A study by Opportunity Green, commissioned by Transport and Environment.

This report draws on analysis of international law to detail the UK’s obligation to act on greenhouse gases (GHGs) from the international maritime sector, outside the framework of the International Maritime Organisation (IMO).

It determines that the Paris Agreement and the UN Convention on the Law of the Sea (UNCLOS) place a positive obligation on the UK to reduce maritime emissions. If the IMO enacts regulations that drive the required emissions reductions, then the UK would have no further obligation to act. But in the absence of action from the IMO in line with the Paris Agreement, that obligation is still with the signatory state.

Provided a number of important legal and enforcement considerations are respected and built into the design of any policy measure, there are numerous avenues through which the UK could take national action.