The regulation of greenhouse gas emissions from international aviation and maritime transport has proved to be a difficult task for international climate negotiations such as the Paris Agreement in 2015. Almost two decades prior, Article 2.2 of the Kyoto Protocol excluded emissions from international aviation and maritime transport from its targets, delegating the negotiation of sector-specific regulations to the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO), respectively. However, progress at these venues has also been limited.