There’s a lot of jet contrails in the sky today, and that’s not surprising considering my proximity to Albuquerque’s Sunport (an international airport) and Kirtland Air Force Base. The contrails are the long, crisscrossing lines formed by passing planes. Unfortunately, many people don’t understand what contrails are and make wild “chemtrail” accusations.
If you’ve never heard before, the chemtrail theory is that some of the white contrails you see left by jets are actually chemicals placed there by the government and major airlines for unknown and assuredly nefarious reasons. These theories are outrageous, disorganized, and completely unfounded. Please do not believe them. This conspiracy theory is so pervasive that even well-meaning people will sometimes use the word “chemtrail” when they mean contrail.
How do they form?
Contrail is short for condensation trail. They form when air in the upper troposphere (the height jets fly) is supersaturated and below -40 F. Supersaturated means means the air holds the enough moisture to spontaneously form clouds, but lacks the necessary condensation nuclei. Condensation nuclei are tiny specks of dust or other material that are at the center of every raindrop or ice crystal.
The contrails form when water vapor from the jet’s exhaust cools and mixes with the surrounding air. The vapor condenses into droplets and then freezes into ice crystals, forming the cloud. Contrails can persist for quite a while if the humidity of the air is high enough. Eventually however, the contrail cloud will sublimate, transitioning from a solid state directly to gas.
A Climate Issue
Clouds are a tricky issue when modeling climate change. They can have both a warming and cooling effect. They cool the planet by reflecting incoming solar radiation and warm the planet by trapping heat radiated from the surface. The exact balance of this depends on the height of the cloud. Lower clouds tend to have a overall cooling effect and higher clouds have an overall warming effects. Contrails, as high clouds, have a warming effect on the planet. They can cover up to 10% of the sky in high-traffic regions. As we continue to battle climate change, contrails are yet another thing we will have to overcome.
I have found the greatest website for contrail information! For anything you could possibly ask, or for a scientific response to every question raised by chemical conspiracy theorists, visit contrailscience.com. It is authored by a pilot named Mick West and I cannot say enough good things about it. Please read it, spread the knowledge, and help me chip away at this ridiculous chemtrail debate.
Til’ next time!