ICJ AO Litigation Notes Digest February 2026

This briefing, produced by a coalition of climate litigation practitioners, provides structured 'Litigation Notes' to help lawyers integrate the International Court of Justice's (ICJ) July 23, 2025, advisory opinion (AO) on States' climate obligations into legal cases. This specific note focuses on corporate conduct, detailing how the ICJ AO establishes State duties to regulate private actors, particularly in the fossil fuel industry, to prevent significant environmental harm.

• The ICJ AO establishes that States may breach international legal obligations if they fail to prevent significant harm to the climate system resulting from fossil fuel activities, specifically including production, consumption, licensing, and subsidizing.
• States are required to exercise 'stringent due diligence' to ensure private actors under their jurisdiction do not cause significant climate harm. This standard requires not only the adoption of rules but also vigilance in enforcement and administrative control, informed by the best available science, such as IPCC reports.
• The ICJ identified the primary temperature goal under the Paris Agreement as holding the global average temperature increase to below 1.5°C, which serves as a legal standard for emissions reduction plans.
• Under the Paris Agreement, Nationally Determined Contributions (NDCs) create binding legal obligations for States to act with due diligence in implementing domestic mitigation measures, including the regulation of private actors.
• States must account for cumulative environmental harm, as individually minor activities by various States and private actors can collectively result in significant damage to the environment.
• While climate change results from cumulative emissions, the ICJ notes it is scientifically possible to determine the total contribution of individual States to global emissions, considering both historical and current data.
• The ICJ AO asserts that the protection of the climate system is a prerequisite for the effective enjoyment of human rights, requiring States to adopt standards, legislation, and regulation of private actors.
• The polluter-pays principle from the Rio Declaration is not explicitly reflected in main climate treaties, but it may still apply through sector-specific treaties or national laws, such as strict liability for hazardous activities.

APA

Center for International Environmental Law (2026). ICJ AO Litigation Notes Digest February 2026. https://www.ciel.org/wp-content/uploads/2026/03/ICJ_AO_Litigation-Note-on-Corporate-Conduct_Feb2026.pdf

Chicago

Center for International Environmental Law. ICJ AO Litigation Notes Digest February 2026. 2026. https://www.ciel.org/wp-content/uploads/2026/03/ICJ_AO_Litigation-Note-on-Corporate-Conduct_Feb2026.pdf.

Wikipedia

{{cite report |author=Center for International Environmental Law |title=ICJ AO Litigation Notes Digest February 2026 |date=February 2026 |url=https://www.ciel.org/wp-content/uploads/2026/03/ICJ_AO_Litigation-Note-on-Corporate-Conduct_Feb2026.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{centerforinternationalenvironmentallaw2026icj, author = {{Center for International Environmental Law}}, title = {{ICJ AO Litigation Notes Digest February 2026}}, institution = {Center for International Environmental Law}, year = {2026}, month = feb, url = {https://www.ciel.org/wp-content/uploads/2026/03/ICJ_AO_Litigation-Note-on-Corporate-Conduct_Feb2026.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }