Request for an advisory opinion on the obligations of States with respect to climate change

On March 29, 2023, the 77th session of the United Nations General Assembly (UNGA) adopted the resolution A/77/L.58, requesting an advisory opinion from the International Court of Justice (ICJ) on the obligations of States with respect to climate change. The resolution was adopted by consensus. This initiative was largely led by the Government of Vanuatu, which worked with other countries to prepare a draft resolution through internal negotiations and several rounds of informal consultations with the wider UN membership. The request for an advisory opinion acknowledges that “climate change is an unprecedented challenge of civilizational proportions and that the well-being of present and future generations of humankind depends on our immediate and urgent response to it”. The UNGA resolution also takes note of the scientific consensus expressed, inter alia, in the reports of the Intergovernmental Panel on Climate Change. In particular, the UNGA underscores that anthropogenic emissions of greenhouse gases are “the dominant cause of the global warming observed since the mid-20th century” and that human-induced climate change “has caused widespread adverse impacts and related losses and damages to nature and people.” In this context, the UNGA recalls the importance of the United Nations Framework Convention on Climate Change and the Paris Agreement “as expressions of the determination to address decisively the threat posed by climate change”. The resolution also underscores the importance of implementing these treaties, particularly in light of the significant gap between States’ current nationally determined contributions and the emission reductions required to hold the increase in the global average temperature to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C, as well as the gap between current levels of adaptation and the levels needed to respond to the adverse effects of climate change. Therefore, in accordance with Article 96 of the Charter of the United Nations, the UNGA requests the ICJ to render an advisory opinion on the following questions: “Having particular regard to the Charter of the United Nations, the International Covenant on Civil and Political Rights, the International Covenant on Economic, Social and Cultural Rights, the United Nations Framework Convention on Climate Change, the Paris Agreement, the United Nations Convention on the Law of the Sea, the duty of due diligence, the rights recognized in the Universal Declaration of Human Rights, the principle of prevention of significant harm to the environment and the duty to protect and preserve the marine environment, (a) What are the obligations of States under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of greenhouse gases for States and for present and future generations; (b) What are the legal consequences under these obligations for States where they, by their acts and omissions, have caused significant harm to the climate system and other parts of the environment, with respect to: (i) States, including, in particular, small island developing States, which due to their geographical circumstances and level of development, are injured or specially affected by or are particularly vulnerable to the adverse effects of climate change? (ii) Peoples and individuals of the present and future generations affected by the adverse effects of climate change?” On April 12, 2023, the request for an advisory opinion was transmitted to the Court by the Secretary-General of the United Nations. Presentations of written statements were due on March 22, 2024. The ICJ received 91 written statements. Written comments were submitted on August 15, 2024. The ICJ received 62 written comments. The public hearings were held in December 2024. On July 23, 2025, the ICJ delivered the advisory opinion. The Court found that States are obligated to protect the climate system and other parts of the environment from anthropogenic GHG emissions, based on multiple legal sources including the UN Charter, climate treaties (UNFCCC, Kyoto Protocol, Paris Agreement), customary international law, environmental treaties, and international human rights law. These obligations include mitigation, adaptation, and cooperation duties, guided by principles such as sustainable development, precaution, and intergenerational equity. The Court affirmed that the duty to prevent significant harm and the duty to cooperate apply to all States, with due diligence as the governing standard. It also concluded that when States breach these obligations, they incur legal consequences under the customary international law of State responsibility, including duties to cease the harmful conduct, guarantee non-repetition, and provide reparation. The opinion emphasized that obligations related to climate protection are owed erga omnes and apply equally to harm caused to other States, vulnerable populations, and future generations.