In California, concern about greenhouse gas (GHG) emissions has increased in recent years as it has become apparent that California’s climate is changing due to increases in GHG emission rates. It is therefore imperative that comprehensive assessments of the biophysical and economic potential for C sequestration and mitigation of trace gas (i.e. N₂O and CH₄) emissions in California are conducted. Therefore, our overall objective is to assess the biophysical potential and economic feasibility for soil C sequestration and reduction of trace gas emissions in California agricultural soils through the integration of spatial databases on environmental factors and land use data with ecosystem simulation models and economic analyses. The integrated assessment is being accomplished by directly linking an ecosystem model calibrated for California conditions with an economic model that has been extensively used to assess sustainable agricultural practices. The ecosystem model will provide greenhouse gas mitigation supply curves based on estimates of changes in soil C, trace gas fluxes, and productivity (yield) based on soil, climate and management data. The ecosystem model outputs will then serve as input into the economic model. Uncertainties associated with this model-based assessment will be evaluated using an empirically based method to consider the structural inaccuracies in model simulations and an ensemble approach to consider model input error. This decision-support assessment tool will provide a more complete accounting structure for land use and management impacts on C stocks and associated CO₂, N₂O and CH₄ fluxes between California agricultural soils and the atmosphere.

For more information contact Johan Six (jwsix@ucdavis.edu) or Steven De Gryze (sdegryze@ucdavis.edu).