Question to the Department for Transport:

To ask Her Majesty's Government what assessment they have made of the impact on the climate from indirect warming caused by condensation trails from cruising aircraft.

The recent publication “The Contribution of global aviation to anthropogenic climate forcing for 2000 to 2018” by Lee et al., 2020 presents the most up to date scientific analysis of aviation’s climate impacts, including contrails. The publication shows that contrail cirrus formation accounts for a large proportion of aviation's climate impact, however large uncertainties remain in determining the climate effects of contrail formation.

As stated in the 2018 Aviation 2050 consultation, the Government will continue to keep non-CO₂ emissions from aviation under review and adjust its policy as more evidence becomes available.

I will place a copy of “The Contribution of global aviation to anthropogenic climate forcing for 2000 to 2018” by Lee et al., 2020 in the libraries of both Houses.