A spatial modeling framework to evaluate domestic biofuel-induced potential land use changes and emissions

Area of Science:

• Environmental Science
• Agricultural Economics
• Climate Change Research

Background:

• Biofuel production can lead to significant land-use change (LUC) and associated carbon dioxide (CO2) emissions.
• Accurate estimation of these impacts is crucial for sustainable energy policy and climate change mitigation.
• Existing methods often lack a consistent, high-resolution approach to modeling LUC and emissions.

Purpose of the Study:

• To develop and apply a novel bottom-up methodology for estimating biofuel-induced LUC and CO2 emissions in the U.S. from 2010 to 2022.
• To assess the impact of different biofuel production scales and feedstock types (corn, Miscanthus, Switchgrass) on LUC and emissions.
• To provide probabilistic assessments of LUC and emissions at county, state, and national levels.

Main Methods:

• Integrated four components: land availability, land suitability, LUC decision-making, and induced CO2 emissions.
• Utilized high-resolution geospatial data (Cropland Data Layer, Protected Areas Database) and biophysical crop growth models (CERES-Maize, BioCro).
• Employed a county-level stochastic partial-equilibrium model and derived carbon factors from the National Biomass and Carbon Dataset.

Main Results:

• Estimated average total LUC emissions varied significantly across scenarios, ranging from 1.0 to 6.1 gCO2e/MJ.
• Scenarios utilizing dedicated energy crops (Miscanthus × giganteus and Switchgrass) generally resulted in lower LUC emissions compared to corn-based ethanol production.
• Probabilistic assessments provided insights into LUC and emissions under different macroeconomic conditions and biofuel production targets.

Conclusions:

• The bottom-up approach provides a robust framework for evaluating the environmental footprint of biofuel production.
• Dedicated energy crops offer a potentially more sustainable alternative to corn for large-scale biofuel production regarding LUC emissions.
• Policy decisions regarding biofuel targets should consider the differential impacts of feedstock choices on land use and climate change.