PRESS RELEASE

by Marangopoulos Foundation for Human Rights

“The most important case of our time”: Climate change before the International Court of Justice and human rights

On July 23, 2025, the International Court of Justice (ICJ or the ‘Court’) issued its long-awaited Advisory Opinion on Obligations of States in Respect of Climate Change. This historic advisory opinion was issued following a request from the United Nations General Assembly and confirms the decisive role of international law in addressing the climate crisis, as well as the interplay of general international law with climate change treaties.

Specifically, the Court was called upon to answer two questions posed by the General Assembly: first, 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; second, 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 other States, as well as to peoples and individuals.

As far as the obligations of States are concerned, the Court ruled in principle that these arise from the entire body of international law. Special emphasis was placed on climate change treaties, namely the United Nations Framework Convention on Climate Change, the Kyoto Protocol and the Paris Agreement. Specifically, the Court made it clear that climate change treaties contain binding obligations to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of greenhouse gases, and explicitly referred to the content of these instruments, characterising them as the most directly relevant applicable law (para. 121).

Nonetheless, the Court clarified that binding obligations for States do not arise solely from international climate change treaties, but also from customary international law, according to which States have a duty to prevent significant harm to the environment by acting with due diligence, as well as a duty to co-operate with each other. Similarly, obligations arise from environmental agreements, from the United Nations Convention on the Law of the Sea -as evidenced by the Advisory Opinion of the 21^st of May 2024 of the International Tribunal for the Law of the Sea- as well as international human rights law, which dictates that States must respect and ensure the effective enjoyment of human rights.

With regard to the legal consequences of breaches of obligations by States, the Court ruled that the breach of any obligation constitutes an internationally wrongful act entailing the international responsibility of the State. The Court clarified that the legal framework for the international responsibility of a State is the customary rules of international responsibility, while explaining that the legal consequences depend on the specific breach and the damage caused, which means that an in concreto assessment is required. The Court concluded that States responsible for internationally wrongful acts relating to climate change are required not only to cease the internationally wrongful acts and provide assurances and guarantees of non-repetition, but also to provide full reparation in the form of restitution, compensation and/or satisfaction.

The Marangopoulos Foundation for Human Rights (MFHR) considers it necessary to shed light on the Court’s findings regarding the inextricable link between climate and environmental protection and the enjoyment of human rights. Specifically, the Court ruled that the negative effects of climate change can significantly limit the enjoyment of human rights, such as the right to life, the right to health, and the right to an adequate standard of living, including access to water, food, and housing (para. 377 et seq.). Furthermore, the Court did not hesitate to describe the right to a clean, healthy, and sustainable environment as a necessary precondition for the enjoyment of human rights and to emphasise that this right derives from the interdependence between human rights and the protection of the environment (para. 393).

It is worth noting that the Court emphasised that States have obligations arising from the principle of non-refoulement towards individuals who face a real risk of irreparable harm to life (para. 373). Furthermore, the Court placed particular emphasis on groups of people who are particularly vulnerable to climate change and its effects, such as children, women, and indigenous peoples (para. 383 et seq.).

Finally, the Court reaffirmed the extraterritorial application of human rights treaties (para. 394 et seq.) and concluded that international human rights law, climate change treaties, and environmental agreements “inform each other”

(para. 404), making it necessary for States to take all of them into account when implementing their obligations.

The Advisory Opinion of the ICJ follows with equal courage the path laid out by other international courts and tribunals regarding the issue of the relationship between climate change and the enjoyment of human rights. A notable example is the case of Verein Klimaseniorinnen Schweiz and Others v. Switzerland, which was issued on April 9, 2024, where the European Court of Human Rights (ECtHR) ruled for the first time that the damages resulting from climate change jeopardize the enjoyment of human rights and may constitute violations of the European Convention on Human Rights (ECHR). Specifically, according to the ECtHR, climate change constitutes a clear and direct danger for health and thus for life, including private life.

In the same vein, the Inter-American Court of Human Rights (IACHR) issued its Advisory Opinion on Climate Emergency and Human Rights on July 3, 2025. Precisely, the IACHR ruled that climate change constitutes an emergency for the enjoyment of human rights, particularly with regard to the right to life and personal integrity, the right to health, food, water, shelter, and education, private and family life, property and housing, and the right to enjoy a healthy environment. The IACHR also recognised the disproportionate impact of climate change on vulnerable groups of people and confirmed the need for a holistic approach based on general international law, international environmental law, the law of the sea, and ultimately international human rights law.

The ICJ’s advisory opinion constitutes the culmination of all the other important advisory opinions and judgments of international courts and tribunals regarding the climate system, following a holistic approach and sounding the alarm for States and the international community, so that they finally realise that taking drastic and effective measures to address and mitigate climate change, as well as co-operating on an international level, are imperative for the preservation of life on Earth.

The Press Release by MFHR is also available in pdf format here.