In a ground-breaking climate ruling, the International Court of Justice (ICJ), the prime judicial organ of the United Nations, on Wednesday delivered a landmark unanimous advisory opinion, addressing the legal obligations for countries to address climate change under international law.
Presenting the opinion in The Hague, court’s President Iwasawa Yuji said greenhouse gas emissions are “unequivocally” caused by human activities and acknowledged the “urgent and existential threat” posed by climate change.
“The consequences of climate change are severe and far-reaching. They affect both natural ecosystems and human populations. These consequences underscore the urgent and existential threat posed by climate change,” said Iwasawa.
The case was brought forward by Vanuatu and other Pacific Island nations, after a youth-led movement in 2019 campaigned for it to be brought in front of the ICJ.
Before the court’s 15 judges were two fundamental questions that is the obligations of states (nations) in respect of climate change — What are states’ obligations under international law to address climate change for present and future generations? And what are the legal consequences under these obligations for states failing to do so?
The ICJ, the principal judicial organ of the UN, delivers its opinion that comes as global pressure mounts on fossil fuel producers, with courts worldwide increasingly citing the unequivocal scientific evidence that a rapid phaseout of fossil fuels is essential to meet climate goals and protect human rights.
In response to the ruling by the ICJ, Mohamed Adow, Director of Nairobi-based think-tank Power Shift Africa, told Media: “This ruling is a rocket boost for climate justice. The ICJ has confirmed what Africa has long demanded that rich nations must be held accountable for the damage their emissions have caused.
“For a continent like Africa — least responsible but most affected — this decision is a lifeline. It strengthens our call for reparations, debt relief, and real climate finance — not loans that deepen poverty.
“The era of polluters hiding behind vague promises is over. Africa will not be a sacrificial lamb for the excesses of others. The law now backs our moral case. It’s time for rich nations to pay their climate debt and support a just transition powered by Africa’s renewable energy potential.”
Describing the ICJ’s historic advisory opinion a watershed moment in the fight for climate justice, New Delhi-based climate activist and founding director of Satat Sampada Climate Foundation, Harjeet Singh, told Media: “It’s a resounding declaration that the era of impunity for polluters and complicit states is over. This landmark decision unequivocally 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.”
He said the court’s findings pave the way for full reparations, meaning polluters must not only cease their harmful actions but also provide financial compensation for losses and damages incurred. This includes compensation for climate harm and, critically, an immediate cessation of greenhouse gas emissions above science-based safety thresholds.
The ICJ was established by the United Nations Charter in June 1945 and began its activities in April 1946. The court is composed of 15 judges elected for a nine-year term by the General Assembly and the Security Council of the United Nations. The seat of the court is at the Peace Palace in The Hague in the Netherlands.
ICJ President Yuji said: “This is a concern of planetary proportions that imperils all forms of life…The court presents this opinion with a hope that it hopes its conclusions will allow the law to inform and guide social and political action to solve the ongoing climate crisis.”
She said: “Failure of the state to take appropriate action to protect the climate system from GHG emissions, including through fossil fuel production, fossil fuel consumption, the granting of fossil fuel exploration licenses or the provision of fossil fuel subsidies may constitute an internationally wrongful act which is attributable to that state.”
Climate experts say as a powerful new legal tool, the ICJ’s decision will spark a chain reaction that accelerates climate litigation on a global scale.
Courts worldwide are likely to reference this ruling in their upcoming decisions. It will also strengthen legal arguments in ongoing and future climate lawsuits, especially those targeting corporate defendants like fossil fuel companies.
The ruling clarifies that international law requires more than voluntary action, including obligations for historical polluters to reduce emissions and provide compensation to climate-affected communities.
It also reaffirms the primacy of climate science, offering an opportunity to reinvigorate global climate talks with legal clarity on rights and responsibilities.
The groundbreaking campaign for an advisory opinion was conceived in 2019 by law students from the University of the South Pacific. Working with the government of Vanuatu, Pacific Island Students Fighting Climate Change (PISFCC) and World’s Youth for Climate Justice (WYCJ) helped secure a unanimous vote at the United Nations to request the opinion, with support from more than 1,500 organisations.
