COSIS’ quest for climate justice: A brief history of the ITLOS advisory opinion

This article provides a brief history of the origins of the Commission of Small Island States on Climate Change and International Law (COSIS) and its request for an ITLOS advisory opinion. In doing so, it will position COSIS’ journey and the unanimous 2024 ITLOS Advisory Opinion in a broader context of climate justice. Against a backdrop of long-standing frustrations with the failings of the UNFCCC and Paris Agreement COP process to abate dangerous climate change and keep global warming below 1.5 °C, small island States are aware that existing obligations under international law already support their fundamental demands. They have thus taken the reins in a turn to international courts and tribunals in an attempt to level the playing field against major emitters. This brief history and case analysis will reflect on this historic move, discussing the relationship between the parallel proceedings before ITLOS and the ICJ, as well as the procedural and substantive significance of the 2024 ITLOS Advisory Opinion.