AI Tool Reduces Contrail Warming by 69% in Flight Trial

American Airlines and Google announced Thursday that an artificial intelligence tool helped reduce the formation of contrails on transatlantic flights, cutting the climate warming effect of those routes by up to 69 percent in a trial involving more than 2,400 flights from the United States to Europe.

The trial, conducted from January to May 2025, tested AI forecasts integrated into American Airlines' flight planning system. Contrails, the white streaks left by aircraft engines, form when hot exhaust mixes with cold, humid air at high altitudes, creating ice crystals that trap heat in the atmosphere. These clouds contribute 1 to 2 percent of global warming, according to Contrails.org, a nonprofit focused on aviation's climate impact and part of the Breakthrough Energy initiative founded by Bill Gates.

In the study, half of the flights received AI-generated route options to avoid contrail-forming regions, while the other half served as a control group with standard paths. Of the 1,232 flights offered alternatives, 112 pilots and dispatchers selected them, resulting in 62 percent fewer visible contrails compared to similar control flights, based on satellite imagery analysis....