A trial backed by the UK government and Google will use AI to look at how aircraft can reduce their vapour trails by tweaking their flight paths.
Operation Blue Skies comprises two trials that will be conducted during the winter in the Shanwick Oceanic airspace above the eastern half of the North Atlantic corridor.
The trials will evaluate the feasibility and environmental benefits of adjusting the altitude of commercial flights to avoid the atmospheric conditions that contribute to the formation of persistent, climate-warming vapour trails.
Atmospheric modelling shows that the Shanwick airspace accounts for around 5 per cent of global contrail warming, a significant part of which is concentrated between November and February.
Operation Blue Skies is designed to target this high-impact window by using AI models to identify where and when interventions have the greatest potential to reduce contrail-related climate impact.
Shanwick is managed by the UK’s NATS air traffic control service, which is part of the trial along with Imperial College London, Cambridge University, the Met Office and Contrails.org, a non-profit dedicated to reducing aviation’s climate impact.
Vapour trails, also known as contrails, form when water vapour in jet engine exhausts condenses and freezes around soot particles and other aerosols in the cold, humid air of the upper atmosphere.
Many disappear quickly, but persistent warming contrails trap outgoing heat, accounting for roughly one-third of aviation's total climate impact.
Aviation minister Keir Mather said the government was looking “to find practical ways to make flying cleaner”.
“By testing small tweaks to flight paths over the Atlantic, we can cut the vapour trails left behind by planes,” Mr Mather said.
Marc Stettler, professor of transport and the environment at Imperial College London, said a study in 2020 found that small changes to flight paths could reduce the climate impact of contrails.
“Operation Blue Skies is a chance to test that idea in the real world and on a scale we've never seen before,” said Prof Stettler.
“At Imperial, our role is to independently assess what happens, from the effects on airline operations to the benefits for the climate, and provide the evidence needed to decide whether this approach could become part of everyday aviation.”
Operation Blue Skies is a £5 million, 30-month programme, partly funded by £2.65 million from the Department for Transport.
Google UK is participating on a pro bono basis, contributing £1.4 million worth of AI research expertise, engineering time and high-performance computing infrastructure.
