Estimating Potential Economic Net Carbon Flux from U.S. Agriculture Using a High Resolution, Integrated, Socioeconomic-Biogeophysical Model

Estimation of the carbon abatement potential of a national carbon market upon U.S. agricultural lands is needed by climate analysts, policymakers, and carbon market brokers. A high resolution, integrated, socioeconomic-biogeophysical model is developed in this research by linking the economics of land management with spatial data on soils and land use. The economic component of the model functions at the county level with biophysical data at the sub-county level of resolution.

The model is used to estimate changes in net carbon flux induced by incentives for conservation tillage on nine major crops. The economic potential reduction in net carbon flux at incentives of $500 per metric ton carbon (MtC) is estimated to be 18.92 million metric tons carbon (MMtC) below baseline, and 12.6 MMtC below baseline at an offered incentive of $125 per MtC.

Results indicate that the Northern Great Plains, northern Corn Belt, and Mississippi Delta have the greatest economic potential for carbon abatement. Regions with significant amounts of acreage in hay have the greatest potential for gains in net soil carbon. Application of incentives based on soil sequestration potential leads to “leakage” in some regions where land is reallocated from low input practices to higher input practices.

This analysis created an ideal opportunity to study the interactions of data resolution and analytical scale. When analyzing carbon abatement at the national scale, abatement estimations were similar using either high or low resolution data. But, if regional estimation is a goal, the geographic resolution of data must match or surpass the geographic scale of analysis, otherwise estimation errors will be large. Although validation using field-level data indicates that model results are not appropriate for fieldlevel estimation, it also indicates that the high resolution methodology developed here results in much smaller errors than lower resolution versions.

Results indicate that there are many challenges to implementation, but if policymakers decide to implement a carbon abatement program using conservation tillage, either through a market-based mechanism or through government ‘green payments’, the methodology developed here could help reduce uncertainty in estimating regional abatement quantities.