To add to the discussion....I work in the aviation industry. I too am skeptical of chemtrails for the reasons Mike has cited below and Mathman a few days ago. One thing to add is about the apparent pattern that is made by these supposed chemtrails. I believe they are contrails made by comercial airlines. Just like vehicles drive on roads, so to do airplanes fly on set airways. Intersections in the sky are known as VOR stations, usually situated over airports, both international and region, and also military bases. If you live near one of these VOR stations you will frequently see the criss-cross shapes of the contrails. I am a meteorologist, and I can tell you that the weather also affects what these contrails look like; how long they last, how fast they dissipate, how they move, etc.Amy Van GerpenMike Thompson (29 March 2012)
"MM on chemtrails"
Amen. But from a different angle.
Any engine using fuel produces water vapor. You see it in the tailpipes of cars in the winter especially.
Jet engines produce the same thing and you see it as a white trail.
Do you really think there are tanks of chemicals onboard commercial airlines and controlled by the pilot?
Where are these tanks in the airplane?
Who orders them to dump chemicals?
Where are they instructed to dump chemicals?
Why are the thousands of pilots who run these planes (and have been for decades) completely silent about such a thing? Because it does not exist.
I have heard of cloud seeding to cause rain. That is another operation completely and certainly do not use passenger planes.