UN urges States to adopt ICJ's 2025 advisory opinion on climate change obligations

On 20 May 2026, the UN General Assembly passed a resolution urging States to adopt the International Court of Justice's (ICJ) 2025 advisory opinion on climate change obligations into their national policy and to commit to follow-up action. 

When the ICJ’s advisory opinion in July 2025 found that States have binding legal obligations under international law to address climate change and protect the environment, the decision was described as a significant step with the new UN resolution giving that ruling political momentum. 

For more detail on the ICJ's advisory opinion itself, see our previous blog post.

The UN resolution

The resolution calls on all UN Member States to comply with their respective obligations under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic greenhouse gas emissions, as identified by the ICJ. 

Specifically, the resolution identifies three categories of obligation:

• preventing significant harm to the environment by acting with due diligence, using all means at their disposal and recognising that the standard of due diligence is stringent; 

• cooperating with each other in good faith in sustained and continuous forms of cooperation to prevent significant harm; and 

• respecting and ensuring the effective enjoyment of human rights by taking the necessary protective measures.

The resolution also calls upon all parties to the Paris Agreement to comply with their treaty obligations, in accordance with their common but differentiated responsibilities and respective capabilities, in the light of different national circumstances. It urges States to implement measures to achieve the collective temperature goal of 1.5°C above pre-industrial levels, including by tripling renewable energy capacity and doubling energy efficiency improvements by 2030, transitioning away from fossil fuels in a just, orderly and equitable manner so as to reach net zero by 2050, and phasing out inefficient fossil fuel subsidies as soon as possible. 

Vanuatu, a Pacific island nation on the frontline of the climate crisis, drew up the resolution with more than 60 countries co-sponsoring it. It was adopted on 20 May 2026 following extensive negotiations and several rounds of proposed amendments. The final vote was 141 in favour, 8 against and 28 abstentions, with Belarus, Iran, Israel, Liberia, Russia, Saudi Arabia, the United States and Yemen voting against.

The States that had championed the resolution had sought the creation of a dedicated mechanism to register losses and compensation claims arising from climate-related harm. However, these proposals were rejected during the negotiations. The Secretary-General's mandate was confined to submitting a report on ways to advance compliance with ICJ’s findings, expressly without prejudice to the legal positions of States and without implying any determination of responsibility. Those same States succeeded in resisting a series of proposed amendments that would have considerably narrowed the resolution's scope.

Why this matters 

As we set out in detail in our previous blog post, while the ICJ's opinion is not legally binding, it does provide an authoritative interpretation of legally binding obligations and carries substantial legal and moral weight. As a result, it may well influence States' climate change policies, including in relation to carbon-intensive sectors. 

Several implications are worth highlighting:

• Regulatory risk. There is now an increasing international political pressure on States to reflect the ICJ's findings in domestic policy and legislation. Businesses, particularly those in carbon-intensive sectors, should monitor any new regulatory requirements and keep a close eye on increased scrutiny of climate-related conduct in the jurisdictions where they operate.

• Energy sector implications. As noted previously, the ICJ found that failures of a State to take appropriate action to protect the climate system from GHG emissions, including through fossil fuel production or consumption, granting of fossil fuel exploration licences, providing fossil fuel subsidies, or failures to take necessary regulatory and legislative measures, may constitute an internationally wrongful act attributable to that State. 

• Climate litigation. It is likely that the opinion will be used as building blocks for future climate litigation, in particular in domestic litigation challenging a State's progress towards its international obligations. Although ICJ advisory opinions are not binding, they carry significant legal and moral authority, helping to clarify and develop international law by defining States' legal obligations.

• Consequences of breach. The ICJ has confirmed that if States breach their obligations, they are legally responsible and may be required to stop the wrongful conduct and may be required to provide credible assurances of future compliance and to make full reparation for harm caused. 

What's next?

The UN Secretary-General is expected to present a report in September 2027 on how States might practically achieve compliance with the ICJ's ruling. That report is to be prepared in consultation with Member States and expressly without prejudice to States’ legal positions and without implying any determination of responsibility. 

The General Assembly has also decided to include a dedicated follow-up item to the advisory opinion on the agenda of its 83^rd session (2028–29). 

Both steps have the potential to serve as a significant driver of domestic legislative activity and could set the terms for how compliance is assessed and measured across signatory States, particularly in jurisdictions where climate regulation is already advancing. 

We will continue to monitor developments in this area. In the meantime, clients operating in regulated sectors, in international markets, or in industries with significant carbon footprints should consider reviewing their climate-related risk exposure and assessing how emerging regulatory frameworks may affect their operations.