(1287) Cameron Hepburn and Benito Müller Greenhouse gas emissions from international aviation services have been increasing rapidly and are likely to continue to do so in the absence of major policy changes. At the same time, while all countries will experience impacts from climate change, developing countries are the most vulnerable. Significant financial assistance for adaptation is therefore needed for developing countries, but current proposals are inadequate. Solutions to the challenges of both aviation greenhouse gas emissions and climate change adaptation finance are thus urgently required. This paper proposes an international air travel adaptation levy that addresses both problems.