What if we told you that, from an environmental point of view, it would be better to scrap your diesel or petrol car and replace it with an electric one even if you just bought it?
This is the surprising conclusion reached by a study published in Sciencewhich analyzed the carbon footprint of replacing one car with another in the United States. “Replacing an internal combustion engine vehicle with a battery electric vehicle almost always reduces greenhouse gas emissions,” says Roland Geyer, one of the two authors of the research.
When talking about the ecological footprint of electric vehicles, we must take into account not only the emissions linked to production (especially the battery), but also those linked to the electricity used to power them, which if it comes from renewable sources has zero impact, but if it comes from fossil sources it pollutes. Added to this are the environmental costs of recycling batteries at the end of their life.
When is it best to go electric?
Even taking all these aspects into account, numerous studies have shown that electric vehicles have a significantly lower carbon footprint than internal combustion vehicles. The aspect that had never been investigated until now was what was the best time to go electric to maximize climate benefits.
The two researchers tried to answer this question, starting from some comments collected in a previous project: “Some people thought it was more sustainable to keep their car until it was time to scrap it, and others were uncertain about the best time to replace it”, explains Elliott Campbell, coordinator of the study.
The study
The two authors analyzed over 400 models of internal combustion and electric vehicles, considering their efficiency, the source from which the electricity that powers them comes, the mileage and the emissions linked to the production of the batteries. The results indicate that the greatest climate benefit is obtained by scrapping the petrol or diesel car in the first year of use and replacing it with an electric one, with a 58% reduction in carbon emissions over a 16-year period compared to keeping the car internal combustion for its entire useful life.
Exceptions that prove the rule
The benefits of substitution vary based on location and type of vehicle (remember that the study was conducted in the USA), but in 92% of the cases analyzed there was still a reduction in carbon emissions. A notable exception concerns plug-in hybrid vehicles: as they are already efficient, replacing them early with an electric one can in some cases increase emissions rather than reduce them.
Likewise, it is not worth replacing a petrol vehicle that we drive for less than 7,000 km a year.
Finally, the composition of the energy mix of the local electricity grid also has an impact: where electricity depends heavily on coal or other fossil sources, the benefit of substitution is reduced. However, for the best-selling gasoline car models in the United States, early replacement results in reduced emissions even on the dirtiest power grids. About 50% of the electricity we use in Italy comes from renewable sources – a decidedly better situation than many areas of the United States which, therefore, makes the switch to electric even more ecologically advantageous.
