AI Technology Helps American Airlines Cut Heat-Trapping Contrails by 62%

American Airlines partnered with Google to test artificial intelligence technology that predicts where airplane contrails form, allowing pilots to adjust routes and reduce climate impact. The trial involving 2,400 flights showed a 62% reduction in contrail formation and 69% less warming effect with no significant increase in fuel costs.

A groundbreaking partnership between American Airlines and Google has demonstrated how artificial intelligence can dramatically reduce airplane contrails that contribute to global warming, the companies announced Thursday.

The collaboration used AI forecasting technology to predict where condensation trails would likely develop when aircraft travel through cold, humid atmospheric conditions. These contrails form when ice crystals develop around soot particles from jet engines, creating cloud formations that trap heat in the atmosphere.

Google’s artificial intelligence system identifies areas where contrails are most likely to occur, allowing American Airlines to incorporate this data into their flight planning software. Pilots can then make minor altitude adjustments or choose alternate routes to bypass these problem zones.

Both companies describe this approach as potentially one of aviation’s most practical and affordable climate solutions currently available.

The airline industry faces mounting demands to address its environmental impact. Despite appearing as thin white streaks across the sky, contrails account for approximately 1% to 2% of global warming, according to Contrails.org, a research nonprofit within Bill Gates’ Breakthrough Energy initiative that participated in this study.

While switching to sustainable aviation fuels offers significant emission reductions, making small route modifications presents a much less expensive alternative to cutting contrail formation.

Most contrails disappear quickly, but under extremely humid conditions, some can linger for hours or even days. Previous research indicated that minor flight path changes could eliminate much of this warming effect while using only minimal additional fuel – a hypothesis this trial set out to verify.

The experiment tracked 2,400 transatlantic flights between the United States and Europe. Google’s research, published in a Thursday blog post, revealed that half the flights received contrail-avoidance routing while the remaining flights served as a control group.

Among the 112 flights that used the alternative routing, contrail formation dropped by 62% compared to standard flights. Researchers calculated this reduction decreased the climate warming impact from those flights by approximately 69%.

The testing period ran from January through May 2025, with Flightkeys flight planning service joining American Airlines, Google, and Contrails.org in the research effort.

“We know that aviation is one of the hardest, most difficult sectors to decarbonize,” explained Dinesh Sanekommu, who oversees Google’s contrail research. “We think there’s a way that AI can help make that a reality. And the hope is, whether it’s these AI-based forecasts, whether it is doing these operational scientific demonstrations together, they all add a little bit of evidence and generate a bit of data that helps make the right decisions in the long run.”

This project expands on previous work between Google, American Airlines, and Breakthrough Energy that began in 2023. Their earlier contrail reduction efforts involved manually identifying flights rather than integrating the technology directly into flight planning systems.

Looking ahead, Sanekommu indicated plans for expanded testing and collaboration with additional flight planning software companies to incorporate contrail prediction and avoidance capabilities into their platforms.

Airlines often hesitate to modify routes due to concerns about increased fuel expenses, but the trial revealed no meaningful statistical difference in fuel consumption between the two flight groups.

International coordination among pilots and air traffic controllers across different airspace regions presents another obstacle, noted Thomas Walker, an aviation climate researcher at Boston’s Clean Air Task Force. Walker mentioned that discussions with other major airlines about contrail avoidance have encountered “a little bit of pushback.”

However, Jill Blickstein, American Airlines’ vice president of sustainability, reported that the trial demonstrated dispatchers and pilots had no difficulty implementing and executing alternative flight plans designed to avoid contrail formation.

Walker, who serves as CATF’s senior transportation technology manager, pointed out that the North Atlantic corridor represents a contrail hotspot, making avoidance efforts in that region particularly valuable.

According to Walker, while Europe has conducted route adjustment trials, this represents the largest such experiment he’s aware of in the United States, calling it “a pretty big step in the right direction.” He expressed hope that American Airlines’ successful results would motivate other carriers to participate in similar programs.

American Airlines has not yet incorporated contrail avoidance into its standard flight planning procedures. The airline indicated interest in continuing partnership research, potentially examining different routes and departure times to address additional scientific questions about contrail formation and climate impact.