International Court of Justice Advisory Opinion Proceedings underway on States’ obligations in respect of climate change

The International Court of Justice this week commenced hearings in the historic advisory opinion proceedings on the Obligations of States in respect of Climate Change.

Between 2 and 13 December, the International Court of Justice will hear oral submissions from a record number of 98 States and 12 intergovernmental organisations. These proceedings are the largest in the Court’s history by a considerable margin, indicative of the importance of the issues before the Court.

Catherine Drummond appeared on the opening day of the proceedings for Antigua and Barbuda, a small island developing State for which the climate crisis represents an existential threat. Antigua and Barbuda has emerged as a leading voice in efforts to combat climate change, including by establishing the Commission of Small Island States on Climate Change and International Law which last year spearheaded similar advisory opinion proceedings before the International Tribunal for the Law of the Sea.

The International Court of Justice proceedings arise from a request from the United Nations General Assembly on 29 March 2023, contained in Resolution 77/276, for the Court to opine on the following two questions:

• What are the obligations of States under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of greenhouse gases for States and for present and future generations?
• What are the legal consequences under these obligations for States where they, by their acts and omissions, have caused significant harm to the climate system and other parts of the environment?

The United Nations General Assembly request followed a campaign led by Vanuatu and championed by other small island States, including Antigua and Barbuda. Over the course of 2024, participating States and intergovernmental organizations submitted two rounds of detailed written submissions, addressing the specific legal questions referred to the Court. Following the hearing, the 15 Judges will prepare an Advisory Opinion that will become a crucial reference point for States in understanding what they must do in response to the climate crisis and the legal consequences of failing to take necessary action. The Advisory Opinion is expected in 2025.

In opening Antigua and Barbuda’s oral statement on Monday, Prime Minister Browne asked the Court “to clarify the obligations of States under international law before the clock on our survival runs out. … Antigua and Barbuda stands in solidarity with other vulnerable nations, particularly our fellow small islands. Together, we endure the worst of a crisis we did not cause. But today, we also stand with the millions across the globe who are looking to this Court for a path forward—for clarity, for justice, and for hope. We believe in the power of international law to bring about change.”

Catherine Drummond appeared as counsel for Antigua and Barbuda, instructed by Zachary Phillips, Agent of Antigua and Barbuda before the International Court of Justice and Crown Counsel II of the Attorney General’s Chambers, Ministry of Legal Affairs; and by Sidley Austin in Geneva.