From Advisory Opinion to Global Mandate: The ICJ on Climate Change and the UN General Assembly’s Endorsement

On 20 May 2026 the United Nations General Assembly adopted a resolution welcoming the International Court of Justice’s advisory opinion on the Obligations of States in respect of Climate Change as an authoritative contribution to the clarification of existing international law. The vote — 141 in favour, 8 against and 28 abstentions — marks the moment at which the World Court’s most consequential environmental pronouncement moved from the Peace Palace into the political mainstream. For governments, regulators and businesses, including in India, the opinion is no longer an academic text; it is a reference point for policy, litigation and investment.

How the opinion came about

The request originated in a campaign led by law students in the Pacific and taken up by Vanuatu, culminating in General Assembly resolution 77/276 of March 2023. The Assembly asked the Court two questions: what obligations States have to protect the climate system from greenhouse-gas emissions, and what legal consequences follow where States, by their acts or omissions, cause significant harm to it. More than ninety States and organisations participated — the largest participation in the Court’s history — and India made written and oral submissions. The Court delivered its unanimous opinion on 23 July 2025.

What the Court said

Multiple sources of obligation. The Court held that States’ obligations derive not only from the climate treaties — the UN Framework Convention on Climate Change, the Kyoto Protocol and the Paris Agreement — but also from customary international law, international human rights law, the law of the sea and other environmental treaties. A State cannot escape its obligations simply by staying outside, or withdrawing from, a particular treaty.

A stringent standard of due diligence. The customary duty to prevent significant harm to the environment and the duty to cooperate apply to the climate system, and the standard of diligence is stringent given the gravity of the threat. Under the Paris Agreement, the 1.5°C limit has become the primary temperature goal, and nationally determined contributions must reflect each party’s highest possible ambition; the discretion States enjoy in setting them is not unlimited.

Fossil fuels. The Court indicated that a State’s failure to take appropriate action to protect the climate system — including through fossil-fuel production, consumption, the grant of exploration licences or the provision of subsidies — may constitute an internationally wrongful act attributable to it.

Obligations owed to all. The relevant obligations are owed erga omnes (to the international community as a whole) or, within the treaties, erga omnes partes, so that any State may invoke responsibility for their breach.

Consequences of breach. Where a breach is established, the ordinary consequences of State responsibility apply: cessation, assurances of non-repetition where appropriate, and full reparation — restitution, compensation or satisfaction — subject to proof of a sufficient causal link between the wrongful act and the injury.

Sea-level rise. The Court addressed the anxieties of low-lying island States, indicating that baselines and maritime zones need not be redrawn as coastlines recede and that the disappearance of territory does not by itself extinguish statehood.

Equity and differentiated responsibility

For India, one of the most important features of the opinion is its treatment of the principle of common but differentiated responsibilities and respective capabilities, in light of different national circumstances. The Court confirmed that this principle informs the interpretation of all the relevant obligations. Historical responsibility for cumulative emissions, levels of development and capacity therefore remain relevant in assessing what due diligence requires of a particular State. This was a central theme of India’s submissions, which stressed equity and the developmental needs of the Global South.

The opinion is thus not a one-size-fits-all mandate. It does, however, make clear that every State — developed or developing — must act, and must be able to demonstrate that its policies are a genuine, good-faith effort commensurate with its capabilities.

The General Assembly resolution

Resolution A/80/L.65, tabled by Vanuatu with some ninety co-sponsors, welcomes the opinion, calls on all States to comply with the obligations the Court identified, recalls the legal consequences of breach, and affirms the continuity of statehood in the face of sea-level rise. It also requests the Secretary-General to report, in consultation with Member States, on ways to advance compliance and on possible gaps in multilateral efforts to address climate harm. Earlier proposals for an international register of damage and a reparations mechanism did not survive into the final text, but the report opens a pathway to further action.

Eight States voted against: Belarus, Iran, Israel, Liberia, the Russian Federation, Saudi Arabia, the United States and Yemen. Amendments proposed by a group led by Saudi Arabia were rejected.

What it means in India

Advisory opinions are not binding judgments, but they carry great weight as statements of existing law, and national courts increasingly rely on them. India’s Supreme Court has already recognised, in M.K. Ranjitsinh v. Union of India (2024), a right to be free from the adverse effects of climate change, grounded in Articles 14 and 21 of the Constitution. The ICJ’s reasoning on due diligence and human rights is likely to be cited in future public interest litigation concerning environmental clearances, coal and mining approvals, coastal regulation and urban heat.

For businesses, the practical implications include:

• Regulatory direction. Climate measures — the carbon credit trading scheme, energy-efficiency norms and sectoral targets — rest on firmer legal foundations and are more likely to tighten than relax.
• Disclosure and governance. Listed companies already report under SEBI’s Business Responsibility and Sustainability Reporting framework; boards should expect closer scrutiny of transition plans and climate risk.
• Cross-border trade. Instruments such as the EU’s Carbon Border Adjustment Mechanism are likely to be defended by reference to the opinion, affecting Indian exporters of steel, aluminium, cement and fertilisers.
• Contracts and projects. Infrastructure and energy contracts should anticipate changes in law, permitting risk and climate-related disputes.

Conclusion

The ICJ has done what courts do best: it has translated a scientific and political emergency into the language of obligation and responsibility. The General Assembly’s endorsement gives that language political force. The task now is implementation — in national policy, in courtrooms and in boardrooms — in a manner that is both ambitious and fair.

References

• ASIL — UN General Assembly adopts resolution welcoming ICJ climate change advisory opinion
• EJIL: Talk! — From opinion to action
• UN News — General Assembly backs historic World Court climate crisis ruling
• International Court of Justice — Judgments, Advisory Opinions and Orders