In 2012, aviation was included in the EU ETS. In 2016, the ICAO also adopted a global measure to limit ⁠CO2⁠ emissions from international aviation (⁠CORSIA⁠). The aim of the research project is to investigate the reciprocal effects between these two market-based instruments. In particular, several options how both could be optimally combined are considered. In addition, the extent to which the two instruments are likely to contribute to achieving the EU climate protection targets for 2030 is quantified. Furthermore, the MRV cycles of both instruments and their differences are presented, the effect of a changed threshold value for participation in the EU ETS is analyzed and the possible role of an innovation fund for aviation is examined.