Cathay Pacific and Google collaborate on AI-driven contrail research to mitigate aviation's climate impact through innovative flight trials.
Cathay Pacific, one of Asia's most established international carriers with a global network spanning passenger and cargo operations across the Americas, Europe, the Middle East, Africa, and Asia-Pacific, today announced a partnership with Google to advance research on contrails and their contribution to aviation's climate impact. The collaboration positions Cathay Pacific as Google's first commercial airline partner in Asia-Pacific to trial its AI-powered contrail mitigation technology, and the first airline globally to test contrail avoidance on ultra-long-haul flights.
The partners have begun trials to evaluate the operational feasibility and constraints of contrail avoidance across Cathay Pacific's extensive network. The trials contribute new data to global contrail research and advance understanding of contrail formation and avoidance in the Asia-Pacific region - a geography underrepresented in previous studies. The real-world data gathered through the trials will help the industry better understand the climate benefits of contrail avoidance in actual operational environments.
The thin white lines that sometimes form behind aircraft are known as contrails, or condensation trails. They are clouds that form when aircraft fly through cold, humid conditions at high altitudes. While many disappear quickly, some persist and spread into broader cloud formations that can trap heat in the atmosphere. Previous research suggests these persistent contrails could account for around one-third of aviation's total climate impact, making them an important area of study alongside carbon dioxide (CO2) emissions.
Cathay Pacific recognizes aviation's contribution to climate change and is addressing its climate impacts through multiple approaches. Reducing CO2 emissions remains a primary focus through fleet modernization, operational efficiency improvements, and the adoption of sustainable aviation fuel (SAF). At the same time, the airline acknowledges the importance of growing scientific understanding of non-CO2 climate effects, including contrails. Through this partnership, Cathay Pacific and Google are supporting contrail research using real-world operational data from flight trials, building understanding of the impact of individual contrails and exploring how contrail avoidance could be implemented and managed at scale across the aviation industry.
Google's contrail mitigation solution combines AI-based predictive models, satellite imagery detection tools, and weather intelligence to forecast contrail-forming zones. This data allows flight dispatchers and pilots to make informed altitude adjustments, navigating around these zones much as they routinely do to avoid turbulence.
Onboard, Cathay Pacific draws on its modernized fleet capabilities, combining in-flight Wi-Fi connectivity with its proprietary, in-house-developed Electronic Flight Folder (EFF). The EFF system equips pilots with dynamic Google contrail forecasts and real-time operational parameters, enabling informed cockpit decision-making without disrupting normal operations.
An operational trial began in late 2025, targeting more than 100 flights across Cathay Pacific's network. More than 80 flights followed contrail-avoidance routes, and Google estimates these flights achieved roughly a 40 percent reduction in the warming impact of contrails. Not all of the targeted flights participated, owing to factors including airspace and payload restrictions - operational considerations that remain the subject of further study.
The Hong Kong–Singapore corridor was among the routes tested, as flights in this airspace frequently encounter conditions conducive to persistent contrails. Early analysis indicates that minor altitude adjustments can successfully prevent contrails, with actions taken on this single route accounting for more than 50 percent of the trial's total climate impact.
'Aviation needs solutions to address climate change, and AI is accelerating that progress,' said Lawrence Fong, Director Digital and IT at Cathay. '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 of Google Hong Kong, said: '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 aircraft 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.'
The initial trial provided valuable experience in integrating predictive AI data into live flight planning to support contrail avoidance at the flight level, while bringing together the operational and technical stakeholders needed to make such trials possible. Although the partnership delivered encouraging results on individual flights, further trials and research are needed to assess the benefits of applying contrail avoidance measures across airlines and airspaces. Robust scientific evidence will enable further industry consideration and policy development by airlines, regulators, and other industry participants.
To that end, the partners are embarking on a larger second phase of flight trials to generate a broader set of real-world operational data and further insights across Cathay Pacific's Asia and transpacific network. Contrails.org, a nonprofit initiative dedicated to advancing the science of contrail mitigation, is also a partner in the project. The ongoing partnership aims to generate a robust operational dataset to further scientific understanding of contrail avoidance and help inform future industry best practices.
The collaboration is not merely a research exercise - it positions Cathay Pacific and Google at the forefront of a coordinated effort to reduce aviation's non-CO2 climate impact using today's aircraft and today's fuel.
