What Does the International Court of Justice Advisory Opinion on Climate Change Mean for Climate Adaptation?

Climate change adaptation is one of the core pillars of the international climate regime. It is the process of preparing for, and adjusting to, actual or expected impacts associated with climate change. The country-driven, context-specific nature of adaptation means that it is commonly thought that countries have broad discretion over how and to what extent they engage in adaptation planning and implementation. 

However, in its Advisory Opinion on the Obligations of States in Respect of Climate Change, the International Court of Justice (ICJ) made it clear that engaging in adaptation planning processes and implementing adaptation actions is a binding obligation under climate treaties and customary international law, not just a domestic policy choice. 

While countries continue to have discretion over how adaptation is planned and implemented based on their unique risk and national circumstances, they must demonstrate they have exercised due diligence to prevent and address foreseeable climate harm. This includes enacting appropriate adaptation measures in a timely manner, making decisions according to the best available science, and accounting for climate-related human rights risks—particularly among vulnerable populations. 

This brief is part of a five-part series that seeks to help states understand their legal obligations under the ICJ Advisory Opinion and what actions they can take to ensure compliance. Other areas covered include environmental impact assessments, environmentally harmful subsidies, international investment law, and multilateral environmental agreements.