Energy is probably the defining topic of our age. Uncertainty over the long-term availability of some hydrocarbons and nuclear fuels are increasingly prompting volatility in energy prices on world markets. Meanwhile, no serious scientist doubts that the unabated atmospheric emissions of carbon dioxide associated with traditional forms of energy use are (at very least) exacerbating natural variations in climate in undesirable ways. For either reason or both, few commentators of any stature argue that "do nothing" is a credible option in the world of energy management. The technical challenges are legion; yet energy is just as much a socio-economic issue. Surprisingly, there are no authoritative books giving an overall introduction to energy for general readers, students, engineers, geographers or architects, offering adequate coverage of the scientific, engineering, environmental, social and economic dimensions in a single, reasonably-sized and easily-readable volume. The book proposed here seeks to fill that gap. All That Matters about energy. All That Matters books are a fast way to get right to the heart of key issues.