International Court says countries must address climate crisis in landmark opinion

The top United Nations court, the International Court of Justice (ICJ), ruled on Wednesday that nations would be breaking international law if they did not contribute to defending the globe from persistent climate problems.

A clean, healthy, and sustainable environment is a human right, and the court’s unanimous ruling, hailed by legal experts and climate advocates as a new era of accountability, may mark a potential turning point in international climate law.

According to Georgetown Law professor Shana Tabak, who specializes in the intersection of the climate crisis and human mobility, “the U.S. will find itself further isolated on the world stage of global climate policy if this decision is referred to and internalized into the state practice of the global legal community.” “If states heed this warning, as the Court aims for them to do, we can hope to see states more aggressively pursuing energy transitions not reliant on fossil fuels; countries like the US that choose to ignore this will be left behind in the global economy.”

The ICJ president, Judge Yuji Iwasawa, explained that the enjoyment of numerous human rights, including the right to life, the right to health, and the right to a sufficient quality of living, which includes access to food, water, and housing, depends on such an environment.

Although advisory opinions are not legally enforceable, they are usually regarded as authoritative as the World Court distills and summarizes existing law rather than making new laws.

They can, however, be used to support political or climate talks, pressure nations to enact more robust climate laws, and provide as a basis for figure litigation against corporate polluters.

Judge Iwasawa also out that the problem of climate change can only be partially resolved by international law.

According to him, the issues raised are not just legal; they are planetary existential issues that threaten the survival of all species on Earth as well as the health of the planet itself. All areas of human knowledge, including economics, science, law, and others, must contribute to a comprehensive solution to this difficult and self-inflicted issue.

In 2023, a panel of 15 judges in the Netherlands’ Great Hall of Justice will consider two primary questions to safeguard the rights of current and future generations against the negative effects of climate change after the UN asked the ICJ to review and provide advisory opinions on states’ obligations regarding these impacts:

• What are countries obliged to do under international law to protect the climate and environment from human-caused greenhouse gas emissions?
• What are the legal consequences for governments when their acts, or lack of action, have significantly harmed the climate and environment?

According to the court, state parties are in fact required to take action to reduce greenhouse gas emissions, and they also have a responsibility to work together to achieve this objective.

Legal repercussions: If a state violates a duty, the court recommends that the nation be held responsible by stopping improper behavior, promising not to do it again, and providing full compensation.

The United States, which withdrew from the Paris Climate Agreement for the second time after President Donald Trump took office in January 2025, is one of the states that must still fulfill comparable obligations under customary international law, according to the International Court.

Furthermore, the Court observes that a State’s refusal to control the production, consumption, licensing, or subsidies of fossil fuels may “constitute an internationally wrongful act” without specifically mentioning the United States.

A grassroots campaign in the tiny Pacific island nation of Vanuatu started the historic case, which eventually garnered support from more than 100 other nations and resulted in an unparalleled number of written comments to the court.

The fight for climate justice has won! After the delivering of the opinion, Seb Duyck, a senior lawyer at the Center for International Environmental Law, posted on X. A new age of accountability will be made possible by the Court’s endorsement of legal principles regarding fossil fuels, the right to a healthy environment, historic responsibility, compensation, and the obligations of States withdrawing from Paris.

In addition to two weeks of hearings at the ICJ last December, the court has spent the last two years examining several international conventions in order to make its ruling.