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Everyday science

'Chemtrails' are a con, say experts

19 Aug 2016 Hamish Johnston

By Hamish Johnston

Is there a government-led conspiracy that uses aeroplanes to lace the atmosphere with chemicals? Of course there isn’t, and now there is a peer-reviewed study that says so.

Dubbed the “secret large-scale atmospheric programme” (SLAP), the conspiracy concerns condensation trails (contrails) that can often be seen high up in the sky. These are the lines of cloud that are formed when water condensates around particulate matter in the exhaust from jet engines. But are those contrails actually “chemtrails” that are spreading noxious substances far and wide?

Well, that’s exactly what a disappointingly high percentage of people in the US, UK and Canada believe. Indeed, 17% of 3015 people who were questioned about contrails in 2011 said it was true or partly true that there is a secret government programme that uses aeroplanes to put harmful chemicals into the air.

If you want to learn more, type “chemtrails” into a search engine and prepare to be amazed at claims that contrails are related to the testing of biological weapons, a geoenginering effort to mitigate global warming or even a population-control programme.

Now, the first scientific and peer-reviewed study of chemtrail claims has been published in Environmental Research Letters (conspiracy theorists will no doubt point out that this journal is published by the same publisher that brings you physicsworld.com). Not surprisingly, the study finds little evidence that chemtrails exist, as Liz Kalaugher explains in a news article on environmentalresearchweb: “Are chemtrails a con?“.

Sadly, I don’t think this will convince many chemtrail enthusiasts.

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