Landmark Legal Decisions Could Shape Global Climate Action

In a pivotal moment for global climate governance, the world’s top court is set to deliver an advisory opinion that could redefine the legal obligations of governments in the fight against climate change. This decision, anticipated to be issued by the International Court of Justice (ICJ), is part of a broader trend of landmark legal cases that experts believe may significantly influence climate action worldwide.

The Rise of Climate Litigation

Over the past decade, frustration with the slow pace of political action on climate change has led individuals, organizations, and even entire nations to turn to the courts. Andrew Raine, deputy director of the United Nations Environment Programme’s law division, explained that as political systems fail to deliver, the law has increasingly become a tool for enforcing commitments and driving ambition in climate action.
This shift has been supported by increasingly precise climate science, including the findings of the Intergovernmental Panel on Climate Change (IPCC). According to the Grantham Research Institute, nearly 3,000 climate-related cases have been filed in 60 countries as of the end of 2024. While many of these cases have not been successful, several landmark rulings have pushed governments to take stronger action.

Notable Climate Legal Cases

One of the most notable cases was the 2019 ruling by the Dutch Supreme Court, which ordered the government to reduce greenhouse gas emissions by 25% by the end of 2020. Similarly, in 2021, the German Constitutional Court ruled that the government’s failure to cut emissions sufficiently placed an unacceptable burden on future generations.

Historic Legal Milestones

Two recent advisory opinions have been hailed as watershed moments in climate litigation. The International Tribunal for the Law of the Sea declared in 2024 that carbon emissions constitute a marine pollutant, and that countries have a legal duty to reduce their impact on the oceans. This ruling expanded the scope of climate obligations beyond the Paris Agreement and the UN climate negotiations, challenging the argument that the UN framework alone is sufficient.

Another significant development came from the Inter-American Court of Human Rights, which affirmed the right to a healthy climate system and acknowledged the rights of nature. Perhaps most profoundly, the court equated the protection against irreversible climate harm with international prohibitions on genocide and torture, a statement that has been described as the strongest yet by any international court on the duty of states to avoid severe ecological destruction.

What Comes Next?

Vanuatu, a low-lying island nation threatened by rising sea levels, has asked the ICJ to provide an opinion on the legal obligations of states to reduce emissions. However, the more controversial question is whether there could be legal consequences for major polluters who cause severe climate damages. This raises complex issues of global justice, including the potential for reparations for those least responsible for emissions.

While the advisory opinions of the ICJ are not legally binding, they carry significant weight in shaping international law and influencing national courts, legislation, and public discourse. As Raine noted, these opinions clarify where the law stands and where governments should be heading in their climate efforts.

As the world awaits the ICJ’s decision, the legal landscape is rapidly evolving, and the role of courts in shaping climate policy is becoming more prominent than ever before.