UK and Google launch airspace-scale trial to cut aviation contrails
A 30-month UK-Google trial will reroute hundreds of North Atlantic flights to avoid contrail-forming zones, aiming to cut aviation's climate impact.
The British government and Google have launched a landmark trial to reduce the climate impact of aviation by altering the flight paths of hundreds of commercial aircraft over the northeastern Atlantic Ocean. The 30-month programme, named Operation Blue Skies, will run test periods over the next two winters, during which air traffic controllers will direct some flights to deviate by up to 2,000 feet to avoid areas where condensation trails, or contrails, are likely to form.
Contrails form when aircraft fly through cold, humid air, and ice crystals condense around soot particles from engine exhaust. These thin clouds trap heat and contribute to global warming, accounting for an estimated 1% to 2% of Earth's warming, according to the nonprofit research group Contrails.org.
The trial will take place in the Shanwick Oceanic Control Area, a busy gateway for Europe-North America traffic and a known hotspot for contrail formation. Around 10,000 flights are expected to pass through the airspace during testing, with hundreds of those flights being rerouted. The goal is to demonstrate a statistically significant reduction in contrail formation on an airspace-wide scale, moving beyond previous single-airline trials.
Google UK is providing AI-powered forecasts to identify contrail-prone regions, while the UK government is funding more than half of the £5 million ($6.76 million) study. The consortium also includes the Met Office, NATS, Imperial College London, and the University of Cambridge.
Paul Hodgson, Google's technical lead for the project, said the airspace-scale approach can show how multiple planes can be moved simultaneously away from contrail-forming areas, potentially providing a blueprint for other regions. The trial builds on earlier work, including a collaboration between Google and American Airlines that reduced contrail impact on some flights.
UK Aviation Minister Keir Mather said the partnership aims to support British experts and innovators in finding practical ways to make flying cleaner. An Imperial College London study in 2020 suggested that small flight path changes could reduce contrail climate impact, and Operation Blue Skies will test this idea in real-world conditions on an unprecedented scale.