A comprehensive, systematic, analytically unified, and interdisciplinary treatment of energy in nature and society, from solar radiation and photosynthesis to our fossil fuelled civilization and its environmental consequences. Energy in Nature and Society is a systematic and exhaustive analysis of all the major energy sources, storages, flows, and conversions that have shaped the evolution of the biosphere and civilization. Vaclav Smil uses fundamental unifying metrics (most notably for power density and energy intensity) to provide an integrated framework for analyzing all segments of energetics (the study of energy flows and their transformations). The book explores not only planetary energetics (such as solar radiation and geomorphic processes) and bioenergetics (photosynthesis, for example) but also human energetics (such as metabolism and thermoregulation), tracing them from hunter-gatherer and agricultural societies through modern-day industrial civilization. Included are chapters on heterotrophic conversions, traditional agriculture, preindustrial complexification, fossil fuels, fossil-fueled civilization, the energetics of food, and the implications of energetics for the environment. The book concludes with an examination of general patterns, trends, and socioeconomic considerations of energy use today, looking at correlations between energy and value, energy and the economy, energy and quality of life, and energy futures. Throughout the book, Smil chooses to emphasize the complexities and peculiarities of the real world, and the counterintuitive outcomes of many of its processes, over abstract models. Energy in Nature and Society provides a unique, comprehensive, single-volume analysis and reference source on all important energy matters, from natural to industrial energy flows, from fuels to food, from the Earth's formation to possible energy futures, and can serve as a text for courses in energy studies, global ecology, earth systems science, biology, and chemistry.