From Moral Duty to Legal Obligation: The ICJ’s Climate Shift

For the first time in history, The International Court of Justice (ICJ) has ruled that doing nothing about climate change may violate international law.

In July 2025, the UN’s highest court delivered an advisory opinion declaring that states have a legal duty to prevent climate harm and to protect both current and future generations. What was once political rhetoric had now become a matter of legal responsibility.

According to the Court, states must act with due diligence; this means cutting emissions, regulating corporations, and cooperating globally to limit warming to 1.5°C. The judges warned that inaction can constitute an “internationally wrongful act”. This obligation stems not only from the Paris Agreement but also from customary international law and fundamental human rights principles, linking the protection of the environment to the right to life, health and self-determination.

The ICJ further stated that the countries breaching these duties may face legal consequences, including reparations for climate-related loss and damage. For small island nations and vulnerable communities already battling rising seas, this offers a potential path to justice and a precedent for future climate litigation.

Yet one question remains: who will enforce it? The ICJ cannot compel compliance. Power politics still decide whether law becomes action. Will major emitters transform promises into policy? Or prove that accountability ends where influence begins?