This book uses environmental disputes as a focus to develop a novel comparative analysis of the functions of international adjudication. Paine focuses on three challenges confronting international tribunals: managing change in applicable legal norms or relevant facts, determining the appropriate standard and method of review when scrutinising State conduct for compliance with international obligations, and contributing to wider processes of dispute settlement. The book compares how tribunals manage these challenges across four key sites of international adjudication: adjudication in the World Trade Organization and under the United Nations Convention on the Law of the Sea, International Court of Justice litigation, and investment treaty arbitration. It shows that while international tribunals perform several key functions in the contemporary international legal order, they are subject to significant constraints. Paine makes a genuine addition to literature on the role of international adjudication in international law which will benefit academics, practitioners, and policymakers.