Smil, in a presentation marked by balance and clarity, synthesizes the field of science dealing with the biosphere. It is an interdisciplinary one, combining organic chemistry, geology, solar physics, microbiology, zoology, and more. Whatever characteristics the biosphere displays on a global scale depend on living matter's fundamental chemistry, so Smil diagrams the structural backbone of cells — molecules such as cellulose or DNA. Moving next through types of metabolism, such as the ATP cycle, Smil explains the resultant chemical products and how they become fixed or cycled through the ground, water, or atmosphere. Addressing concerns about human influences on the biosphere, Smil describes them, but he is a scientist to the core (at the University of Manitoba) and is hesitant to proclaim doom as the certain outcome. That scientific humility only enhances Smil's work. A superior, comprehensive survey.