Built for a Better World

Condensation trails, or “contrails,” are clouds that form when jet engines shoot hot air and soot particles into pockets of cold, damp air high in the atmosphere. Those contrails might be responsible for most of the airline industry’s warming impact — even more than burning jet fuel — according to a 2022 report from the U.N. Intergovernmental Panel on Climate Change (IPCC).

Now, airlines including American, Delta and KLM are starting to explore whether they could reduce their warming impact by redirecting a small number of planes to fly slightly lower or higher to avoid creating contrails.