Regional Differences in Life-Cycle Greenhouse Gas and Criteria Air Pollutant Emissions of Light-Duty Vehicles in the United States

To facilitate the efforts to identify greenhouse gas (GHG) and criteria air pollutants (CAP, representing CO, VOC, NOx, SOx, PM10 and PM2.5) emission-reduction opportunities that may be specific to particular regions, this paper intends to estimate regional differences in life-cycle GHG and CAP emissions from light-duty vehicles in the US, using the GREET (the Greenhouse gases, Regulated Emissions, and Energy use in Transportation) Model, a life-cycle analysis model that has been developed at Argonne National Laboratory to quantify life-cycle GHG and CAP emissions from both conventional and advanced vehicle/fuel systems. The GHG and CAP emission burdens of upstream crude oil recovery, transportation, refining and distribution activities associated with the production of gasoline and diesel from both domestic and foreign crude oil sources for the US transportation sector are explored in each of the Petroleum Administration for Defense Districts (PADD) regions. Besides, GHG and CAP emission factors of light-duty vehicle operation on the county level are calculated by using EPA’s MOVES model. Results show that the life-cycle GHG and CAP emissions induced by fuel use by both gasoline and diesel light-duty vehicles differ to a varying extent among the PADD regions, due to regional differences in GHG and CAP emissions associated with various life-cycle stages, in PADD-specific crude oil source profiles, and in the vehicle operation emission factors. INTRODUCTION An accurate assessment of current and future advanced vehicle/fuel system options of their energy-saving and emission reduction potentials requires a complete vehicle fuel-cycle analysis, known as a well-to-wheels (WTW) analysis. For this purpose, a WTW analysis of conventional vehicle/fuel systems serves as the comparison basis for accurate evaluation of current and future vehicle/fuel systems within a methodology-and-data consistent framework, and therefore requires scrutinous examination with latest high quality data to reflect the impact of technology advances. Life-cycle analysis (LCA) has become a widely used tool in recent years to estimate environmental effects of the entire life-cycle of transportation vehicle/fuel systems. While the accuracy and level of aggregation of data are essential for credible LCA, regional LCA is