Policy can downsize passenger vehicles and cut climate emissions

Abstract The growing global market share of sport utility vehicles and other light-duty trucks is increasing the carbon and energy intensity of new passenger vehicles—cancelling out some of the benefits of efficiency improvements including electrification. Existing climate regulations can inadvertently support this trend, notably the attribute-based vehicle emissions standards (VES) that have less stringent requirements for larger vehicles. We utilize a model of demand and supply interactions to simulate a VES that is neutral regarding vehicle class and size, as well as a truck purchase tax and electric vehicle efficiency standard. Relative to the attribute-based version, a neutral VES can induce modest but additive reductions in GHG emissions and new vehicle mass. Additional instruments can further reduce vehicle emissions and size, and reduce battery capacity among electric vehicles. In short, careful policy design can help to reduce vehicle upsizing trends while contributing to GHG mitigation.