Difficulties and responses in applying the principle of common but differentiated responsibilities to carbon emission reduction in high seas fisheries

Carbon emissions from high-sea fisheries remain insufficiently addressed, with no unified international framework currently established to regulate and reduce these emissions. Given this, clarifying how carbon reduction responsibilities should be divided among states through appropriate normative principles is a prerequisite for collective international action. The principle of common but differentiated responsibilities (CBDR) offers useful guidance for the dividing up mitigation obligations fairly and has become a fundamental principle of global climate governance. However, whether it applies to carbon emissions reduction in high-sea fisheries remains uncertain. Examining where the CBDR principle came from and how it has developed gives us a solid basis for its application in this field. First, carbon emissions from high-sea fisheries create climate change risks that affect all states, which points to shared responsibility for mitigation under the principle of international cooperation. Second, developed countries’ historical responsibility for high-sea fishery emissions, along with developing countries’ relatively limited financial and technological capacities and the legal foundations established under the law of the sea, together justify differentiated mitigation responsibilities among states. Nevertheless, applying the CBDR principle to high-sea fisheries runs into several practical challenges, including selecting an appropriate implementation pathway, identifying responsible actors, and determining differentiated obligations. To address these challenges, this study proposes several recommendations, including better coordination between the climate change regime and the high-sea fisheries governance framework, factoring catch volume into the criteria for allocating mitigation responsibilities, and strengthening financial mechanisms to support developing countries in reducing carbon emissions from high-sea fisheries.