Question to the Department for Transport:

To ask Her Majesty's Government what analysis they have carried out into the trade-off between additional CO2 emissions generated by rerouting aircraft for contrail prevention and the climate mitigation benefits of condensation trail prevention.

Alongside “Aviation 2050 – The Future of UK Aviation: A Consultation”, the Government published a short paper commissioned from Professor David Lee of Manchester Metropolitan University entitled “The current state of scientific understanding of the non-CO2 effects of aviation on climate”.

This paper makes clear that contrail avoidance through rerouting would require accurate meteorological prediction of potential contrail-forming areas and an agreed metric by which to ascertain that the flight’s total climate impact was being reduced. Neither of these are available today but the Government continues to follow developments closely.

The Government has not commissioned any further analysis into the climate trade-offs associated with rerouting aircraft for contrail prevention, though we continue to keep the issue under close review and in this vein I refer the Noble Lord to the answer I gave on 22 December 2020 to Question UIN HL11424