On July 23, 2025, the International Court of Justice (ICJ) in The Hague delivered a landmark advisory opinion that could reshape international climate action and accountability. The court unanimously declared that countries have a legal obligation to take meaningful measures to protect the planet from climate change, warning that failure to do so may constitute a violation of international law. This ruling opens the door for nations harmed by climate change to seek reparations and empowers citizens and activists worldwide to hold governments accountable for failing to safeguard their human rights in the face of an existential crisis.
ICJ President Yuji Iwasawa emphasized the gravity of the situation, stating, "Failure of a state to take appropriate action to protect the climate system ... may constitute an internationally wrongful act." He described the climate crisis as "an existential problem of planetary proportions that imperils all forms of life and the very health of our planet." The court also recognized that a "clean, healthy and sustainable environment" is a fundamental human right, a declaration that is expected to influence future legal actions and policy decisions globally.
The case was initiated by the Pacific island nation of Vanuatu, supported by over 130 countries, many of which are vulnerable to climate disasters. The United Nations General Assembly had requested the ICJ's advisory opinion in 2023, explicitly asking what obligations countries have under international law to combat human-caused greenhouse gas emissions and what legal consequences arise from inaction.
During hearings in December 2024, Arnold Kiel Loughman, attorney general of Vanuatu, poignantly stated, "The survival of my people and so many others is on the line." This sentiment reflects the urgency felt by many small island states facing rising sea levels. In the decade leading up to 2023, global sea levels rose by an average of 4.3 centimeters (1.7 inches), with some Pacific regions experiencing even greater increases. The planet has warmed by approximately 1.3 degrees Celsius (2.3 Fahrenheit) since preindustrial times, largely due to fossil fuel combustion.
Vanuatu's Minister for Climate Change, Ralph Regenvanu, hailed the ruling as a "very important course correction in this critically important time," adding that the decision "exceeded expectations". He noted that the advisory opinion gives Pacific island nations "much greater leverage" in international climate negotiations and dealings with major emitters like Australia.
The ICJ's ruling extends beyond mere climate treaties. While some countries, including Australia, the United States, and China, had argued that their obligations were confined to compliance with the 2015 Paris Agreement and the United Nations Framework Convention on Climate Change, the court found otherwise. It ruled that countries have binding obligations under international human rights law, the law of the sea, and customary international law to act against climate change. This includes regulating fossil fuel production, consumption, subsidies, and exploration licenses.
Legal experts see the ruling as a powerful new tool for climate justice. Michael Gerrard, professor and director of the Sabin Center for Climate Change Law at Columbia Law School, explained that while the ICJ's opinion is advisory and non-binding, it "empowers domestic courts and the advocates before domestic courts to do much more." He highlighted that the ruling encourages major polluters to meet and maintain the standards set in the Paris Agreement, despite some countries having withdrawn from it. For instance, the United States, under the Trump administration, had withdrawn from the Paris Agreement and is currently drafting measures to limit federal regulation of greenhouse gas emissions, making climate data less accessible.
The ICJ specifically reaffirmed the 1.5°C global warming limit as the scientifically based consensus target under the Paris Agreement. It stipulated that each country’s emissions reduction pledges must contribute adequately to this global goal and be judged against a stringent "due diligence" standard, accounting for historical emissions, development levels, and national circumstances. This means wealthier nations, such as Australia, are legally required to adopt more ambitious targets. Dean Bialek, an international lawyer and former lead climate negotiator for island nations, noted that Australia should set a 2035 emissions reduction target of at least 75% below 2005 levels to comply with the ruling.
Climate activists have welcomed the ruling as a turning point. Vishal Prasad, a law student who helped lobby for the case, called the ICJ's opinion "a strong tool to carry on the fight for climate justice." The decision also provides a legal foundation for vulnerable nations to seek compensation or other remedies if they suffer damage due to other countries’ failure to fulfill their climate obligations. The court clarified that nations can be held liable even if climate damage results from multiple causes, including private actors like companies, underscoring the responsibility of states to regulate such entities.
In Australia, the ruling has already sparked debate. Ralph Regenvanu warned that Australia, as the world's third-largest fossil fuel exporter and a significant emissions contributor, is committing "internationally wrongful acts" by subsidizing fossil fuel production and excessive emissions. Environmental groups and politicians echoed these concerns. Larissa Waters, leader of the Australian Greens, stated, "Every one of Labor’s new coal or gas approvals risks Australia being legally liable for the climate consequences." Wesley Morgan, a climate risk researcher, urged the government to "heed the message from The Hague," noting that "the days of impunity for the fossil fuel industry are coming to an end." Meanwhile, a federal government spokesperson expressed pride in co-sponsoring the Vanuatu-led initiative and reaffirmed a commitment to strengthening global climate action, despite internal debates over net-zero targets.
Globally, the ruling adds to a growing body of legal decisions affirming states’ duties to protect the environment. Earlier in July 2025, the Inter-American Court of Human Rights ruled that countries have a legal duty not only to avoid environmental harm but also to protect and restore ecosystems. In 2024, the European Court of Human Rights mandated that countries better protect their populations from climate change consequences. The Netherlands’ Supreme Court had already recognized protection from climate change effects as a human right in 2019.
Looking ahead, the ICJ’s advisory opinion is expected to influence the upcoming United Nations climate conference (COP30) scheduled for November 2025 in Belém, Brazil, itself a significant emitter. Climate activists and legal experts hope the ruling will spur more ambitious commitments and enforcement mechanisms. Erika Lennon, senior attorney at the Center for International Environmental Law, urged states to use the ICJ decision to "advance ambitious outcomes at COP30 and beyond. People and the planet deserve it."
While the advisory opinion is not legally binding, its unanimous backing by the ICJ’s 15 judges and its grounding in human rights law and scientific consensus give it substantial moral and political weight. As former U.N. human rights chief Mary Robinson remarked, "The world’s highest court provided us with a powerful new tool to protect people from the devastating impacts of the climate crisis — and to deliver justice for the harm their emissions have already caused."
In the face of mounting climate threats, the ICJ ruling signals a new era of accountability and hope, where the law joins science and activism in the urgent quest to secure a sustainable future for all.
