To ask the Secretary of State for Energy and Climate Change what evidence his Department has (a) received and (b) evaluated on the science of non-carbon dioxide climate change impacts from aviation, including radiactive forcing and the effect of emissions at altitude; and whether his Department is funding any research on total climate impacts of aviation due to radiactive forcing. (231299)

The Department for Environment Food and Rural Affairs (DEFRA) has commissioned a report looking at the effect of aviation on radiative forcing of climate through not only its emission of CO₂, but also NOx and the effects of contrails and aircraft-induced cirrus.

Although much remains to be done on improving modelling at global and regional scales, the report (which is not yet finalised) demonstrates more clearly the effect of NOx emissions from aviation on ozone and methane emissions and the impact of aircraft altitude on temperature.

Mitigation of aviation emissions, including the complex technological and atmospheric tradeoffs, is also discussed in the report. A core issue is how to balance the long-term effect of CO₂ against shorter-term effects such as those from ozone, contrails and aircraft-induced cirrus that have equal or greater radiative magnitude than CO₂. Particular focus has been given to the potential for reducing contrail radiative forcing by modifying flight altitude.