The consultation says:
4.1 Tackling CO2 is of critical importance, but aviation has non-CO2 impacts through NOx and contrails
4.2 Contrails can persist and create cirrus clouds, and these can contribute to warning although there is some uncertainty as to the extent
4.3 NOx emissions increase levels of ozone (warming effect) and decrease methane (cooling effect) – the net effect is warming but to an unknown extent
4.4 Local air quality is affected around airports via NOx and particulates
4.5 We are working to address non-CO2 impacts in the following ways:
- Many of the measures to improve efficiencies, roll out SAF, and accelerate zero emission flight are expected to have a positive impact on reducing non-CO2 impacts. Where there is evidence to the contrary, we will carefully consider the overall impact on the climate
- We are improving our understanding of non-CO2 impacts and will ensure that the latest scientific understanding of aviation non-CO2 impacts is used to inform our policy
- ICAO now has standards in place to regulate all aircraft emissions with significant climate effects. We will continue to negotiate for these to be improved over time as well as consideration of other measures such as operational guidance and regulation of fuel composition
- We will consider the outcomes of EUROCONTROL’s Contrail Prevention Trial and whether it would be beneficial to undertake similar trials in the UK in the future.
SAF produces less soot (hence possibly fewer contrails) and sulphur (less harm to air quality) when burned, but that does not necessarily mean that using SAF for aviation, and biomass for SAF is the best way ahead.
The overall climate change impacts of aviation, as well as its impacts on the way the resources available to help reduce carbon emissions across all sectors, need to be understood and weighed in a much broader balance.
In other words, aviation cannot commandeer all the resources it needs just because DfT has been led to believe aviation must continue to grow: a holistic global approach is required to tackle the climate change crisis.
15 What could be done further or differently to ensure we tackle non-CO2 impacts from aviation?
Next page: Conclusions