The adoption of electric vehicles (EVs) might be helping curb pollution in California’s wealthier neighborhoods, but such improvements may be occurring at the expense of disadvantaged communities, a new analysis has found.
Although widespread EV adoption is likely leading to an overall decrease of greenhouse gas emissions, the reduction may be redistributing such pollutants from the vehicles themselves to electric generating units, according to the study, published Wednesday in PLOS Climate.
“Emissions may decrease in some locations and increase in others, with implications for equity,” wrote the authors of the study, led by researchers at the University of California, Berkeley.
To investigate this hypothesis, the authors analyzed the effects of California’s Clean Vehicle Rebate Project from 2010–2021, which has offered rebates from $1,000 to $7,500 for the purchase or lease of eligible zero-emissions vehicles.
They found that the project reduced total statewide emissions of carbon dioxide, nitrous oxides and sulfur dioxide, but that it increased accumulation of fine particulate matter (PM 2.5).
The shift to cleaner cars could be causing an overall boost in PM 2.5 emissions because vehicle electrification only minimally reduces the release of particulate matter, according to the study.
At the same time, the authors explained, as power production facilities work to meet rising energy demands, they may end up emitting increasing quantities of PM 2.5.
In their decadelong analysis, the authors observed not only a rise in PM 2.5 levels, but also that “changes in air pollution are not distributed equally.”
Their results showed that net reductions of primary PM 2.5, nitrous oxide and sulfur dioxide emissions disproportionately occurred in the wealthiest communities.
Among the public health threats associated with increased exposure to air pollutants are elevated cancer risk, cardiovascular disease, respiratory illness, diabetes and diminished school performance among affected children, according to the study.
If the current socioeconomic and demographic distribution of EV rebates remains unchanged, the researchers warned that these inequities will remain — persisting even if the state achieves its goal of 1.5 million zero-emission vehicles by 2025.
The authors expressed hope that their findings could “help policymakers avoid exacerbating the inequitable distribution of environmental burdens in the pursuit of greenhouse gas emissions reductions.”
“Increased uptake of electric vehicles in communities facing the highest air pollution exposure, along with accelerated clean energy generation, could ameliorate associated environmental inequities,” they concluded.