The Advisory Opinions’ Remarkable Significance for International Law

Abstract The remarkable significance of the advisory opinions of the International Court of Justice (ICJ) and the International Tribunal for the Law of the Sea (ITLOS) in relation to climate change obligations is evidenced by many factors. This introductory article to a Special Issue on the advisory opinions situates scholarly discussions about the convergence between international courts and tribunals, the use of science in adjudication, the legal consequences of obligations erga omnes, and the impact of the advisory opinions. It argues that the advisory opinions demonstrate unprecedented levels of participation in judicial proceedings (as prompted by small island developing states), systemic integration of the law and notable legal effects, including a positive, action-oriented reception by the United Nations General Assembly. Although non-binding, the advisory opinions are likely to guide domestic, regional, and international responses of states and other actors to ensure protection of the climate system.