evidence: Finally, they were presented with the analysis of samples from pond sediment, snow and air that the collectors claim were contaminated with traces of barium, aluminum, copper and strontium from chemtrails. The researchers said that 80 to 89 percent of the samples could be explained by phenomena much more simple than chemtrails. The chemtrails craze likely originated with a 1996 report from the Air Force called "Weather as a Force Multiplier," which speculates how the military could develop weather modification technology by 2025, report Annalee Newitz and Adam Steiner at i09. A patent filed in 1991 for a technique of seeding the upper atmosphere with particles that could reflect sunlight and slow global warming also intrigued theorists. Combined with anecdotal tales of plants dying and people getting sick after planes left contrails above their homes, the conspiracy theory coalesced and took off on the internet in the late 1990s. Since then, the issue periodically pops up in the media. According to Public Policy Polling, about five percent of Americans believe in chemtrails. That’s more than the four percent who believe lizard people are taking over our politics but much less than the number who believe in bigfoot or that global warming is a hoax.