Landmark court opinion shows the power of the youth climate movement

The Advisory Opinion last month by International Court of Justice on the obligations that states have with regard to climate justice was thanks to years of advocacy by the World’s Youth for Climate Justice. Now it must lead to action on fossil fuels

Activists demonstrate last month outside the International Court of Justice in The Hague, Netherlands, ahead of an advisory opinion on what legal obligations nations have to address climate change and what consequences they may face if they don't. File photo: AP/Peter Dejong

Last month, the world witnessed the power of youth. Years of advocacy led to an Advisory Opinion from the world’s highest court that states must take urgent action to prevent harm to the climate system, including by tackling fossil fuels, or face real legal consequences.

The campaign to bring climate justice before the International Court of Justice (ICJ) began with law students from the University of the South Pacific and grew to a worldwide movement, World’s Youth for Climate Justice. 

In campaigning for climate change to be brought to the world’s highest court, young people called attention to the obligations that states have not to destroy the future of people and the planet, and highlighted the day-to-day reality of frontline communities dealing with the existential threat posed by climate change. 

Working closely with Global South states, the movement successfully achieved a vote by the UN General Assembly in 2023 (which Ireland supported) to ask the ICJ for its views of what obligations states have under international law to address climate change, and, importantly, what consequences they may face for breaching these obligations.

In a decisive victory for the youth movement, the court confirmed what young people have known all along. States' obligations to address climate change are not just confined to their commitments under the 2015 Paris Agreement, but encompass a broad range of international law principles, treaties, and norms that must be taken into account to address the urgent threat posed by climate change. 

In particular, the court set out that states must take climate measures which reflect their "highest possible ambition" in accordance with the best available climate science and other considerations like intergenerational equity. This places the interests of young people—those who will inherit the consequences of today’s inaction—at the very core of climate governance.

The court’s opinion also affirmed the interdependence of environmental protection and human rights, stating that the right to a healthy environment is foundational to the enjoyment of all other rights. 

This reflects what young climate activists have long insisted: that climate inaction violates fundamental rights, deepens global inequalities, and exposes vulnerable communities to escalating hardship, displacement, and injustice.

Fossil fuels

Moreover, the court’s treatment of the international environmental law principle that states should refrain from acts of transboundary harm to the environment has profound implications for climate action. 

The court made clear that a state’s failure to fulfil its climate-related legal obligations may amount to an "internationally wrongful act," triggering international responsibility and potential consequences for that state. 

Crucially, it affirmed that inadequate action to curb greenhouse gas emissions, including continued fossil fuel production, consumption, licensing, and subsidies, may all contribute to such violations. 

This conclusion resonates strongly with the demands of youth activists, who have persistently highlighted that fossil fuel dependence is not just an environmental hazard, but a violation of international law, and that a fair transition is a legal and ethical imperative to prevent further harm to vulnerable communities.

As the court itself noted, law is only one part of the response needed to address the climate crisis. The Advisory Opinion is non-binding, but, importantly, we now have clear confirmation of state's obligations to address the (as the court stated) "existential problem of planetary proportions that imperils all forms of life and the very health of our planet". 

These obligations are not just words, they are an expression of the moral, political, and legal imperative to protect the only home we have. 

The International Court of Justice affirmed that inadequate action to curb greenhouse gas emissions, including continued fossil fuel production, consumption, licensing, and subsidies, may all contribute to violations. File photo

They add to the global call to deliver justice for communities harmed by activities which have polluted our air, endangered our health, and destroyed lives across the globe, particularly in the Global South and in vulnerable and marginalised communities.

Just as young people drove the effort to clarify states’ obligations, young people can now create further change in their communities and hold states accountable to these obligations. 

States and decision-makers at every level must implement calls for justice from marginalised communities, particularly those in the Global South who achieved this success. This moment must mark a turning point from legal clarification to real, enforceable action. 

The law is clear. Youth made it clear. Now, action must be too.

• Beth Doherty is Ireland’s Youth Climate Delegate for COP29. 
• Eoin Jackson is Irish Rapporteur for the Sabin Center for Climate Change Law and a PhD candidate in Climate Law at the London School of Economics.

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