The United Kingdom is committed to reducing its greenhouse gas emissions by at least eighty per cent by 2050, a target that will only be achieved by transforming the way that energy is supplied and used. At the same time there are anxieties about the security of energy provision in terms of European dependency on natural gas and the reliability of electricity supply. This book explores in detail those factors which could help or hinder the attainment of the UK's climate change targets, and how these factors interact with the parallel objective of maintaining a robust and secure energy system. The book is the result of a major national energy research effort by the UK Energy Research Centre, which includes some of the UK's leading energy experts. The results and recommendations are essential reading for policymakers, professionals, researchers, and anyone concerned with achieving large-scale reductions in carbon emissions, both from the UK and internationally.