Chapter 12 - Mitigation Opportunities for Life-Cycle Greenhouse Gas Emissions during Feedstock Production across Heterogeneous Landscapes

Abstract

Feedstock production can contribute ≥50% of the life-cycle global warming intensity (GWI) of a biofuel. Variability exists within and among high-leverage components of the biomass production phase. GWI variability within feedstocks has gone unrecognized by regulatory agencies. We present results of a review and analysis of select feedstock production LCAs. System levers with the most potential to reduce feedstock GWI are N fertilizer use, N 2 O emissions, and tillage impact on soil carbon. The median feedstock GWIs span an order of magnitude from 50 to 500 kg CO 2 e per Mg of feedstock produced. Uncertainty in the GWI of the various LCA components is a function of the methods used and the availability of input data required by the respective methods. Including entity-level measurements of the GWI of feedstock production could incentivize feedstock producers to use lower GWI practices. Results of this study are a starting point from which more rigorous and perhaps regionally specific data on key leverage points and production systems should be collected to help guide biomass producers toward minimizing the GWI of their particular biomass production system.