This book discusses the demise of the unreliable and risk prone use of solid and liquid fossil fuel and the development of a sustainable world energy system which assures environmental quality and an equitable socio-economic system. Although more sources of oil are becoming available, supply of oil is becoming increasingly less secure. Increasing petroleum costs, supply uncertainties, political factors, and environmental damage are forcing a radical move towards alternative fossil fuels such as natural gas and tar sand/shale extracted oil, bio-fuels, and alternative energy sources. This book provides an up-to-date review of the socio-economic, political, and environmental factors forcing a new approach to global energy developments and use, as well as a review of the alternative fuel and energy conversion technology developments which will drive future energy use towards a cleaner, sustainable, and more secure future.