Law as Provocation: the ICJ’s 2025 Advisory Opinion on the Obligations of States in Respect of Climate Change

The International Court of Justice’s (ICJ) 2025 advisory opinion on climate change marks a significant expansion of international law into the governance of global public goods. By framing climate inaction as a potential violation of international law and human rights, the Court advances a progressive legal agenda that extends beyond existing political consensus and enforcement capacity. This article develops a realist critique of the ruling that avoids both legal romanticism and nihilism. It argues that the opinion cannot compel state compliance in an anarchic system characterized by sovereignty, power asymmetries, and strategic interests, and that excessive judicial ambition may risk undermining institutional credibility. At the same time, the article contends that, in the context of climate change as an existential risk, normative ambition by international courts can be strategically consequential. The ICJ’s climate opinion functions less as enforceable law than as a mechanism for reshaping legitimacy, empowering litigation and civil society, and increasing the political costs of inaction. The ruling thus reveals a central paradox of international law under realism: law cannot govern without power, yet it can still influence power by redefining the terms of political contestation.