Replacing a gasoline-powered car with an electric vehicle before the end of its useful life can significantly reduce greenhouse gas emissions over its life cycle, according to a study conducted by American researchers.
Published in a scientific journal, the research concludes that replacing a gasoline SUV with only two years on the road with an electric vehicle, instead of keeping it in service for another 14 years, could nearly halve the carbon footprint of its owner over the vehicle’s lifetime.
The researchers analyzed different scenarios, considering vehicle efficiency, the carbon intensity of electricity grids, and the emissions associated with manufacturing electric vehicles. In all cases, early substitution with an electric vehicle showed emission benefits.
Selling the used car can negate the gains
However, the authors warn that these benefits may disappear if the gasoline car is sold on the used market instead of being permanently withdrawn from circulation.
According to the study, selling these vehicles can increase supply in the second-hand market, lower prices, and extend the use of fossil-fuel-powered cars, offsetting part of the emissions reductions initially achieved.
Therefore, the researchers argue that public policies should encourage the scrapping of gasoline vehicles, accelerating the fleet replacement by electric models.
Results may not be applicable to all countries
Commenting on the study, Ralph Sims, emeritus professor of Sustainable Energy and Climate Change Mitigation at Massey University, New Zealand, says that the conclusions cannot be automatically extrapolated to all countries. “The study shows significant reductions in greenhouse gas emissions from electric vehicles compared with internal combustion engine vehicles, also taking into account emissions across the life cycle,” he says.
However, the researcher notes that in New Zealand, where electricity production is predominantly based on renewable sources, electric vehicles have an even lower carbon footprint than in the United States.
On the other hand, he notes that the country has one of the oldest vehicle fleets in the world, with many cars remaining in service for more than 20 years. “A policy, such as the one suggested by the American study, to subsidize the early retirement of internal combustion engine vehicles makes little sense in New Zealand,” he says.
Nevertheless, Ralph Sims emphasizes that the main conclusion of the investigation remains valid. “The key message of the study is that life-cycle emissions of an electric vehicle are far lower than those of an equivalent internal combustion engine vehicle, especially considering advances in battery recycling technologies,” he concludes.
