A huge increase in energy use is expected in the coming decades - see the IEA's 'business as usual'/reference scenario below. While developed countries could use less energy, a large increase is needed to lift billions out of poverty, including over 25% of the world's population who still lack electricity. Meeting demand in an environmentally responsible manner will be a huge challenge. The World Bank estimates that coal pollution leads to 300,000 deaths in China each year, while smoke from cooking and heating with biomass kills 1.3 million world-wide - more than malaria. The IEA's alternative scenario requires a smaller increase in energy use than the reference scenario and is also less carbon intensive, but it still implies that CO2 emissions will increase 30% by 2030 (compared to 55% in the reference scenario). Frighteningly, implementing the alternative scenario faces "formidable hurdles" according to the IEA, despite the fact that it would yield financial savings for consumers that far exceed the initial additional investment cost. I shall give an overview of the energy outlook and the portfolio of technological and economic measures that are need to meet the energy challenge and do better than the alternative scenario.