Keith Paustian is Professor of Soil Ecology in the Department of Soil and Crop Sciences and Senior Research Scientist at the Natural Resources Ecology at Colorado State University. He received his bachelor’s and master’s degrees at Colorado State University and his PhD in Systems Ecology at the Swedish University of Agricultural Sciences in Uppsala. His main fields of interest include agroecosystem ecology, soil organic matter dynamics, global change and greenhouse gas mitigation. He is currently leading projects to elucidate the factors and processes controlling soil organic matter dynamics and to develop better methods to measure and predict changes in soil carbon as a function of management and environmental variables. His research also involves development of ecosystem and economic assessments to advise policy makers on climate change mitigation. Together with other scientists at NREL he is working on estimating soil greenhouse gas emissions for the US national inventory reporting to the UNFCCC and has led the development of the agricultural component of the national accounting system for voluntary reporting of greenhouse gas mitigation, in the 1605B program administered by the Department of Energy. He is currently leading research in 11 developing countries to elucidate the factors and processes controlling soil carbon dynamics and soil greenhouse gas emissions and to develop better methods to measure and predict changes in soil carbon as a function of management and environmental variables. He is serving as Coordinating Lead Author for the 2006 Revised IPCC Guidelines for National Greenhouse Gas Inventory Methods and is a member of the Scientific Steering Committee for the US Carbon Cycle Science Program.