Once seen as a collection of individual components, nature is now regarded as a unified system--a biosphere that permeates the Earth's waters and extends from parts of its crust up into the atmosphere. In "Cycles of Life," Vaclav Smil describes current efforts to take into account the complex interplay of living organisms and environmental changes that shape the functioning of biogeochemical cycles. He focuses on the effects of human interference in these cycles caused by actions ranging from the combustion of fossil fuels to feeding a growing population. As we discover how intricate biospheric cycles are, and see the large-scale consequences that a seemingly local change can have, we realize the valuable contributions biogeochemical studies can make to the future of our planet. Based on the latest scientific research, "Cycles of Life" is an authoritative introduction to the workings of the biosphere, one that emphatically calls for thoughtful environmental management, yet remains sensible in its recommendations for preventing further environmental damage.