Estimating Fossil Energy-based CO2 Emissions from U.S. Croplands
DOE supports research to understand mechanisms of carbon sequestration in managed ecosystems. An important part of that research is knowing the sources of carbon emissions. Scientists from Oak Ridge National Laboratory report a method to estimate both on- and off-site fossil energy-based CO2 emissions (FCE) associated with crop production. FCE was found to differ by crop and region because of changes in energy requirements for crop production driven by environmental differences (e.g., soil texture, soil chemistry, and climate). Changes in policies (e.g., farm bills) and abrupt changes in annual weather patterns (e.g., droughts and wet years) have also resulted in annual shifts in FCE. This new method is important because estimates of fossil-fuel consumption for cropping practices and the associated CO2 emissions enable (1) monitoring of energy and emissions with changes in land management and (2) calculation and balancing of regional and national carbon budgets.
Nelson, R.G., C.M. Hellwinckel, C.C. Brandt, T.O. West, D.G. De La Torre Ugarte, G. Marland. 2009. Energy Use and Carbon Dioxide Emissions from Cropland Production in the United States, 1990-2004. Journal of Environmental Quality 38: 418-425.