In December, 15 judges at the International Court of Justice (ICJ) heard more than 100 oral arguments in perhaps the most significant international legal case on the climate crisis to date. 

The landmark case follows years of lobbying by Small Island States, spearheaded by Vanuatu. This prompted the UN General Assembly in 2023 to call on the ICJ to issue an advisory opinion to clarify two legal issues: the obligations of states under international law to combat the climate emergency, and the legal consequences of failing to meet or breaching these obligations

These are the largest proceedings ever handled by the ICJ, with 91 written statements filed by states and a further 62 comments submitted by states, international organisations and civil society groups. A record 97 states and 11 organisations participated in the oral proceedings held in The Hague from 2–13 December. 

Many developing nations questioned whether the obligations of states should extend beyond the existing UN Framework Convention on Climate Change (UNFCCC) and the Paris Agreement. ‘As pointed out by some states in the proceedings, historical polluters continue to hide behind the safety of the climate regime, which limits state responsibility to procedural obligations that avoid any real accountability’, said Arnold Kiel Loughman, Attorney General for the Republic of Vanuatu, in his address to the Court.

However, David Waskow, Director of the International Climate Initiative at the World Resources Institute in Washington, DC, believes the worsening nature of the climate crisis could necessitate an overhaul of the current framework. ‘I don’t know that the Paris Agreement covers the terrain adequately and so having the ICJ case really shines a light on where we stand and what the dimensions of the crisis are’, he says.

Taylor urged the Court ‘to ensure that its opinion preserves and promotes the centrality of this regime’. She also ventured whether the ICJ was the most appropriate forum to address climate justice and reparations. 

The ICJ isn’t the only international court grappling with high stakes advisory opinions relating to the climate crisis. In May the International Tribunal for the Law of the Sea issued an advisory opinion clarifying that greenhouse gas emissions absorbed by oceans constitute marine pollution and said states must take ‘all necessary measures’ to reduce emissions and protect the sea.

In early 2023, Chile and Colombia presented a joint request for an advisory opinion to the Inter-American Court of Human Rights (IACtHR) to clarify the effects of climate change on human rights.

The two countries have also stressed the need for regional standards to accelerate action across Latin America. This is particularly pertinent ahead of COP30, which will take place in Belém, Brazil, in November. 

Commentators believe the IACtHR will now be eagerly awaiting the ICJ’s advisory opinion, which is expected to be issued later in 2025. The need for the Court’s advisory opinion is particularly pressing in the wake of continued examples of wildfires and mass flooding around the world. Earlier in January, scientists and meteorologists confirmed that 2024 was the first full calendar year to register a global mean temperature of more than 1.5 Celsius above the pre-industrial average.

Although the ICJ proceedings were driven by countries in the Global South, they have also drawn attention to the devastating impact of the climate emergency on Indigenous communities more globally. ‘Around the world, climate change disproportionately endangers both the territorial and cultural integrity of Indigenous communities’, says Kevin O’Callaghan, Member of the IBA Business Human Rights Committee Advisory Board. ‘Canadians are particularly alive to this issue because of how climate change threatens our Arctic communities and their traditional ways of life.’ 

O’Callaghan, who’s Leader of the Indigenous Legal Matters group at Fasken Martineau DuMoulin in Vancouver, believes having so many collective Indigenous voices highlighting the plight of their communities and rights under legal obligations such as the UN Declaration on the Rights of Indigenous Peoples will only serve to help shape future international law and governance on these issues. ‘By referencing international agreements that acknowledge the unique position of Indigenous communities facing climate change, these nations are providing the ICJ with important language that may help inform their advisory opinion, and ultimately the formulation of international law’, he says. 

Although ICJ advisory opinions aren’t binding, they can carry considerable moral weight. ‘The movement that was started by the students of the Pacific and taken on by governments has reached a point where it’s getting so much attention by the highest court’, says Harjeet Singh, Global Engagement Director at the Fossil Fuel Non-Proliferation Treaty Initiative, based in New Delhi. ‘That is important not only to set the tone and fix the responsibility of countries and corporations who are responsible for the crisis, but to also provide a moral imperative that should be used by society.’

Singh hopes the advisory opinion will also mobilise citizens to put pressure on both ‘perpetrators of the climate crisis’ and policymakers who are in a position to act. ‘The advisory opinion from the ICJ is […] definitely going to set the framework for hard laws in many countries’, he says.

Thank you to Emily Morison, a member of the IBA’s Legal Policy & Research Unit, for her assistance with this article.
 

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