Air quality impacts from the electrification of passenger vehicles in the U.S.
A central strategy in achieving greenhouse gas mitigation targets is the transition of vehicles from internal combustion engines to electric power. However, due to complex emission sources and nonlinear chemistry, it is unclear how such a shift might impact air quality. Here we apply a prototype version of the new-generation NOAA GFDL global Atmospheric Model, version 4 (GFDL AM4) to investigate the impact on U.S. air quality from an aggressive conversion of internal combustion vehicles to battery-powered electric vehicles (EVs). We examine a suite of scenarios designed to quantify the effect of both the magnitude of EV market penetration and the source of electricity generation used to power them. We find that summer surface ozone (O 3 ) decreases in most locations due to widespread reductions of traffic NO x emissions. Summer fine particulate matter (PM 2.5 ) increases on average and largest in areas with increased coal-fired power generation demands. Winter O 3 increases due to reduced loss via traffic NO x while PM 2.5 decreases since larger ammonium nitrate reductions offset increases in ammonium sulfate. The largest magnitude changes are simulated at the extremes of the probability distribution. Increasing the fraction of vehicles converted to EVs further decreases summer O 3 , while increasing the fraction of electricity generated by “emission-free” sources largely eliminates the increases in summer PM 2.5 at high EV adoption fractions. Ultimately, the number of conventional vehicles replaced by EVs has a larger effect on O 3 than PM 2.5 , while the source of the electricity for those EVs exhibit greater control on PM 2.5 .