Defining State Obligations In A Warming World: The ICJ's Advisory Opinion On Climate Change

On 23 July 2025, the International Court of Justice ("ICJ") delivered its long-awaited Advisory Opinion on Climate Change. The Court noted that climate change—driven primarily by anthropogenic greenhouse gas ("GHG") emissions—poses grave risks to humanity and the environment, and opined that States are subject to binding obligations under international treaties (e.g. the UNFCCC, Kyoto Protocol, and Paris Agreement), customary international law, and human rights law to mitigate climate change, cooperate and implement adaptation measures. This Advisory Opinion represents a milestone in international law, where climate change takes the spotlight. While it has direct implications for States, in recognising their regulatory role as part of discharging their international law obligations, it also has ramifications for private actors across all sectors, both as the subject of such regulation and in an increased risk of climate-change related litigation.