Science is central to understanding most environmental problems and the solutions proposed to remedy them. But environmental issues are highly emotive, attracting extremists from across the political spectrum even in the rarified air of international politics. This book seeks to explain what 'science' and 'politics' are in the context of environmental policymaking and how the interplay of science and politics influences international environmental policy. It uses original case studies to explore the interaction of science and politics across a wide range of international environmental issues including climate change, transboundary conflicts, and international forest management. Many of the chapters are collaborations between scholars from the natural and social sciences, offering a unique combination of perspectives on common environmental challenges worldwide.