This Energy Report presents a possible transition to a global, sustainable energy system. The two-part report contains a detailed analysis and scenario created by Ecofys, and a narrative by WWF. It addresses the fundamental question: 'Is a fully sustainable global energy system possible by 2050?' The scenario in this report takes a holistic approach to all aspects of energy use across the entire world and each possible means of supplying this energy from sustainable sources. It finds that by utilising today’s technologies alone, 95% of all energy can be renewable by 2050, comfortable lifestyles can be developed and sustained and long-term benefits can outweigh short-term costs.The Energy Report provides the elements needed for this transition.