Condensation trails from biofuels/kerosene blends scoping study

The purpose of this report is to inform the European Commission on issues related to contrail formation with respect to the introduction of biofuels and blends (and similar alternative fuels) into the aviation transport system. The report describes the physics of contrail formation and how exhaust soot and other particles may affect contrail properties and eventual climate impact. Soot and particle formation depend on fuel composition and on details of the combustion process and the engine’s influence on the latter. All these processes are discussed. Current uncertainties are stressed and ways to overcome them are suggested. The introduction of aviation biofuels has a potential for a climate benefit in principle, but further research is recommended in order to employ constrained stocks of biofuels in a climate optimal way