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

This briefing examines the impact of the International Court of Justice (ICJ) Advisory Opinion on the Obligations of States in Respect of Climate Change on international investment law, arguing that climate action is now a binding legal obligation that should inform the interpretation of investment treaties and investor-state dispute settlement (ISDS) claims.

• The International Court of Justice (ICJ) has established that climate action is a binding legal obligation under international law rather than a discretionary policy choice. This means that investment law and climate obligations are on the same legal footing, and failing to take appropriate measures could be considered an internationally wrongful act.
• The ICJ's ruling challenges the basis of ISDS claims where investors argue that climate measures, such as coal phase-outs or drilling bans, breach investment protections. Common standards used in these claims—including fair market value for compensation, protection against expropriation, and fair and equitable treatment—can now be challenged because investment treaties must be interpreted in light of binding climate obligations.
• The document recommends several actions for states to align investment governance with climate action: creating a plurilateral climate change 'carveout' from ISDS for fossil fuel investments, restricting forward-looking damages that rely on speculative future revenues, terminating outdated investment treaties and their sunset clauses, and pursuing a fundamental reform of the international investment regime.

APA

Schaugg,, L. (2026). What Does the International Court of Justice Advisory Opinion on Climate Change Mean for International Investment Law? International Institute for Sustainable Development. https://www.iisd.org/publications/brief/icj-advisory-opinion-international-investment-law

Chicago

Schaugg,, Lukas. What Does the International Court of Justice Advisory Opinion on Climate Change Mean for International Investment Law? International Institute for Sustainable Development, 2026. https://www.iisd.org/publications/brief/icj-advisory-opinion-international-investment-law.

Wikipedia

{{cite report |last1=Schaugg, |first1=Lukas |title=What Does the International Court of Justice Advisory Opinion on Climate Change Mean for International Investment Law? |publisher=International Institute for Sustainable Development |date=17 March 2026 |url=https://www.iisd.org/publications/brief/icj-advisory-opinion-international-investment-law |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{schaugg2026what, author = {Schaugg,, Lukas}, title = {{What Does the International Court of Justice Advisory Opinion on Climate Change Mean for International Investment Law?}}, institution = {International Institute for Sustainable Development}, year = {2026}, month = mar, url = {https://www.iisd.org/publications/brief/icj-advisory-opinion-international-investment-law}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }