The majority of the world's largest carbon emitters are either federations or have adopted systems of decentralised governance. The realisation of the world's climate mitigation objectives therefore depends in large part on whether and how governments within federal systems can cooperate to reduce carbon emissions and catalyse the emergence of low-carbon societies. This volume brings together leading experts to explore whether federal or decentralised systems help or hinder efforts to mitigate and adapt to climate change. It reviews the opportunities and challenges federalism offers for the development and implementation of climate mitigation and adaption policies and identifies the conditions that influence the outcomes of climate governance. Including in-depth case studies of 14 different jurisdictions, this is an essential resource for academics, policymakers and practitioners interested in climate governance, and the best practices for enhancing climate action. This title is also available as Open Access on Cambridge Core.