Really good exercise in critical thinking and the OP has exhibited exactly the right response. There is no credible data supporting the premise. Whihc suddenly became the subject of the essay, right? 
This is actually my midterm in the course, the idea is to pick a conspiracy theory and break it down into three parts. In the first part I analyze the theory and attempt to prove it's real (in this case prove that chemtrails are indeed happening). In the second part I analyze it again and attempt to prove that it's false (chemtrails are bogus, you're all insane... blah... blah... blah). In the last part I state where I stand on the issue and give reasons to support my position.
My professor was ecstatic when I suggested chemtrails, nobody has done that as a topic before.