The International Court of Justice (ICJ) interpreted international climate law and defended also climate migrants.
In an absolutely crucial advisory opinion of 23 July 2025, the International Court of Justice interpreted (ICJ) in 132 pages the obligations of states to protect the climate, based on a number of international treaties and commitments. The Court also stood up for climate migrants.
In particular, the ICJ, as the United Nations’ highest legal authority on public international law, has held that climate change treaties impose binding obligations on States Parties to ensure the protection of the climate system and other components of the environment from anthropogenic emissions of greenhouse gases. ICJ then listed a number of climate and other conventions from which this obligation to protect the climate arises, i.e. not only the Paris Convention, but also the Framework Convention on Climate Change, the Kyoto Protocol, the UN Convention on the Law of the Sea, the Convention on Biological Diversity and others, and referred as well to the binding customary international law (the obligation to prevent significant harm to the environment and the obligation to cooperate in preventing climate damage). Thus, even withdrawal from the Paris Convention, on which, among other things, the EU Climate Law (Regulation (EU) 2021/1119) and its successor legislation, known as the Green Deal, is based, does not relieve the State of its obligation to ensure climate protection and to ensure that it does not cause substantial harm to the climate system and the environment.
The Court has also held that conditions resulting from climate change that may threaten the lives of individuals may lead them to seek safety in another country or prevent them from returning to their own country. In the Court’s view, States have obligations under the principle of non-refoulement where there are substantial grounds for believing that there is a real risk of irreparable harm to the right to life, contrary to Article 6 of the International Covenant on Civil and Political Rights, if individuals are returned to their country of origin (see Human Rights Committee, Teitiota v. New Zealand, 24 October 2019.
The ICJ’s findings will be a very important tool for lawyers and courts in so-called climate litigation lawsuits, which are often the only means of forcing the state and large corporations to take greater action on climate change.