Question to the Department for Transport:

To ask the Secretary of State for Transport, what assessment her Department has made of the potential merits of contrail-mitigation measures in reducing aviation's climate impact.

The Government recognises that aviation has non-CO2 impacts such as contrails which may have significant warming impacts on the climate, although significant scientific uncertainties remain.

The Government has funded 14 projects as part of our Non-CO2 R&D Programme to better our understanding of aviation’s non-CO2 impacts and to identify and develop potential mitigation options.

The Department also established a Contrail Impact Mitigation Task and Finish Group under the Jet Zero Taskforce which assessed the UK’s capability to undertake contrail avoidance manoeuvres as a means of reducing aviation’s non‑CO₂ climate impacts.

The report highlighted that the atmospheric conditions in the North Atlantic make it prone to forming persistent warming contrails. The report was published on 17 March 2026 and one of the key recommendations from this report was for the UK to undertake large-scale trials in the North Atlantic. The Department is carefully considering all the recommendations and is currently exploring options to fund a large‑scale trial in UK controlled airspace.