How to address aviation's full climate impact best from an economic point of view? - AviClim project overview and update on first results

International aviation is a substantial emitter of CO2 and additionally contributes to climate change by short-lived non-CO2 effects, such as emission of NOX or triggered contrails and con-trail cirrus (e.g., Sausen et al., 2005): In 2005, aircraft-induced CO2 contributed 1.6% to the total anthropogenic radiative forcing (RF). If the non-CO2 climate effects are also considered, avia-tion’s contribution to total RF is about three times as large, i.e., 4.9% (Lee et al., 2009). Whilst international aviation’s CO2 emissions are regulated in a number of countries by market-based measures, this is not the case for most of aviation’s non-CO2 climate impacts. The interdisciplinary research project AviClim (Including Aviation in International Protocols for Climate Protection) explores the feasibility for including aviation’s CO2 and non-CO2 climate impacts (aviation-induced clouds, NOX emissions, water vapour emissions, sulphur emissions, etc.) in international protocols for climate protection. In addition, the associated economic im-pacts are studied. From an economic point of view, the implementation of a charge or an emis-sions trading scheme for selected non-CO2-gases and substances could be considered among oth-er options. Also, operational measures such as climate optimized flight-paths could be a viable option. The economic and environmental impacts of introducing selected reduction measures will be investigated by employing a DLR-developed simulation model. This paper is an updated version of Scheelhaase et al. (2012). It provides an overview of the AviClim research project and presents an update on the first results