Obligations of States to Protect Climate: Advisory Opinion of the International Court of Justice

The article analyzes the Advisory Opinion of the International Court of Justice on the International Legal Obligations of States to Protect the Climate, adopted in July 2025. The article examines the main findings and rationale for this opinion and substantiates its practical implications. It is concluded that, based on the approaches applied by the Court, climate protection practice will actively develop at all levels on the basis of numerous sources of both treaty‑legal and customary‑legal nature, using an impressive set of interpretive guidelines, including systemic integration, as well as taking into account the decisions of the Conference of the Parties to the UN Framework Convention on Climate Change and the latest climate science data reflected in the reports of the Intergovernmental Panel on Climate Change. The International Court of Justice essentially confirmed the procedural possibilities for initiating and resolving in the appropriate international instances both inter‑state “horizontal” disputes regarding the violation of climate obligations of some states towards others, and “vertical” disputes between private individuals and states regarding the latter’s violation of human climate rights. The Court formulated general standards by which international instances, as well as national and regional law enforcement bodies, can be guided when resolving specific disputes, including in establishing the content of international climate obligations, identifying their violations, and determining the legal consequences of the identified violations. Paragraph 427 of the Advisory Opinion shows signs of an emerging and far‑reaching presumption of illegality regarding states’ activities in the financing, exploration, development and consumption of fossil fuels. This indicates that the advisory opinion of the UN International Court of Justice and the joint declaration of two judges adopted simultaneously with it are becoming further major elements of the regulatory puzzle that forms the basis of the actively and progressively promoted scenario of a green energy revolution in the world, which presupposes an accelerated transition — by 2050 — from fossil fuels to renewable energy sources.