IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group III: Mitigation of Climate Change Energy supply

Global primary energy use almost doubled from 5,363 Mtoe (225 EJ) in 1970 to 11,223 Mtoe (470 EJ) in 2004, with an average annual growth of 2.2% over this period. Fossil fuels accounted for 81% of total energy use in 2004 – slightly down from the 86% more than 30 years ago, mainly due to the increase in the use of nuclear energy. Despite the substantial growth of non-traditional renewable forms of energy, especially wind power, over the last decade, the share of renewables (including traditional biomass) in the primary energy mix has not changed compared with 1970 (see Chapter 4, Section 4.2).