Historic ICJ climate ruling shows small States’ power
By Alberto Leny, July 28, 2025Developing nations and campaigners have hailed the International Court of Justice (ICJ) ruling that governments have a legal duty to prevent and repair damage to the climate system.
In a landmark case brought by the sinking Pacific island nation of Vanuatu, the ICJ’s 15 judges on Wednesday, July 23, 2025, decided unanimously that governments have a legal duty to protect the climate.
Breaching that duty, they said in a long-awaited advisory opinion, could result in the affected countries claiming compensation.
The ruling means that governments of countries that have driven global warming with their planet-heating emissions could be held legally accountable for the damage caused to other nations.
For the developing nations, the world’s top court’s ruling opens the door to compensation from countries responsible for the climate crisis.
The ICJ judgement recognises the power of small states. While Vanuatu’s initiative acknowledged the failures of the climate change negotiations, it exemplifies the unique ways that small island developing states can exercise power.
It carries huge political significance because the ICJ has made a judgement that powerful polluting countries would not have wanted to hear.
Climate litigation expert Joana Setzer, of the London School of Economics’ Grantham Research Institute on Climate Change and the Environment, told Climate Home News, the award-winning independent digital publication covering the international politics of the climate crisis:
“For the first time, the world’s highest court has made clear that states have a legal duty not only to prevent climate harm – but to fully repair it.”
Creating accountability
Although the court’s advisory opinions are not binding, legal experts stress that while they do not create new law, they clarify it, and the opinion will be referred to as authoritative guidance in future domestic and international climate lawsuits, as well as during UN climate negotiations.
Speaking shortly after the ruling, Vanuatu’s minister of climate change, Ralph Regenvanu, said it was a “historic landmark” for climate action, going “above and beyond” his expectations.
“The advisory opinion confirms what vulnerable nations have been saying and we’ve known for so long: that states do have legal obligations to act on climate change”
ICJ President Yuji Iwasawa said through the court’s opinion, it is hoped that its conclusions “will allow the law to inform and guide social and political action to solve the ongoing climate crisis.”
Celebrating the ruling, Vishal Prasad, Pacific Islands Students Fighting Climate Change director, said governments can no longer turn a blind eye to their legal responsibilities.
High-emitting countries, including the United States and China, and the fossil fuel-producing and exporting countries argued in a two-week hearing last December that international climate accords like the 2015 Paris Agreement should determine governments’ obligations on climate change rather than the world’s courts.
But the ICJ’s judges ruled that states’ responsibilities to protect the climate are not limited to their obligations under UN climate agreements, adding that failure to meet that duty may constitute an internationally wrongful act “which is attributable to that State”.
As examples of failing to protect the climate, the advisory opinion mentions fossil fuel production and consumption, granting fossil fuel exploration licences and providing fossil fuel subsidies.
Harjeet Singh, founding director of India’s Satat Sampada Climate Foundation, told Climate Home the decision imposes robust obligations on States to compel fossil fuel producers to drastic and immediate action, holding them categorically responsible for the damage they’ve unleashed.
“This mandates a fundamental shift, where States must rigorously regulate, constrain and ultimately dismantle the fossil fuel industry’s capacity to inflict further harm,” added the veteran climate justice activist.
The court also found that the more than 190 governments that signed up to the Paris Agreement have a duty to submit climate plans consistent with limiting global warming to 1.5°C, which it confirmed as the primary goal of the UN pact.
Governments are drawing up and publishing their latest round of Nationally Determined Contributions (NDCs) for the UN’s new deadline in September after most countries missed the earlier largely symbolic 10 February deadline.
Climate compensation
UN Secretary-General António Guterres has invited world leaders to present their NDCs at a high-level summit due to take place on September 24, 2025, in New York on the sidelines of the UN General Assembly.
If governments fail to fulfil their climate responsibilities, including on fossil fuels, the ICJ said they could be ordered to change their policies or make up for the damage they have caused to other countries by, for example, rebuilding infrastructure or restoring ecosystems damaged by climate change.
The court acknowledged that restitution is not always possible, paving the way for compensation to be paid instead. The judges did not rule on which countries should pay compensation, who they should pay or how much, leaving that to be determined according to circumstances in future legal cases.
Sebastien Duyck, a lawyer from the Centre For International Environmental Law, said the case “opens the door for further legal claims” and “reshapes what is now considered legally possible, actionable, and ultimately enforceable”.
The judgment handed down on Wednesday is the culmination of years of campaigning by a group of young law students from Pacific nations and international diplomacy led by Vanuatu.
The students first petitioned their teachers back in 2019 about their idea – crowdfunding 80 Fijian dollars (US$35) for a banner – and then lobbied their government, winning the support of Regenvanu.
Together, their efforts resulted in a UN General Assembly resolution in March 2023 calling on the ICJ to provide an advisory opinion on the legal obligations of states to address climate change and the consequences if they fail to do so.
Prasad, one of the Pacific students who led the initiative, said the ICJ ruling tells the world that “climate impunity is no longer allowed and that those who have caused the greatest harm are required to provide a remedy to people most affected.”
“For small island states, communities in the Pacific, and for young people, this opinion is a lifeline and an opportunity to protect all we hold dear and all that we love,” Prasad said.
In reaching its advisory opinion, the International Court of Justice considered various sources of law, including international climate treaties, human rights principles, the law of the sea and customary international law – which is often unwritten and arises from what governments do in practice.
In a similar case seen as setting a precedent, the International Tribunal for the Law of the Sea (ITLOS) ruled in May 2024 that governments must go beyond their commitments under the Paris Agreement to protect the oceans, which are ITLOS’s remit, from climate change.
Then, in a separate advisory opinion issued in early July, the Inter-American Court of Human Rights ruled for the first time that people have the right to a “healthy climate” without “dangerous” human interference, and urged states to regulate fossil fuel extraction and exploration.
“I am convinced now that there is hope,” said 28-year-old Prasad, commenting on Wednesday’s ICJ opinion.
“And that we can return to our families and communities back home in the Pacific, saying the same.”