Abstract

Both the private and public sectors are keenly interested in characterizing opportunities for agricultural greenhouse gas abatement, notably as cost-effective alternatives to fossil fuel based mitigation and alternative farm revenue streams. Economic theory defines marginal abatement costs as the incremental cost of an additional unit of abatement. However, abatement cost analyses to date have struggled with how to capture incremental biophysical responses associated with the sequential or simultaneous adoption of multiple abatement technologies. Yield, soil, and greenhouse gas responses to crop management changes depend critically upon the existing biophysical state. Biophysical process models are uniquely qualified to estimate physical responses associated with incremental adoption of crop management strategies. Using a biophysical process model, we identify incremental least-cost mitigation strategies by sequentially redefining the biophysical state following selection of cost-effective management options given current biophysical conditions. Specifically, we apply the DeNitrification-DeComposition (DNDC) process model in combination with data on option costs, input prices, and output prices, to identify the incremental mitigation potential of crop management options for rice paddies in China. The result is a conceptually appropriate marginal abatement cost curve that truly reflects incremental cost-effective adoption of mitigation alternatives. The analysis allows us to evaluate an important potential bias associated with previous analysis, provide more refined estimates of greenhouse gas mitigation potential, and provide direction for future research on greenhouse gas abatement from crop systems.