Decarbonisation represents a top priority in the agenda of the shipping industry. Governments, regional and international organisations are currently engaged in adopting effective measures to reduce the impact of shipping while ensuring their suitability for maritime trade operators. Since the nineteenth century, shipping has been characterised by attempts of harmonisation drafted by international commercial bodies, such as the Comité Maritime International (CMI), focused on the unification of maritime and commercial laws. In modern times, the role of governments became more prominent, as the development of scientific knowledge and the increasing involvement of civil society called for greater regulation at the public level. Oil pollution incidents, such as the Torrey Canyon (1967), the Exxon Valdez (1989), the Erika (1999), and the Prestige (2002) demonstrated the importance of public control over commercial activities carried out by sea. In contrast to other sources of marine pollution, such as oil spills and land-based contamination, atmospheric pollution and greenhouse gas (GHG) emissions are relatively young sources. The 1982 United Nations Convention on the Law of the Sea (UNCLOS) was one of the first treaties to recognise their impact on the marine environment, and now they represent a major challenge faced by the shipping industry. The International Maritime Organization (IMO) is tasked with implementing the GHG agenda but is considered largely ineffective and other regional entities, particularly the EU, have taken the lead.