Call me a skeptic. "Chemtrails" are water vapor, with a bit of sulfur dioxide and nitrogen oxide. They come from burning jet fuel.
1) the people who are alarmed about this phenomenon lack and understanding of basic principles of weather and clouds
2) credible weather experts are not concerned with this issue
3) this would be a massive undertaking, involving huge numbers of people and billions of dollars
4) people who believe in chemtrails cannot agree on what they allegedly contain, or what their purpose is