Photo of ‘chemtrails’ shows contrails made from water vapour

A post on Facebook shows two pictures of the sky: one of clouds with the caption “these are clouds”, and the other of several trails from planes, with the caption “these are chemtrails”. 

While it’s true that one of the images does show clouds, the other does not show “chemtrails”. It shows contrails, which consist of water vapour that freezes in the cold temperatures at high altitude forming long thin lines of cloud. 

Depending on the humidity and temperature of the air, the tiny ice crystals can either change directly from a solid to a gas (becoming invisible after a few minutes) or remain in the air as water or ice, which means they stay visible for several hours. 

Not all planes will produce contrails. Slight differences in flight altitude and the efficiency of the engine mean planes that look similar from the ground may produce different trails. 

At Full Fact we’ve written about the “chemtrail” conspiracy theory, which claims that the white lines seen behind planes are actually harmful chemicals being deliberately sprayed into the atmosphere, multiple times before. 

It is commonly claimed that the chemicals in “chemtrails” are either designed to poison or harm the population in some way, or manipulate the weather to simulate the effects of climate change, for example. 

While these claims are extremely popular online, there’s no evidence to support them. 

Image courtesy of Aditya Vyas