Key facts
- A new UK trial will use AI to predict and help planes avoid forming climate-warming contrails.
- The 30-month Operation Blue Skies project is a collaboration between Google, the UK government, and aviation bodies.
- The trial will focus on the Shanwick Oceanic airspace over the North Atlantic.
- AI will analyze satellite and flight data with weather patterns to forecast contrail formation.
- Air traffic controllers will guide pilots to adjust flight altitudes to avoid contrail-prone areas.
- The project aims to reduce aviation's climate impact, with initial trials suggesting significant contrail warming reduction.
A new £5 million UK trial, Operation Blue Skies, is set to investigate how artificial intelligence can help reduce the climate impact of aircraft contrails. Contrails, or vapour trails, are formed when hot exhaust fumes from planes mix with cold, humid air at high altitudes, creating ice crystals that can persist and spread, forming clouds that trap heat. Scientists estimate that contrail warming accounts for a significant portion of aviation's climate impact, potentially as much as a third.
The 30-month project brings together Google, the UK government, the Met Office, air traffic control provider NATS, and academic researchers. The initiative will focus on the Shanwick Oceanic airspace, a key corridor over the North Atlantic that contributes approximately 5% to global contrail warming.
Google will leverage its AI capabilities, using satellite imagery and flight data to identify historical contrail formation patterns. This data will be combined with weather forecasts to predict atmospheric conditions conducive to contrail development. Air traffic controllers at NATS will then use this information to guide pilots to adjust their flight paths, primarily by changing altitude by around 2,000ft, a common practice to avoid turbulence.
Dr. Paul Hodgson, Google's technical lead for the project, highlighted the potential significance of contrails, stating that their warming effect is substantial. He acknowledged the uncertainty in precise figures but emphasized the problem's scale. The trial aims to mitigate this impact, with previous airline-level tests suggesting reductions of 60-70% in contrail formation or warming. While changing altitude may slightly increase fuel burn, initial modelling indicates the additional CO2 emissions are minimal compared to the climate benefit of preventing warming contrails.
The Department for Transport is contributing £2.65 million to the program, with Google providing £1.4 million in AI research, engineering, and computing infrastructure. Aviation Minister Keir Mather described the project as a world-first, showcasing British innovation in making flying cleaner. Testing is planned for selected evenings and nights during the winters of 2026-27 and 2027-28, when air traffic is lower. The results are expected to be published for wider scientific scrutiny.