This book focuses on the developing role that the city currently plays in dealing with the effects of climate change and the instruments that can be utilised to make them truly green. Cities are at the centre of European directives aimed at tackling climate change, representing a key part of the European Green Deal and the National Recovery and Resilience Plans. As such, they provide valuable case studies for other countries grappling with how to address sustainability issues. This book is divided into three parts, with the first analysing the intersection of economics and urban sustainability demands. The second examines various thematic aspects relating to this intersection, looking at the National Recovery and Resilience Plans, the law of the city and environmental issues. The third and final part presents case studies from four European cities showing how they are facing this transformation. These include Bologna, Paris, Barcelona and Valencia, chosen as European Green City 2024 because of its exemplary transition. Bringing together leading experts, some of whom have been directly involved in developments, the book presents invaluable comparisons that will be of interest to a wider international readership. The book will be of interest to academics, researchers and policy-makers working in the areas of Public Law, Environmental Law and Urban Law and Governance.