CIVICUS discusses the International Court of Justice’s (ICJ) recent advisory opinion on climate change with Abdul Mufeez Shaheed, campaigner with Pacific Islands Students Fighting Climate Change.

On 23 July, the ICJ issued a landmark advisory opinion affirming that states have binding legal obligations to tackle climate change. This was a civil society victory: the case originated from an initiative by Pacific Island law students and evolved into a successful campaign that challenged governments to take meaningful climate action, establishing crucial legal precedents for climate justice efforts.

How did the ICJ’s advisory opinion on climate change come about?

The journey began with 27 young Pacific Island law students at the University of the South Pacific’s Vanuatu Campus doing an assignment for a class, which eventually became a campaign to bring a case before the ICJ.

Since the campaign needed state support, the students took their proposal to the Pacific Islands Forum leaders meeting, securing endorsement from all states in the region. Subsequently, Vanuatu brought the case to the United Nations (UN) General Assembly, which unanimously passed a resolution requesting the ICJ to clarify state obligations under international law regarding climate change and whether there should be special consideration for small island developing states and future generations.

Why is the advisory opinion significant?

The advisory opinion strengthens climate justice by establishing clear legal principles that states cannot ignore and civil society and communities can use as the basis for their advocacy campaigns and strategic litigation.

Drawing on various international conventions and treaties and customary international law, the opinion establishes that states have a duty to strengthen their nationally determined contributions (NDCs), the climate action plans each country submits under the Paris Agreement outlining how they will reduce emissions to contribute to the goal of keeping global warming under 1.5°C compared to preindustrial levels.

Reports from the Intergovernmental Panel on Climate Change, a UN body comprising thousands of scientists worldwide, now carry greater legal weight in guiding states on necessary actions, such as regulating corporations. The core obligation is based on a ‘do not harm’ principle regarding the environment and the people affected, while also requiring reparations for small island states.

The advisory opinion has strengthened the case for reparations and remedies for climate harm. The ICJ has essentially said that countries can be held liable for the breach of their obligations and to make reparations for any harm suffered.

What role did civil society play, and what challenges did you encounter?

The initiative started as a people’s movement that gradually received support from larger regional and international civil society organisations (CSOs) such as 350.org, Oxfam and the Pacific Climate Action Network. Key global and regional organisations and groups joined together in the Alliance for a Climate Justice Advisory Opinion, which eventually encompassed 96 organisations. The alliance leveraged its expertise and the lived experience of those most affected by climate change to pressure states and elected leaders.

Collaboration between CSOs saw the success of the campaign to secure global support for the General Assembly resolution, bridge the knowledge gap by raising awareness about the potential of the advisory opinion, build cross-pollinating movements across academia, civil society and states, collect testimonies and provide support for states’ oral and written submissions and, finally and most importantly, bring the voices of frontline communities to the ICJ through the People’s Petition, People’s Assembly and demonstrations at The Hague.

This case was particularly significant because international law was not created for global south communities but rather to safeguard western countries and their interests. However, this time the situation was different: global south communities, Indigenous groups, people with disabilities, queer people, women and young and older people participated directly in the international legal process, including by presenting oral and written submissions. The People’s Petition we gathered and stories from the region were presented directly to the ICJ judges.

What does this advisory opinion mean for the future of climate justice, and how do you plan to build on it?

While we had hoped the court would deliberate further, we feel positive about the text of the advisory opinion. Previously, there was little correlation between international law and environmental protection, but the court’s opinion creates significantly more space for climate advocacy. However, the advisory opinion is not our end goal but a tool to achieve climate justice.

The real work begins now, focusing on ensuring states comply with their obligations. Otherwise, this will remain a 144-page document with no practical impact. Under international law, states face immediate obligations to act and ongoing obligations to enhance their efforts over time, meaning they must submit updated and progressive NDCs before the COP30 climate summit in Brazil in November.

However, implementation requires collaboration and strategy. Many states struggle to balance climate action with pressure from corporations that prioritise profit over environmental and human welfare. Some states may align with international law in principle but fail to implement their obligations at the national level.

This is where civil society’s role is crucial. We must strengthen our advocacy work, developing capacity and understanding among grassroots and frontline communities. Young people have shown they can drive this process, drawing on cultural and traditional knowledge while caring about future generations, but meaningful progress requires widespread collaboration to improve climate ambition. We are continuing our work by helping civil society understand what still needs to be done and ensuring that implementation of the advisory opinion delivers real change.