The United Kingdom is preparing to test whether small changes to aircraft flight paths can reduce contrails that contribute to global warming. The trial will take place in the busy Shanwick airspace over the North Atlantic, west of Ireland, involving scientists, air traffic controllers and relevant British government officials.

Aircraft engines release warm exhaust and water vapour, which can mix with moist conditions at high altitude to form tiny ice particles. Scientists have long warned that these particles can remain in the sky and form cloud-like layers that trap heat in the atmosphere. The planned effort is among the largest tests of its kind globally.

The project will use weather data and artificial intelligence analysis to identify altitudes where long-lasting contrails are less likely to form. Selected flights will then be instructed to fly with slight altitude adjustments. The test is intended to assess whether such operational changes can lower the formation of persistent contrails in a heavily used air corridor.