"WASHINGTON, DC – Long-lasting white trails left behind by aircraft are caused by well-understood physical and chemical processes, not a secret, large-scale atmospheric spraying program, concludes new research from Carnegie Science, University of California-Irvine, and the nonprofit Near Zero.

Some groups and individuals allege that the white marks aircraft make across the sky are 'chemtrails,' chemicals sprayed secretly either by the government and or by industry and linked to negative impacts on human health and the environment.

By contrast, scientists refer to the trails left behind by aircraft as condensation trails, or “contrails.”

The current study surveyed  dozens of the world’s leading atmospheric scientists, who overwhelmingly rejected the suggestion that a secret spraying program exists."

Environment News Service had the story August 14, 2016. [2]