AI to help planes avoid climate-warming 'sky graffiti'

Across the sky, aircraft leave white trails known as contrails. These icy clouds contribute to climate change, prompting scientists to explore ways to mitigate their impact. A £5 million UK trial, dubbed Operation Blue Skies, aims to use artificial intelligence to predict where warming contrails will form, allowing planes to steer clear of those zones.

The project, involving Google, the UK government, the Met Office, air traffic control provider National Air Traffic Services (NATS) and academic researchers, will focus on the Shanwick Oceanic airspace in the eastern North Atlantic corridor, responsible for about 5% of global contrail warming. Contrails form when hot exhaust from aircraft engines mixes with cold air at high altitude, creating ice crystals that can linger and trap heat, exacerbating global warming.

Dr Paul Hodgson, Google's technical lead for Operation Blue Skies, likens contrails to "sky graffiti," estimating they could account for up to a third of aviation's climate-warming effects. While the exact figure remains uncertain, scientists are convinced it represents a significant issue. The trial will leverage satellite imagery and flight data to identify areas where contrails frequently develop, combined with weather patterns to forecast future contrail formation.

This information will be relayed to NATS, enabling air traffic controllers to guide pilots to avoid those regions. Minor altitude adjustments of around 2,000 feet, already routine to circumvent turbulence and adverse weather, will be implemented by NATS. The trial will take place during lower-traffic evenings and nights in the winters of 2026-27 and 2027-28, with approximately 10,000 flights expected through the airspace during the trial periods.

The Department for Transport is contributing £2.65 million to the program, while Google is providing £1.4 million in AI research, engineering, and computing resources. Aviation Minister Keir Mather highlighted the trial as a British innovation, emphasizing its potential to enhance flight cleanliness. While minor fuel consumption increases may accompany the altitude changes, Dr Hodgson asserts that the climate benefits of preventing contrail warming outweigh the additional carbon emissions.