment – you don’t need a far-fetched conspiracy theory to believe that.


Article written with
Liselotte Mas

Liselotte Mas