As the contours of a post-2012 climate regime begin to emerge, compliance issues will require increasing attention. This volume considers the questions that the trends in the climate negotiations raise for the regime's compliance system. It reviews the main features of the UN Framework Convention on Climate Change and its Kyoto Protocol, canvasses the literature on compliance theory and examines the broader experience with compliance mechanisms in other international environmental regimes. Against this backdrop, contributors examine the central elements of the existing compliance system, the practice of the Kyoto compliance procedure to date and the main compliance challenges encountered by key groups of states such as OECD countries, economies in transition and developing countries. These assessments anchor examinations of the strengths and weaknesses of the existing compliance tools and of the emerging, decentralized, 'bottom-up' approach introduced by the 2009 Copenhagen Accord and pursued by the 2010 Cancun Agreements.