Chemtrails
The streaks commonly observed behind high-altitude aircraft are known as condensation trails, or contrails, which form when water vapor from aircraft exhaust freezes into ice crystals in cold, high-altitude atmospheric conditions. This is a well-understood physical process and has been documented since the early days of jet aviation.
Contrails may dissipate quickly or persist and spread depending on temperature and humidity at flight altitude. Their appearance and duration are influenced by weather conditions, not by the release of chemical substances. There is no scientific evidence to support claims that these trails are intentional dispersals of chemicals or other agents. For more information about contrails, please visit https://www.epa.gov/regulations-emissions-vehicles-and-engines/Contrails.
Aircraft emissions do impact our air quality but are a very small fraction of our county’s emissions inventory and what is detected at our monitoring stations. The majority of the emissions that do affect our air quality are primarily from motor vehicles, wood-burning devices (in the winter), and other sources like industrial processes, wildfire smoke, windblown dust, and utilities.