Validating rules and clarifying obligations through strategic sea level rise litigation

In recent years, there has been an observable emergence of a presumption of continuing statehood and of a rule of stability and permanence of coastal States’ baselines and maritime areas’ outer limits. Both the ‘emergent’ rules are aligned with the existing rules of general international law and of the law of the sea (as established in UNCLOS). However, there is tangible evidence in State practice, in scholarly works, and in the works of the International Law Association and the International Law Commission to support the emergence of these rules, which are being formed as a reaction to the threat posed by sea level rise to low-lying and small island States, the majority of them being developing, if not the least developed States, thus not responsible for historical greenhouse gasses emissions. In this framework, this article explores the dynamic nature of international law, which can accommodate the emergence of new rules, as evidenced by State practice, that challenge and defeat the existing treaty-based rules. This article also takes the view that the International Tribunal for the Law of the Sea and the International Court of Justice (ICJ) have the necessary institutional authority to validate the emergence of such rules, thus informing all participants in international law about the binding nature of the rules. In this context, this paper also analyses the outcomes of the ICJ advisory opinion on climate change in respect of sea level rise.