The contrail is now being asked to file its own climate note

The North Atlantic trial is Operation Blue Skies. The University of Cambridge describes it as a 5 million pound, 30-month programme, partly funded by 2.65 million pounds from the Department for Transport, with two operational trials in the winter months across NATS-controlled Shanwick oceanic airspace, the eastern half of the North Atlantic corridor. It says atmospheric modelling puts Shanwick at approximately 5% of global contrail warming, with a large share in the winter window from November to February, which is the window the note refers to.

The fleet system is Google's contrail work. Google's research page describes a machine learning Contrail Likely Zone model, a deep neural network that takes weather features and is trained on satellite contrail detections. Cathay Pacific's announcement of 7 September 2026 says its partnership with Google combines AI predictive models, satellite imagery detection and weather data to forecast contrail-forming zones, and that Cathay is the first airline to test avoidance on ultra-long-haul flights. The EU project is E-CONTRAIL, which the European Commission's CORDIS page describes as using satellite imagery and an artificial neural network to study contrails and aviation-induced cloudiness.