This textbook offers a student-friendly survey of the global politics of the environment through the prism of security studies. This book is divided into three thematic sections. The first part sets out the key theoretical and practical arguments for and against bringing together environmental and security issues. The second part examines why environmental issues have been framed by some as ‘national security‘ concerns in the context of the effects of overpopulation, resource depletion, climate change and the role of the military as both a cause and a solution to problems of pollution and natural disasters. Finally, the third section explores the case for treating the key issues of environmental change as matters of human security. The chapters have been updated to include the 2015 Paris Climate Change Accords, the Trump and Sendai Framework for Disaster Risk Reduction, and there is a new chapter on environmental history. Overall, the book provides a clear, systematic and thorough overview of an area of great academic and ‘real-world’ political interest. This book will be essential reading for students of environmental studies, critical and human security, human geography, development studies, and International Relations in general.