Electric cars outperform gasoline cars in lifetime environmental impact

Over two years of use, lithium-ion battery electric vehicles (BEVs) emit less cumulative carbon dioxide (CO₂) than fossil fuel-powered internal combustion engine (ICE) cars, according to a new study published this week in the open access journal PLOS Climate by Pankaj Sadabarte of Duke University and colleagues.

The transportation sector accounts for 28% of U.S. greenhouse gas emissions, and there is a growing consensus in favor of electric vehicles to address climate and air quality challenges. However, debate continues as to whether lithium-ion batteries are truly clean when considering the entire manufacturing and operational lifecycle.

In the new study, researchers used the Global Change Analysis Model (GCAM) Integrated Assessment Model to assess CO₂ and air pollutant emissions across four scenarios in which electric vehicle penetration increases in the United States through 2050. The analysis included emissions from fuel production, battery manufacturing, vehicle assembly, and operation for both electric and gasoline vehicles.

The study concludes that when all lifecycle factors are considered, electric cars produce 30% more CO₂ emissions than gasoline cars during the first two years of operation. Higher initial emissions result from the energy-intensive lithium mining and battery manufacturing processes. However, after the second year on the road, electric vehicles begin to reduce cumulative emissions compared to gasoline alternatives.

Additionally, as battery power increases over time, each additional kWh of lithium-ion battery power reduces an average of 220 kg of CO₂ in 2030 and 127 kg of CO₂ in 2050. Considering the effects of air pollution and climate change, the economic value of environmental damage over the lifetime of an ICE vehicle is currently 2-3.5 times that of a BEV.

Co-author Dr. Drew Schindell summarizes, “When considering both climate and air quality, internal combustion engine vehicles cause about two to three times more damage than EVs.”

The authors note that several assumptions were made regarding passenger vehicle range, vehicle lifespan, and average passenger vehicle battery size in the United States. Furthermore, this study does not take into account the associated emissions caused by the infrastructure needed to meet increasing charging demand. However, they conclude that the relative advantage of BEVs is expected to increase in coming decades as electricity generation becomes cleaner due to reduced fossil fuel usage.

Lead author Dr. Sadabarte added: “Our study shows that the transition from fossil fuel vehicles to battery electric vehicles (BEVs) has the potential to significantly improve climate and air quality over time.

“Although BEVs initially have higher lifecycle emissions due to mining and battery production, analysis using global change analysis models demonstrates that they can quickly outperform internal combustion engine vehicles, reduce carbon emissions, and reduce harmful air pollutants. As the U.S. power grid becomes cleaner, the economic and environmental benefits of BEVs will become even stronger.”