Transforming international maritime law through the environmentalization of UNCLOS interpretation in the Anthropocene era

Abstract

This article examines the transformation of international maritime law in the context of the Anthropocene through the lens of the “environmentalization” of the interpretation of the United Nations Convention on the Law of the Sea (UNCLOS). The study proceeds from the premise that the contemporary climate crisis is systemic and transboundary in nature and directly affects the legal regulation of the use, protection, and preservation of the World Ocean. It argues that UNCLOS, drafted under assumptions of relative environmental stability, requires a dynamic and evolutionary interpretation in light of emerging ecological challenges, including anthropogenic greenhouse gas emissions, sea-level rise, ocean acidification, and the degradation of marine ecosystems.

Particular attention is devoted to the principle of systemic integration, as enshrined in Article 31(3)(c) of the Vienna Convention on the Law of Treaties (1969), which is analysed as a key interpretative tool for overcoming the fragmentation of international law and for coordinating UNCLOS with other relevant legal regimes, notably international climate law and international human rights law. The article explores the growing role of systemic integration in the jurisprudence of international courts and tribunals.

A central focus is placed on the Advisory Opinion of the International Tribunal for the Law of the Sea (ITLOS) in Case No. 31 of 21 May 2024, in which anthropogenic greenhouse gas emissions were qualified as marine pollution within the meaning of UNCLOS. The article assesses the significance of this finding for the articulation of a stringent due diligence standard and for the progressive development of the law of international responsibility in the context of climate change.

The study further analyses the Advisory Opinion of the International Court of Justice concerning States’ obligations in respect of climate change, in which the Court affirmed the existence of treaty-based and customary obligations to protect the climate system and recognized their erga omnes character. The article concludes that the environmentalization of UNCLOS interpretation is not optional but constitutes a necessary evolutionary pathway for adapting international maritime law to the existential challenges of the Anthropocene and for strengthening the legal protection of the ocean as a global common good.