Top U.N. Court Says Countries Must Act on Climate Change

New York Times

23-07-2025

The International Court of Justice issued a strongly worded opinion on Wednesday saying that states must protect people from the 'urgent and existential threat' of climate change, a major moment for the global environmental movement and for the countries at greatest risk of harm.
It was the first time that the court, which is the United Nations' highest judicial body, has weighed in on climate change.
The unanimous opinion said that the failure of nations to take action to protect the climate system may constitute 'an internationally wrongful act.' It also found that protection of the environment is 'a precondition' for ensuring human rights and cited government support of fossil-fuel production as a potential violation of these principles.
'The environment is the foundation for human life, upon which the health and well-being of both present and future generations depend,' Judge Iwasawa Yuji, president of the court, said.
Although the International Court of Justice has no mechanism to enforce an advisory opinion like this on nations, as a statement of legal principles the findings nevertheless could have far-reaching influence on litigation in courts around the world as well as on international negotiations over climate policy and funding.
The United Nations General Assembly requested the opinion after a spirited, yearslong campaign organized by law students from Vanuatu and other Pacific islands. That led to a two-week hearing in December at which more than 100 countries, organizations and experts addressed the court, hoping to influence the opinion.
The court's 15 judges were asked to address two main questions, including what countries are obliged to do, under existing international laws and treaties, to protect the climate system and environment from greenhouse gasses; and what the legal consequences are if, by their acts or omissions, they have caused significant harm. The panel, also known as the World Court, is based in The Hague.
Powerful fossil fuel producers, including the United States and Saudi Arabia, argued before the court that the 2015 Paris accord, in which nearly all countries agreed to limit greenhouse gasses, was sufficient to address climate change. (The U.S. arguments were presented near the end of the Biden administration, and since then, President Trump has withdrawn the United States from the Paris Agreement.)
Other countries argued that the court should take action, saying that because the Paris Agreement has no enforcement mechanism, it would be insufficient to halt the rapid pace of global warming, which is causing higher temperatures, rising oceans and increasingly dangerous storms.
Many argued during the hearings that the countries that have emitted the most planet-warming carbon dioxide should pay reparations to other countries suffering from the effects of global warming. Some low-lying Pacific and Caribbean islands, which are especially vulnerable to storms, flooding and sea level rise, have been particularly outspoken.
When Ralph Regenvanu, the climate envoy from Vanuatu, addressed the court in December, he said his country was on 'the frontline of a crisis we did not create.' He asked the court 'for recognition that the conduct which has already caused immense harm to my people and so many others, is unlawful, that it must cease and that its consequences must be repaired.'
The judges also held a private briefing session with a group of scientists from the International Governmental Panel on Climate Change, a U.N. body. There is overwhelming scientific consensus that greenhouse gas emissions from the burning of coal, oil and other fossil fuels is driving global warming.
The opinion could open the door to more lawsuits over climate damage around the world, and it comes on the heels of other recent notable opinions from international legal bodies. This month, the Inter-American Court of Human Rights, based in Costa Rica, found that countries have an obligation to prevent harms from climate change as a matter of human rights. Its decision applies to many countries in the Americas.
Last year, International Tribunal for the Law of the Sea, the world's highest court dealing with the oceans, concluded that governments must take measures to address greenhouse gas emissions. That specialists' decision had been expected to influence the judges in The Hague.
In another closely watched case last year, Europe's top human rights court found that the Swiss government had violated its citizens' human rights by not doing enough to stop climate change, after a lawsuit brought by a group called KlimaSeniorinnen, or Senior Women for Climate Protection.
The African Court on Human and Peoples' Rights, which was established by the African Union and is based in Tanzania, has also been asked to provide an opinion on human rights and climate change.
The decision in The Hague could influence proceedings in local courts around the world, which are seeing growing numbers of lawsuits related to climate change. On Monday, for example, Italy's highest court ruled that judges can hear climate change lawsuits to protect human rights, after a case filed by two nonprofit groups, Greenpeace Italy and ReCommon, against the energy company Eni.
The lawsuit alleges that the company's strategy to reduce greenhouse gas emissions is not in line with the Paris Agreement and that the company's contribution to climate change violates human rights. In a statement, the company said it looked forward to adjudicating the suit, which it said was driven by 'unfounded and often misleading slogans of the two associations.'
Around the world, climate-change litigation is increasingly reaching high-level legal venues, such as appellate or supreme courts, according to a recent study by the Grantham Research Institute on Climate Change and the Environment in London. The study noted many cases filed in the United States, where state attorneys general, youth activists and environmental nonprofits have filed lawsuits seeking damages from oil companies or changes in government policy.
But it also found a growing number of lawsuits in the United States by opponents of climate action, such as challenges to energy-efficiency standards and efforts to restrict investing that gives weight to environmental or social principles, which has become a major target of Republican leaders.
Harj Narulla, a British lawyer who represented the Solomon Islands in the International Court of Justice case, said that the way national courts might use the precedent would depend on the country and case. 'The decision will be a significant help to climate lawyers around the world, and it will strengthen their cases against corporations and government policies,' he said.
He said international law was automatically incorporated into domestic law in some countries, such as France and Germany, making the decision much more likely to have a direct influence on litigation there. In other countries, the opinion could be cited in cases challenging governmental climate policies.
He noted, though, that the United States is an outlier among democracies in giving less credence to the decisions of international courts.
He predicted that litigation citing the court's opinion would seek to stop new oil and gas projects or seek to compel countries to set tougher goals for reducing the emissions of greenhouse gases. Other prospective legal applications of the court's opinion, he said, might be to support communities adapting to the effects of climate change.
Robert Percival, director of the environmental law program at the University of Maryland's law school, said that while the court's findings were largely symbolic, they would still carry weight. 'It is the one body that's the most authoritative in declaring what international law is or should be,' he said. 'I think people will pay a lot of attention.'