An American Airlines plane flying in against a clear blue sky

Contrail avoidance

American is helping lead the way toward developing and testing contrail avoidance methods. Contrails — or condensation trails — form when airplanes fly through layers of humidity, and they may account for a significant portion of aviation’s global warming impact, according to the IPCC. Contrail avoidance strategies, while still in the early stages of exploration, hold the promise of being among the most cost-effective and scalable climate solutions available in the near term.

Diagram showing contrails and their effect on warming — Contrails form when a plane's hot, humid exhaust mixes with cool, humid air high in the atmosphere and creates ice. Contrails are similar to naturally occurring cirrus clouds — and they affect the climate in the same way. But aviation artificially increases the amount of cirrus clouds in the atmosphere. During the day, contrails reflect some sunlight back into space, and therefore have a weak cooling effect. At night, contrails exclusively trap heat, meaning they have a strong warming effect that more than offsets the weak daytime cooling effect. Persistent nighttime contrails — meaning those that don't dissipate quickly — have the most warming impact. Avoiding these is the highest-value intervention.

Teaming up with Google Research, Breakthrough Energy and Flightkeys

In 2023, we participated in a first-of-its kind study (opens in new tab) led by Google Research and Breakthrough Energy that determined commercial flights can verifiably avoid creating a contrail.

After laying the groundwork in 2024, we’re conducting additional research in 2025 with our Google Research, Breakthrough Energy and Flightkeys partners to find ways to replicate and scale the findings. The goal is to introduce contrail avoidance strategies into the flight planning system, so that dispatchers can select routes that avoid areas that are at risk of creating persistent contrails.

More on this cutting-edge research

Diagram showing the effects of contrails on warming

Breakthrough Energy's initiative

Picture of Marc Stettler alongside a quote from him — "As a scientist and engineer, there's no other problem I've worked on that has such a high potential to deliver meaningful climate benefits." — Marc Stettler, Professor in Transport and the Environment, Imperial College London

Testing and integrating contrail avoidance strategies

Google Research blog post

Visit our Resource Center for links to numerous American Airlines documents, policies, webpages and other sources of information about our company’s approach on various sustainability topics.

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Contrail avoidance

Teaming up with Google Research, Breakthrough Energy and Flightkeys

Sustainability at American Airlines

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