The chemtrail conspiracy theory originated in the late 1990s, fueled by misinterpretation of a 1996 U.S. Air Force report on weather modification.

The theory began when a U.S. Air Force report suggested future weather control technologies, which conspiracy theorists wrongly interpreted as evidence of current chemical spraying. This misunderstanding, combined with internet forums and media amplification, allowed the theory to spread widely despite lacking factual basis.