ICJ Opinion Opens Door To Climate Lawsuits Between Countries

The International Court of Justice (ICJ), the UN’s highest court, has issued an advisory opinion stating that countries can take legal action against one another for the effects of climate change, including damages caused by historic greenhouse gas emissions.

The opinion, delivered on Wednesday in The Hague, follows a request made by a coalition of climate-vulnerable states, led by the Pacific Island nation of Vanuatu. The move was originally proposed in 2019 by a group of Pacific Island law students concerned about the increasing effects of global warming on their countries.

While the ruling is non-binding, legal experts say it could significantly shape international climate law. It confirms that governments have legal duties to prevent environmental harm under international law, even outside specific agreements like the Paris Climate Agreement.

Flora Vano, a representative from Vanuatu, responded to the ruling by saying it reflects the experiences of countries dealing with climate-related damage. “This is a victory not just for us but for every frontline community fighting to be heard,” she said in a public statement shared by Pacific Islands Students Fighting Climate Change.

Over 50 countries supported the request to the court, many from the Global South. These countries argue that wealthier, industrialised nations have contributed the most to global emissions while failing to deliver on climate finance and emissions-reduction commitments.

Court Says Existing Agreements Are Not Sufficient

The ICJ dismissed claims by some developed nations, including the United Kingdom, that existing international climate agreements such as the 2015 Paris Agreement already set out adequate obligations. The judges stated that broader international legal principles also apply, meaning all countries, whether or not they are party to the Paris Agreement, are still responsible for preventing significant environmental damage.

Judge Iwasawa Yuji explained that failure to pursue “the most ambitious possible policies” to reduce emissions could be seen as a breach of legal commitments. He also stated that not taking sufficient action may amount to an “internationally wrongful act,” as quoted by the Associated Press.

The court stated that countries suffering irreversible harm from climate change, such as the loss of land due to rising sea levels or destruction caused by severe storms, may seek compensation when restoration is not possible. However, any claims would require evidence that the damage was caused or worsened by the actions of specific countries. These would need to be assessed individually, and proving direct causation is likely to be complex.

Potential for Future Compensation Claims

The opinion does not create a new enforcement mechanism, but it offers legal backing that could be used in other courts or negotiations. Previous ICJ advisory opinions have influenced state decisions, such as the UK’s agreement to begin returning the Chagos Islands to Mauritius, as reported by the BBC.

Climate lawyers and campaigners say the ruling could influence future attempts to claim compensation, especially as the costs of climate-related damage continue to rise. A 2022 study published in Nature estimated global climate damages between 2000 and 2019 at $2.8 trillion — roughly $16 million per hour.

Developing nations have increasingly raised concerns that major polluters are not meeting existing promises to reduce emissions or provide financial support for adaptation and recovery. The ICJ’s opinion adds to growing pressure on high-emitting countries to take stronger action and accept responsibility for the consequences of climate change.

While the ruling does not automatically trigger payments or sanctions, it signals a shift in how international law may be used to address the climate crisis. Governments will now need to consider how their climate policies align not only with political agreements but with broader legal obligations under international law.