As someone who works in the Jet Fuel Industry I have a little inside knowledge I can drop...

The Jet Fuel Industry had to respond to all the people complaining about these "contrails". Turns out these are not made by the fuel or anything being brought up to the sky by commercial aircraft, commercial aircraft are a part of this but they are not releasing particulate in the atmosphere. The fuel used by commercial aircraft is HIGHLY CONTROLLED and very clean. ASTM Global funded a Coordinating Research Council study to look into this issue, that study was abruptly canceled and produced no report. Why because of the answer to what is causing this "chem trail phenomena" which is not the fuel, therefore the Jet Fuel industry can't do anything to change what's happening.

So what is being done to create these things in the sky we all see clear as day? I am making a youtube film about all this, but here it is: The Military is releasing particulate at very high altitudes by small unseen aircraft from the ground with the naked eye. You would have a VERY difficult time filming the aircraft releasing the particulate. The particulate is released over known commercial flight patterns to take advantage of the mixing of the air done by the jet engines.

So in Short the Military releases the particulate at high altitudes, it comes down in a unseen mist, when the commercial planes fly through it, their engines mix the air and the particulate leaving behind the long white silky lines across the sky. These planes are just "leaving natural contrails" because they are not actually doing anything abnormal. It is the air that is already filled with particulate from above that is abnormal and causing the "chemtrails" to be made.

This is the best documentary to date on the subject: