Many, many years ago, I started my career as a Meteorological Technician with Environment Canada.  I used to record, report and send daily weather observations from a small weather station in Atikokan Ontario. I think it’s since been decommissioned.  

Every instrument reading had its place on the observation sheet.  At the end there was a column for remarks.  One such remark that I entered quite frequently was CONTRAILS, or condensation trails. 

I’ve had people tell me these trails of vapour are new: “they weren’t there when I was a kid”  Many are convinced that the trails seen behind airplanes are not actually contrails, but are in fact "chemtrails," part of a conspiracy by the government to poison its own population

Let me start by saying that those trails of vapour in the sky were there when I was a kid…and nobody spent more time looking up at the sky than I did! 

If you look around, especially on social media, you’ll find a long list of conspiracy theories. You can add the Chemtrail conspiracy to this list. This conspiracy holds that the contrails thrown off by commercial jets contain chemicals that serve to dumb down the population, or at the very least control it. The theorists noticed that some contrails don't behave the way they are supposed to, forming strange shapes as they diffuse.

Let me offer two reasons why this conspiracy is nothing more than hot air.

First, adding a payload of chemicals to a jet liner costs money, which would certainly undermine profitability.  Most importantly, scientists are very interested in what's in the atmosphere. They measure the suite of pollutants in the atmosphere down to the trillionth of a millimeter. If an aircraft were intentionally polluting, scientists would notice it."

More now on condensation trails or “contrails”. 

They are the white lines that sometimes form behind high flying aircraft; they are actually a type of cloud.  The cloud forms because jet exhaust contains quite a bit of water.  If the humidity is high, then the contrails can persist for a long time, like clouds do.

When jet exhaust comes out of the engine, it’s superheated.  So the water is in the form of vapour or steam and so it’s invisible.  As it mixes with the surrounding cold air, it very quickly cools down and at a certain point it will condense into water droplets and then freeze into ice.  Because it takes a fraction of a second to do this, there usually is a gap between the engine and the beginning of the contrail.

There are several variables that explain the difference in the “look” of a condensation trail:  the speed of the plane, the temperature of the exhaust, the temperature of the surrounding air and the size of the plane.  Of these, the one that has the greatest effect is the air temperature, which is generally determined by the altitude.  The amount of moisture in the air will determine how long the trail will linger.

 Knowledge is power and now you know…the truth is out there!


Chief Meteorologist

Cindy Day