Climate change, development and development cooperation are, individually and jointly, three politically sensitive, complex issues, especially in the context of relations between developed and developing countries. This book tackles these issues by combining theoretical, political, and practical perspectives, analysing the dominant paradigms and exploring the meaning of the concept of mainstreaming. At the practical level, it presents the results of case studies focusing on assistance provided by the European Union and key member states and the climate needs articulated by developing countries. At the political level, it highlights the sensitivities between developed and developing countries and examines the mainstreaming debate in various fora. This book is valuable for policymakers, academics, politicians and non-state actors working in the fields of development studies, international law, politics, international relations, economics, climate change, and environmental studies.