The first time I ever heard a contrail/chemtrail conspiracy theory, I was about 5 and eavesdropping on a group of women that included an aunt who was very strange.
And why are these chemicals are supposedly being sprayed? Giant bugs? Crop manipulation from above?
Here’s my perception of a plausible chemtail justification.
They began about the time of HAARP and when Cllinton was President.
Consider a Synthetic Aperture Radar, able to glean 1mm resolution on anyplace on the planet.
It would require a type of conduit to communicate the signals over the globe, more extensive than satellite communications.
The best security sometimes is to hide a sensitive system in the open, such that nobody suspects the conspiracy could be true as it would be too pervasive.
Now consider when Gore lost his Presidential bid. He would have had access to sensitive data regarding such a system. Once out of office, he likely would confuse the thermodynamic quantity of heat with temperature.
This is about the time Gore promoted the Global warming sham. He was thought to be very clever amongst the environmental power structures, in that he could level charges about Global Warming, but those in the know would not be at liberty to expose him.
This also happened about the time of our entree into the Muslim wars in Iraq, Afghanistan, etc.
This CT is consistent. I do know at the time of heir first appearance, Air Force Flag Ranks charged with such topical programs were aware something was behind the charges, but they were not considered to have a need to know.
Meanwhile, jet engine engineers were also consulted and there was nothing new in their combustion or aerodynamic designs which would simply justify their appearance as “condensation trails”.
The volume of expansion simply indicated there were a slight feed of some commonly placed chemicals into all commercial jet aircraft and not challenged by the corporate structures.
If there weren’t any basis behind chemtrails, the environmental regulators would be all over the topic because they were associated with deep pockets in the airline industry, their common operations, and they had universal impact upon the quality of the public environment.
I chalk them up to a black op of technology giving us one leg up upon any adversary, but have been around long enough now, that one can bet our adversaries have similar if not more extensive capabilities associated with the Open Skies treaties.
Just my CT 2 cents.