Discover the truth behind the conspiracy…

If you look up outside you might notice the blue sky strewn with artificial reflective clouds. These telltale streaks of white are called contrails, and they are produced by aircraft exhaust emissions.
Contrails form when the hydrocarbon content of jet fuel produces water as a by-product of combustion. The water mixes with cold, wet air and condenses, and it can freeze to form ice crystals. However, some believe that there is a more malevolent undercurrent to the goings-on in the upper troposphere and lower stratosphere.

Most advocates of the so-called ‘chemtrails’ conspiracy recall seeing fewer and less lingering contrails when they were younger. However, this can be explained by the dramatic increase in air traffic we’ve seen over the last few decades, as well as cooler exhaust emissions thanks to increased fuel efficiency. Unsurprisingly, the evidence for chemtrails isn’t compelling and remains built on pseudo-scientific principles.

Conspiracy theorists’ claims range from the idea that government agencies are attempting to turn clouds into spying devices to control our minds, to the notion that they are spraying chemicals to deliberately make us sick. There is one peer-reviewed paper on the topic, and it doesn’t support the outlandish secret spraying scandal. The researchers asked 77 atmospheric scientists to review the data for evidence of chemtrails. Only one scientist said there was a possibility some of it could be evidence, but they also articulated that it wouldn’t be the only explanation.

The chemtrail conspiracy theory first emerged shortly after a paper entitled Weather as a Force Multiplier was published by the US Air Force in 1996. The article outlined speculations by military researchers about whether the ability to control the weather could be useful in combat. Though the US Air Force have maintained that this was purely hypothetical, it is understandably a chilling thought. Even so, there’s nothing up in the air with this one: the scientific data confirms that contrails are completely harmless.

This article was originally published in How It Works issue 108 written by Charlie Evans 

For more science and technology articles, pick up the latest copy of How It Works from all good retailers or from our website now. If you have a tablet or smartphone, you can also download the digital version onto your iOS or Android device. To make sure you never miss an issue of How It Works magazine, subscribe today!