The government is definitely not secretly spraying chemicals from planes for nefarious purposes, according to a study whose authors admit that they are unlikely to persuade conspiracy theorists that "chemtrails" do not exist. Researchers from Carnegie Science, University of California Irvine, and the nonprofit organization Near Zero spoke to dozens of top atmospheric scientists and found that 76 out of 77 had seen no evidence whatsoever of any secret chemical spraying, Mashable reports. A 77th reported encountering high levels of atmospheric barium in a remote area with standard 'low' soil barium. according to the study, which was published in Environmental Research Letters.
The researchers say the trails left by aircraft are ordinary condensation trails—contrails—though those trails may be lasting longer than they used to because of climate change, and there are more of them than there used to be because of the growth of air travel. They say they carried out the study to have something on the record to refute the "chemtrails" theories that one survey found were believed by more than 15% of Americans. "I felt it was important to definitively show what real experts in contrails and aerosols think," researcher Ken Calderia from Carnegie Science says in a press release. "We might not convince die-hard believers that their beloved secret spraying program is just a paranoid fantasy, but hopefully their friends will accept the facts." (Read more conspiracy theories stories.)