The global carbon cycle : integrating humans, climate, and the natural world / Current status and past trends of the global carbon cycle / The vulnerability of the carbon cycle in the 21st century : an assessment of carbon-climate-human interactions / Scenarios, targets, gaps, and costs / A portfolio of carbon management options / Interactions between CO₂ stabilization pathways and requirements for a sustainable Earth system / A paleo-perspective on changes in atmospheric CO₂ and climate / Spatial and temporal distribution of sources and sinks of carbon dioxide / Non-CO₂ greenhouse gases / Climate-carbon cycle interactions / Socioeconomic driving forces of emissions scenarios / Natural processes regulating the ocean uptake of CO₂ / Variability and climate feedback mechanisms in ocean uptake of CO₂ / A primer on the terrestrial carbon cycle : what we don't know but should / Geographic and temporal variation of carbon exchange by ecosystems and their sensitivity to environmental perturbations / Current consequences of past actions : how to separate direct from indirect / Pathways of atmospheric CO₂ through fluvial systems / Exchanges of carbon in the coastal seas / Pathways of regional development and the carbon cycle / Social change and CO₂ stabilization : moving away from carbon cultures / Carbon transport through international commerce / Near- and long-term climate change mitigation potential / Unanticipated consequences : thinking about ancillary benefits and costs of greenhouse gas emissions mitigation / International policy framework on climate change : sinks in recent international agreements / A multi-gas approach to climate policy / Storage of carbon dioxide by greening the oceans? / Direct injection of CO₂ in the ocean / Abatement of nitrous oxide, methane, and the other non-CO₂ greenhouse gases : the need for a systems approach