Flugverkehr und Klimaschutz

Abstract

International air traffic is not yet embedded in international frameworks to reduce anthropogenic greenhouse gas emissions, apart from the EU emission trading system. This paper reviews the state of knowledge on the climate effects due to aviation. Recent findings reveal a much smaller radiative forcing of line-shaped contrails than previously estimated. The greatest uncertainties regarding aviation’s climate effects revolve around changes in cirrus cloud properties. The paper addresses issues on how to include aviation in international frameworks on climate protection. Today’s proposed methods to cover non-CO2 effects from air traffic (Radiative Forcing Index and Emission Weighting Factor) are shown to include significant shortcomings that prohibit their application in policy relevant measures. More elaborate techniques are under development. Then, different approaches are presented to exemplify how emissions from international aviation can be allo cated to national territories. For Switzerland an estimate based on the residence approach is explained in more detail. Finally, the paper elucidates the measures taken by the European Union to include the aviation sector into its emission trading scheme.