Intercontinental shipping in the European Union emissions trading system: A ‘fifty–fifty’ alignment with the law of the sea and international climate law?

The European Commission has proposed to extend the European Union (EU) emissions trading system to 50% of the carbon dioxide emissions from intercontinental maritime voyages that start or end at European ports. Yet, it remains unclear why this ‘fifty–fifty’ scope was selected and whether it is compatible with international law. This article disentangles the proposal's rationale and maps the EU's jurisdictional possibilities and limitations from the perspective of the law of the sea and international climate law. The findings suggest that, although there are sufficient jurisdictional grounds for implementing the extended emissions trading system as a port entry condition, the applicable legal limitations require certain amendments to the EU proposal. Concrete legal suggestions are formulated to increase alignment with the enforcement restrictions of the United Nations Convention on the Law of the Sea and with the principle of common but differentiated responsibilities and respective capabilities in international climate law, while complying with the obligations of nondiscrimination, good faith, and nonabuse of rights.