Climate policy is today a significant area of EU governance, providing important framework conditions for many industries. But how has EU climate policy developed? This book offers structured, comparative case studies of the development of four central climate policies: emissions trading systems, renewables, carbon capture and storage, and energy policy for buildings, examining the intriguing similarities and differences in how these have taken shape. Combining sociological New Institutionalism and political science theories in a novel and engaging way, Elin Lerum Boasson and Jørgen Wettestad explore and explain the history of EU climate policy. What emerges are fascinating stories - of skilled entrepreneurs who have managed to create and exploit political windows of opportunity, and of more long-term path-dependent developments. Drawing on more than 60 interviewees, the authors present accounts never told before, providing a valuable and timely contribution to our knowledge of environmental management and EU integration. This book is a must-read for all those seeking to understand the driving forces in EU climate policy and recognize its prospects for the future.