What Does the International Court of Justice Advisory Opinion on Climate Change Mean for Multilateral Environmental Agreements?

Before the International Court of Justice (ICJ) delivered its landmark Advisory Opinion on the Obligations of States in Respect of Climate Change, cooperation on integrated implementation of climate-related provisions across different MEAs was largely discretionary. Now, evidence of systemic and mutually reinforcing actions will serve to assess due diligence and, ultimately, compliance with international law. 

The court’s findings indicate that countries must take into account climate-related impacts, drivers, and duties when implementing their obligations under MEAs such as the Convention on Biological Diversity or the UN Convention to Combat Desertification, among other treaties. At the same time, any assessment of a state’s compliance with its obligations under the climate regime must be informed by its efforts to protect biodiversity, land, oceans, and human rights. 

This means that poorly coordinated MEA implementation now comes with greater legal and reputational consequences. The ICJ has provided critical guidance on how to design coherent climate and sustainable development policies that are robust, interdependent, mutually reinforcing, and compliant with international law. 

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 climate adaptation, environmental impact assessments, environmentally harmful subsidies, and international investment law.