UK government, Google team up to cut aircraft vapour trails
Operation Blue Skies will test AI-guided altitude changes across North Atlantic flight paths
A new UK-backed trial will test whether artificial intelligence can steer aircraft away from forming the vapour trails responsible for a significant share of aviation's climate impact.
Operation Blue Skies, a £5 million, 30-month programme, brings together Google, NATS, the Met Office, the University of Cambridge and Imperial College London to tackle contrails across the North Atlantic.
Contrails appear when hot exhaust from aircraft engines meets cold, high-altitude air, triggering ice crystal formation that can persist and spread into cloud layers trapping heat near the Earth's surface.
Google's technical lead on the trial, Dr Paul Hodgson, told the BBC that contrail warming is responsible for roughly a third of aviation's total climate impact, a figure that dwarfs the fuel penalty involved in avoiding them.
Diverting a flight around a contrail-prone zone typically burns around 100 kg of extra fuel, adding a CO₂ cost Hodgson estimates at under 1% compared with the warming avoided.
Google is going to provide AI, machine learning and satellite imagery for free with an estimated value of approximately £1.4 million, whereas the Department for Transport will give £2.65 million in government funds under the Aerospace Technology Institute Programme.
NATS will be responsible for airspace management, pilot training and safety evaluation by making relatively minor changes in flight altitude (of about 2,000 feet) based on predictions made by Google.
The Met Office will be developing a new UK contrail forecasting system, and Cambridge University and Imperial College London will be carrying out independent assessments of the climate effects of the trial.
The trial focuses on Shanwick Oceanic airspace, the eastern half of the North Atlantic corridor, which the consortium says accounts for roughly 5% of global contrail warming, concentrated heavily in the winter months.
Two operational trial periods, each around four months long, will run during the winters of 2026-27 and 2027-28, observing about 10,000 flights overall.
Only a small fraction of those, estimated at 1% to 5%, will actually be redirected to avoid contrail-sensitive airspace, with testing concentrated on lighter-traffic evening and night windows.
