Since 1997 the International Maritime Organization, the United Nations agency responsible for the regulation of the international shipping sector, has been developing rules for the reduction of the sector’s greenhouse gas emissions. Significant difficulties have, however, emerged in the creation of appropriate economic instruments for reducing its greenhouse gas emissions, bringing to the forefront the application of the principle of common but differentiated responsibilities and respective capabilities (“CBBDRC”). A key principle within international climate change law, CBDDRC allows developing States, least developed States and the most environmentally vulnerable to be differentially treated based on their special situation and needs. Developing States, within the International Maritime Organization, rely on this principle in questioning the appropriateness of application of uniform international shipping standards to the greenhouse economic instruments currently in development, viewing this uniformity as economically disadvantageous to them. Developed State members, on the other hand, maintain the traditional view that all of the Organization’s instruments, including those for the reduction of ship-source greenhouse gas emissions, must have uniform application to all States. This article addresses the difficulties that have arisen in creating economic instruments for the reduction of the international shipping sector’s greenhouse gas emissions and highlights the significant compatibility issues between the work of the International Maritime Organization and international climate change law. By providing a contemporary analysis of the international law principle of CBDDRC and its application to the international shipping sector it is argued that the International Maritime Organization cannot currently attain the synthesis necessary to effectively apply the CBDDRC principle. The article advocates that further work is needed in identifying the legal content of the CBDDRC principle and its constituent elements that are necessary before States can effectively negotiate the formation of a differential layer of responsibilities for developing States.