Offers a scientific assessment of the state of current knowledge of the carbon cycle by the world's leading scientists. It gives an introductory overview of the carbon cycle, with multidisciplinary contributions covering biological, physical, and social science aspects. Included are 29 chapters covering: Assessment of carbon - climate - human interactions; A portfolio of carbon management options; Spatial and temporal distribution of sources and sinks of carbon dioxide; and Socio-economic driving forces of emissions scenarios.