The Obligations of States in respect of Climate Change | What does the International Court of Justice Advisory Opinion mean for Loss and Damage under the UN climate change regime?

The International Court of Justice’s 2025 Advisory Opinion on the obligations of states in regard to climate change marks a turning point: it clarifies that climate change is firmly recognised as a matter of international law. States and private actors have binding obligations to prevent climate harm, to co-operate in addressing Loss and Damage being suffered by nature and people, and to uphold human rights in their responses.

This negotiator's brief distills the Advisory Opinion’s key findings for work under the UN climate change regime which includes the United Nations Framework Convention on Climate Change and Paris Agreement — especially for the Fund for Responding to Loss and Damage, and the Warsaw International Mechanism for Loss and Damage’s Executive Committee, Expert Groups and Santiago Network.

The thirtieth meeting of the Conference of the Parties to the UNFCCC (COP 30) in Belem, Brazil in November 2025 presents the next opportunity for the Advisory Opinion to be used to support efforts to secure urgently needed progress in multilateral negotiations on climate change. Negotiators and other relevant stakeholders can reflect on the recommendations in this brief that provide guidance on how to:

1. Use the Advisory Opinion as a legal and diplomatic tool;
2. Frame negotiation arguments around international law;
3. Align COP/CMA decision text with ICJ findings; and;
4. Strengthen political messaging and ambition.

As climate change escalates and irreversible harm becomes more common, it is crucial that responding to loss and damage becomes the ‘third pillar’ of climate action, alongside mitigation and adaptation.

Read this brief to understand how the ICJ’s findings can inform negotiations at COP 30 in Belém and beyond — and help to secure justice for those on the frontlines of the climate crisis.