Taking the current when it serves: Prospects and challenges for an ITLOS advisory opinion on oceans and climate change

Abstract The 2021 Agreement for the Establishment of the Commission of Small Island States on Climate Change and International Law has brought the prospect of an advisory opinion on climate change from the International Tribunal for the Law of the Sea (ITLOS) a step closer to reality. The Agreement authorizes COSIS to submit a request to the full Tribunal, following the road paved for the first time—and not uncontroversially—by the 2015 ITLOS Sub‐regional Fisheries Commission Advisory Opinion. This article explores the potential for progressive development of ( erga omnes ) obligations under the law of the sea in relation to climate change by means of an advisory opinion, as well as challenges that may be encountered. Drawing on previous case law, it reflects on the suitability of the ITLOS advisory route, substantive and strategic considerations and potential future implications of an ITLOS advisory opinion on climate change.