Members of the International Court of Justice. Photograph: UN Photo/ICJ-CIJ/Frank van Beek. Courtesy of the ICJ. All rights reserved.

ON SOURCE: WE DON'T HAVE TIME

The End of Excuses: What the ICJ Opinion Means for Climate Accountability

In a seismic shift for global climate justice, the International Court of Justice (ICJ) has issued an advisory opinion stating that governments have binding legal obligations to combat climate change and could be held legally responsible for the damage their emissions cause to other nations.

A long fight led by small nations in peril

In its unanimous opinion, the ICJ found that states must act to protect the climate system and the environment not only under the framework of global treaties like the Paris Agreement but also under customary international law and international human rights law. The ruling affirms that failure to do so may constitute an 'internationally wrongful act,' opening the door for affected countries to pursue legal action against those responsible.

The case was brought by Vanuatu, a low-lying Pacific island state severely threatened by rising seas and extreme weather, and backed by more than 130 countries. BBC Earth recounts the remarkable story of how, in 2019, a group of Pacific Island law students proposed the idea and successfully persuaded their government to bring the matter before the United Nations. In March 2023, the UN General Assembly adopted a resolution requesting the Court’s opinion.

Climate action as a duty

At the heart of the Court’s opinion is the finding that states have obligations arising from a broad range of legal sources—including the United Nations Framework Convention on Climate Change (UNFCCC), the Paris Agreement, the UN Convention on the Law of the Sea, the Convention on Biological Diversity, and customary international law. These duties include:

• Reducing greenhouse gas emissions;
• Preparing and updating national climate plans aligned with the 1.5°C warming target;
• Cooperating internationally and acting with due diligence;
• Regulating the actions of private entities under their jurisdiction.

The Court also stated that high-emitting states’ continued support for fossil fuel exploration, production, and subsidies could breach these legal duties. According to the ICJ press release on the opinion, “States have a duty to prevent significant harm to the environment by acting with due diligence and to use all means at their disposal to prevent activities carried out within their jurisdiction or control from causing significant harm to the climate system.”

A legal foothold for international accountability

While ICJ advisory opinions are not legally binding, they are considered highly authoritative interpretations of international law and are often referenced by national and international courts, as well as during UN negotiations. Ralph Regenvanu, Vanuatu’s Minister of Climate Change, explained the significance of this development to small island nations: “This ruling provides a critical foundation for lawyers and activists to further strengthen and affirm that climate destruction is against the law.”

The ICJ joins a growing wave of international legal bodies stepping into the climate arena. In May 2024, the International Tribunal for the Law of the Sea (ITLOS) ruled that greenhouse gas emissions count as marine pollution, and in July 2025, the Inter-American Court of Human Rights declared for the first time that people have a right to a healthy climate.

The ICJ opinion designates climate change “an existential problem of planetary proportions that imperils all forms of life and the very health of our planet.” It goes on to conclude that this global threat must be addressed by more than legal proceedings: “International law… has an important but ultimately limited role in resolving this problem. A complete solution to this daunting, and self-inflicted, problem requires the contribution of all fields of human knowledge.”

Ralph Regenvanu (left) sits with other Representatives of Vanuatu and the Melanesian Spearhead Group. Photograph: UN Photo/ICJ-CIJ/Frank van Beek. Courtesy of the ICJ. All rights reserved.

Can the ICJ bring the U.S. back to the table?

One open question remaining is what implications this ruling might have for the United States as it abandons climate commitments and expands fossil fuel production. Although President Trump has initiated the process of withdrawing the U.S. from the Paris agreement, the ICJ opinion confirms that states have legal obligations under international law to prevent climate harm and repair damage, regardless of their participation in specific treaties.

For Minister Regenvanu, the opinion is a direct challenge to powerful nations that have long evaded accountability. “Major polluters—past and present—cannot continue to act with impunity and treat developing countries as sacrifice zones,” he said. 'We will now take the ICJ ruling back to the United Nations General Assembly, and pursue a resolution that will support implementation of this decision.'

U.S. climate advocates see the opinion as lending support to their cause. Julia Olson, Executive Director of Our Children’s Trust said the ruling reinforces constitutional claims in youth-led lawsuits like Lighthiser v. Trump, and makes clear that governments have a legal duty to act. “No government has the right to sacrifice the lives of children to sustain a fossil fuel economy,” she said. “Protecting the rights of young people is not optional—it’s a legal obligation.”

For the U.S. and other high-emitting countries, the Court’s opinion leaves little doubt: ignoring the climate crisis is no longer just bad policy—it may be unlawful. More broadly, this ruling signals a turning point in global climate governance, offering a powerful legal foundation to compel decisive action from countries that have delayed or resisted meaningful emissions cuts. With it, we are entering a new era where climate justice is no longer merely aspirational, but enforceable.

Written by Weston Wilson for We Don't Have Time

ON SOURCE: WE DON'T HAVE TIME