The role of advisory opinions in international law in the context of the climate crisis: an introduction

This introductory chapter of ‘The Role of Advisory Opinions in International Law in the Context of the Climate Crisis’ explores the evolving landscape of international climate law at a pivotal moment marked by a surge in climate litigation and the landmark issuance of advisory opinions by international and regional courts and tribunals. Rooted in the context of decades of climate litigation primarily pursued at domestic levels, the shift to international courts and tribunals highlights an urgent need for clear and enforceable obligations on States to mitigate and adapt to climate change. Central to this inquiry are the Paris Agreement and UNFCCC, whose provisions, while vital, remain ambiguous and largely non-binding, prompting individuals, civil society, and States to seek legal clarity. By examining the growing influence of advisory opinions – including those recently delivered or forthcoming from the ITLOS, IACtHR, and ICJ – the book provides a comprehensive analysis of how international courts can clarify States’ climate obligations. These non-binding opinions, positioned as ‘Rosetta Stones’ for interpreting States’ responsibilities, illuminate a path forward by translating aspirational climate goals into actionable commitments. This chapter introduces the main topics and themes of the book, setting the stage for a critical conversation on the significance of this moment and the role of international law in addressing one of the world’s most urgent challenges.