Next to the impacts of CO2 emitted by aircraft on the climate, aviation has so-called non-CO2 climate impacts. One of the main non-CO2 impacts is the formation of contrails; by some measures, its contribution to global warming is larger than that of aviation CO2 emissions.
Contrails are formed when aircraft emit particulates, and the quantity of particles emitted is driven by the concentration of aromatics in the fuel.
One of the ways to reduce the climate impacts of contrails is therefore to reduce the aromatics content, which is an expected result of the proposed obligation to blend sustainable fuels (SAF) in aviation fuels in the European Commission’s ReFuelEU Aviation proposal, provided that the aromatic concentration in the fossil part of the blend will not increase.
By setting up a monitoring system for the aromatics content in the fuel, an assessment could be made whether the impacts of SAFs on the non-CO2 climate impacts of aviation will be realised.
The report has been written for the Dutch Ministry of Transport and Water Management, which has sent it to the Dutch Parliament.