Cathay Pacific and Google have launched a partnership to study contrails and their role in aviation’s climate impact. Cathay is the first Asian-Pacific airline to collaborate with Google in trialing its AI-powered contrail mitigation technology, and indeed the first airline in the world to test contrail avoidance on ultra-long-haul flights.
The contrails or condensation trails following in the wake of aircraft travelling at high altitude, form when planes fly through cold, humid air. Often, they quickly disappear, yet some remain and spread into cloud cover that traps heat. These lingering contrails may contribute roughly a third of aviation’s overall climate footprint, according to research, and therefore they, like CO₂ emissions, should be studied in greater detail. Cathay is actively working to improve its environmental impact – be it through fleet modernization, SAF, other operational efficiency initiatives, or collaboration with Google to support the scientific understanding of contrails. It uses Google’s AI-based predictive models, satellite imagery, and intelligent weather forecasting to identify zones likely to produce contrails, giving dispatchers and pilots the information needed to adjust altitude – similar to how they already avoid turbulence. These forecasts are integrated into Cathay’s in-house Electronic Flight Folder system, using onboard Wi-Fi to deliver real-time updates to pilots.
In late 2025, a trial began that targeted over 100 flights, of which more than 80 actually flew avoidance routes; Google estimates these cut contrails’ warming effect by about 40%. The Hong Kong–Singapore route was especially effective, generating over half of the trial’s total climate benefit through small altitude tweaks.
Encouraged by these results, the companies – joined by nonprofit Contrails.org – are moving into a larger second phase across Cathay’s Asia and transpacific network, aiming to build a stronger evidence base to guide future airline practices and policy decisions industry-wide.
Lawrence Fong, Director Digital and IT, Cathay, declared: “Aviation needs solutions to address climate change, and AI is accelerating that progress. This partnership combines Cathay’s operational expertise with Google’s world-class AI capabilities to tackle complex sustainability challenges at scale. At Cathay, we believe innovation should deliver tangible and meaningful impact, and this collaboration sets a new benchmark for leadership in our industry.”
Michael Yue, Managing Director and General Manager, Google Hong Kong, detailed: “At Google, we believe AI has the power to help address complex environmental challenges and our partnership with Cathay Pacific is a prime example of this in action – researching how predictive AI can be deployed in live operations to help address the climate impact of contrails with today’s aircrafts and today’s fuel. This work reflects our ongoing commitment to developing sustainable solutions that deliver lasting impact, and we’re excited to expand our trial with Cathay Pacific and continue contributing to open climate science together.”
