Exploring the relationships between energy, work, power, and material and social complexity over the last four billion years, this book suggests that in six revolutions this relationship has been fundamental to the trajectory of life on our planet. The stability of this growing complexity has required a parallel hierarchy of homeostatic, regulatory mechanisms, and Gareth Wyn Jones explains the profoundly disturbing implications of these twin hypotheses to the challenges of anthropogenic climate change. He asserts that a recognition of the underlying problems and trends is the beginning of wisdom and a new relationship with energy can enhance human well-being and our interaction with the rest of the natural world.