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, after the International Court of Justice (ICJ) ruled that harming the climate is a breach of international law.

In a landmark case brought by the sinking Pacific island nation of Vanuatu, the ICJ’s 15 judges decided unanimously that governments have a legal duty to protect the climate. Breaching that duty, they said in a keenly awaited advisory opinion, could result in the affected countries claiming compensation.

Climate litigation expert Joana Setzer, of the London School of Economics’ Grantham Research Institute on Climate Change and the Environment, said that “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.”

The ICJ says its advisory opinions are not binding. But 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.

Ralph Regenvanu, Vanuatu’s minister of climate change, told a press conference in The Hague that the ruling is a “historic landmark” for climate action, going “above and beyond” his expectations.

“[The 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, and these obligations are granted in international law,” he said. 

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Reading out the ruling at the court’s headquarters in The Hague, ICJ president Yuji Iwasawa said “this is a concern of planetary proportions that imperils all forms of life”. The judge added that “the court presents this opinion with a hope 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, the director of Pacific Islands Students Fighting Climate Change, said “governments can no longer turn a blind eye to their legal responsibilities”. 

High-emitting countries like the United States and China 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.

“Internationally wrongful” acts

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 opinion mentions fossil fuel production and consumption, granting fossil fuel exploration licenses and providing fossil fuel subsidies. 

Harjeet Singh, founding director of India’s Satat Sampada Climate Foundation, said 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.

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The court also found that the more than 190 governments which signed up to the Paris Agreement have a duty to submit climate plans consistent with limiting global warming to 1.5C, which it confirmed as the primary goal of the UN pact. Governments are drawing up and publishing their latest round of nationally determined contributions this year.

Door open to legal claims

If governments fail to fulfill their climate responsibilities, including on fossil fuels, the ICJ said other courts could order them 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 Center 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”.

From Vanuatu to the world

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 Fi