Fourth IMO Greenhouse Gas Study 2020
The IMO's 2020 inventory of shipping greenhouse gas emissions, its methods, and the operating-speed data derived from it.
The Fourth IMO Greenhouse Gas Study 2020 is the IMO’s periodic inventory of greenhouse gas emissions from international shipping, estimating emissions by ship type and size and projecting future trajectories under a range of economic scenarios. It is the analytical basis on which subsequent IMO policy debate, including the 2023 GHG Strategy, has rested.
Beyond the headline inventory, the study is a widely used source of fleet operating data, including average operating speeds by ship type and size derived from AIS observation. That dataset has a direct commercial afterlife: RightShip states the common speed used in the speed-corrected GHG Rating methodology is referenced from the study, with a 10 percent reduction applied to allow for fleet slowdown attributable to EEXI power limitation.
The full article will cover the study’s scope and method, the bottom-up and top-down estimation approaches, the treatment of methane and nitrous oxide alongside CO2, the carbon intensity findings, the projection scenarios, and the study’s use as a data source in commercial and regulatory instruments.