True fact: there's no such thing as “chemtrails.” The word for the trails of vapor sometimes created by aircraft is "contrails," short for condensation trails. They're water. They’ve been understood for almost a century. There's no mystery about it, and no controversy, except for the controversy created by right-wing nutcases.
One of whom, to our shame, is the top health official of the US.
@gleick
Here, on the other side of the planet, they have been known as vapour trails for my entire life. Personally I like that, it's an accurate description.
Language matters.