• Research scientists, engineers and policy makers working in the following areas: natural gas, energy and alternative fuels, environmental science and engineering, climate change and carbon emissions mitigation, energy economics. • Students at undergraduate and postgraduate levels taking energy, engineering and scientific courses. •New-hires in oil/gas operating and service companies • Government advisors and consultants working on energy and carbon emissions mitigation. Professionals working in science policy. • As is the case for previous books by Smil, this book also has potential to attract broader society interest including politicians, journalists and the educated public looking for a broad understanding of the industry and its issues.