The maritime transport of freight and passengers is a crucial part of the global economy, but also a significant source of CO2 emissions. To make progress towards climate targets, countries need to monitor CO2 emissions from vessels operated by resident companies. However, since most shipping occurs beyond territorial waters, a consistent and comparable tracking of these emissions poses challenges to national statistical authorities.
The OECD’s experimental database offers a new source of monthly data for CO2 emissions from maritime transport. Emissions are estimated using a bottom-up approach consistent with the IMO Fourth GHG Study and are attributed to countries based on the vessel operators' economic residence (residence-based approach). In addition, a complementary approach extends the database by allocating emissions to the country from which voyages physically depart (port-of-departure-based approach).
This database supports both statistical measurement and environmental policymaking. On the statistical side, they bring granular and timely information that bridges two accounting frameworks of greenhouse gas emissions: the System of Environmental Economic Accounting (SEEA) and the United Nations Framework Convention for Climate Change. Moreover, it facilitates the compilation of Air Emission Accounts according to the SEEA. From an environmental policy perspective, the database helps monitor the effectiveness of new technologies and policy measures to curb maritime-related CO2 emissions.