This book explores the integration of long-term climate policy objectives into EU energy policy. It engages in-depth empirical analysis on the integration of climate policy objectives into renewable energy policy; energy performance of buildings; and policies in support of natural gas importing infrastructure. The book describes insufficient levels of climate policy integration across these areas to achieve the long-term policy goals. A conceptual framework to find reasons for insufficient integration levels is developed and applied. This book is a valuable resource for students, researchers, academics and policymakers interested in environmental, climate change and energy policy development in the EU, particularly from the perspective of long-term policy challenges. The book adds to scholarly literature on policy integration and EU integration, and contributes to new and developing research about EU decarbonisation.