California has implemented ambitious policies to reduce greenhouse gases (GHGs) and air toxins from the transport sector for both passenger vehicles and trucks. Most recently, the Advanced Clean Fleet and Advanced Clean Truck rules mandate a transition to zero emission trucks by 2042 for the entire state. These regulations are based on tailpipe emissions. While reducing tailpipe emissions is critical for reducing the health impacts of emissions on local populations, the operation/use phase is only one phase of the truck life cycle that produces emissions. From a climate change perspective, the emissions generated over the entire life of the truck is a more appropriate measure for GHG reduction.
Life Cycle Assessment (LCA) has been developed for this purpose. There are two types of LCA: environmental LCA (E-LCA) and social LCA (S-LCA). E-LCA looks at inputs (water, electricity, energy) and outputs (GHGs, other emissions/toxins) to calculate a normalized environmental footprint over a product's life. S-LCA analyzes a product's social and socio-economic aspects to identify site-specific supply chain impacts (where the activities occur), both positive and negative, for each phase (material acquisition, transformation, distribution, etc.). Impact categories include health, safety, and working conditions for various stakeholder groups. Taken together, these tools can provide a comprehensive assessment of both environmental and social impacts.
Building on their previous research on E-LCA for heavy-duty trucks, the researchers will conduct a S-LCA analysis to assess the social impacts of battery-electric and fuel cell trucks. This S-LCA research will include all materials and life cycle phases for hypothetical battery-electric and hydrogen electric fuel cell trucks, focusing on the materials required for large batteries and fuel cells. S-LCA will pinpoint “hot spots” of harm across the supply chain. The combined LCA (environmental plus social) will provide a more comprehensive assessment of these alternative fuel trucks and a more informed basis for designing zero emission vehicle policies.