This unique and up-to-date book analyses the functioning of the European Emissions Trading Scheme (ETS) and assesses the extent to which relevant legislation has affected its capacity to promote cost-effective reduction of European carbon emissions. The author investigates whether inefficiency has been caused by both the ETS cap setting procedure and by the ETS relevant allocation rule, as defined by Directive 2003/87/EC. He then considers whether the new Directive 2009/29/EC, which reforms the ETS institutional design, is likely to improve the scheme's effectiveness by reducing the risk of carbon leakage - which could potentially be a consequence of implementing a unilateral policy across the asymmetric political landscape of Europe. This well-documented book will appeal to researchers and postgraduate students in environmental law and environmental economics, as well as policymakers within environment, industry and economics, and electric and industrial operators and stakeholders. Environmental NGOs, energy and environmental consulting groups, members of the European Commission, and energy and environmental think-tanks will also find much to interest them in this insightful book.