This research project serves two main objectives: 1- to inform political decisionmakers about the environmental, political and socio-economic implications for Belgium of integrating the international aviation transport sector into climate policy; 2- to help with the preparation and assessment of Belgian climate policy, on the context of the negotiations concerning the expansion of the European Emission Trading Scheme (EU-ETS) and the post-2012 phase at the UNFCCC level. The whole project covers the evolution of the climate policy and the analysis of policy options to tackle aviation total climate impacts, the creation of an emission database for Belgium and a new emission calculator tool (Aviactor), a better understanding of non-CO2 aviation climate impacts and metrics through the integration of a specific module in the general climate model JCM5 and the use of regional climate modelling, a multi-criteria analysis (MCA) to synthesize several characteristics of selected policy options, as well as some considerations about total climate impacts from the international maritime transport.