Early switch to EVs delivers significant climate benefits
Continuing to drive a functional combustion-engine car rather than replacing it with an electric vehicle is not necessarily the more climate-friendly option. A US study finds that switching to an electric car reduces emissions in 92 per cent of the modelled scenarios.
A study by researchers at the University of California Santa Cruz (UCSC) finds that switching early from an internal combustion engine vehicle to a battery-electric car almost always significantly reduces CO₂ emissions. However, this requires the ICE vehicle to be scrapped rather than resold, as continued use would still generate CO₂ emissions. As a result, replacing even a one-year-old petrol car with an electric vehicle can reduce CO₂ emissions. The researchers did not investigate whether such an early switch is financially beneficial for the driver.
For the study, published in the scientific journal Science, the researchers analysed more than 400 vehicle scenarios. They considered factors including fuel efficiency, battery size, annual mileage and regional electricity mixes, with a focus on the US. In 92 per cent of the modelled scenarios, switching to an electric car as early as possible was more climate-friendly than continuing to use an ICE vehicle. The longer an ICE vehicle remains in use, the more CO₂ it emits.
According to the study, an electric car typically offsets the additional CO₂ emissions from vehicle and battery production after around three years, after which its overall carbon footprint becomes lower than that of an ICE vehicle. Manufacturers are increasingly working to reduce this initial CO₂ burden. For example, BMW states that the iX3 achieves a lower CO₂ footprint after 21,500 kilometres than a comparable ICE vehicle. At an annual mileage of 11,000 kilometres, it would reach this point after around two years.
Once an electric car has offset the additional CO₂ emissions from its production, its greenhouse gas advantage over comparable petrol or diesel vehicles grows rapidly. Even if the replaced ICE vehicle is only one or two years old, switching to a battery-electric model can reduce lifecycle emissions by up to 44 per cent. However, this requires the replaced ICE vehicle to be scrapped rather than sold.
The study’s authors, J. Elliott Campbell and Roland Geyer, emphasise that these findings strongly support the sustainability of electric vehicles. Campbell notes that the result ‘makes the sustainability case for EV ownership crystal clear.’ At the same time, he warns that ‘the rate of climate action needs to accelerate too.’
According to the study, the environmental benefit of scrapping an ICE vehicle and buying a new electric car is largely independent of annual mileage. Even drivers who cover relatively few kilometres reach the point at which switching becomes beneficial relatively quickly. The advantage may be smaller or disappear in regions with a highly coal-dependent electricity mix, while charging electric cars with renewable electricity is already widespread in Europe.
The researchers also highlight the used car market as a critical factor. The climate benefits diminish if an ICE vehicle that would otherwise have been taken out of service returns to the road. Nevertheless, the study concludes that focusing solely on the remaining useful life of an ICE vehicle overlooks the potential emissions benefits of switching to an electric car early.