The inclusion of international aviation and shipping emissions in a global climate policy framework has proved to be a difficult issue. Notwithstanding discussing the subject for over a decade, Annex I countries have not been successful in limiting or reducing greenhouse gas emissions from international transport. As the IMO is considering greenhouse gas mitigation options and simultaneously the UNFCCC is engaging in several processes to define long-term cooperative action for all and further commitments for Annex I parties, the issue of bunker fuels is again attracting attention. This paper sets out to identify the conditions for progress on this issue. It also evaluates two basic architectures for climate policy for shipping and broaldy assesses the impacts for developing countries. The report shows that climate policy for international transport can be organised in two ways, either in the UNFCCC or in IMO and ICAO. In the former case, responsibilities for emissions have to be differentiated according to the route of vessels. In the latter case, revenues of financial instruments could be used to fund adaptation in developing countries. The report shows that in either case, economic impacts on developing countries would be modest if the policies were properly designed.