Google and Cathay Pacific report an estimated 40% cut in contrail warming

Google and Cathay Pacific announced an expanded AI-powered contrail-avoidance trial on September 7, following an initial operational run that began in late 2025. The project connects atmospheric forecasts with flight planning so crews can make small altitude adjustments when conditions allow.

Why those white streaks matter

Contrails are thin white streaks that form behind aircraft in cold, humid air. Most disappear quickly, but persistent trails can spread into cloud-like formations that trap heat. Google and Cathay Pacific cite an estimate that these persistent contrails account for roughly one-third of aviation’s total climate impact.

The trial targeted more than 100 flights across Cathay Pacific’s network, and more than 80 followed avoidance routes. Airspace and payload restrictions kept some targeted flights from participating. Google’s satellite-image analysis estimates that participating flights reduced the warming impact of contrails by roughly 40%. That percentage concerns contrail warming on the participating flights, not their total emissions or aviation emissions overall.

Forecasts enter an existing cockpit workflow

The system combines AI-based predictive models, satellite-image detection tools, weather intelligence and flight information to identify cold, humid zones where persistent contrails are likely. Cathay delivers the forecasts through its Electronic Flight Folder alongside real-time operational information. Dispatchers and pilots can evaluate the guidance and make small altitude adjustments, using an operational approach similar to avoiding turbulence. Safety and normal flight constraints remain decisive.

A wider test follows the Hong Kong–Singapore result

The Hong Kong–Singapore corridor was among the tested routes, and actions there accounted for more than half of the trial’s estimated climate-impact reduction because conditions often favor persistent contrails. Cathay Pacific is Google’s first commercial airline partner for this technology in Asia-Pacific and the first airline to test contrail avoidance on ultra-long-haul flights. The partners are moving into a larger second phase across Cathay’s Asian and trans-Pacific network, including randomized trials with Contrails.org. Further research is still needed to establish fleet-wide and airspace-wide benefits, operating limits and the feasibility of scaling the system.