A study published in Science reveals that scrapping a petrol car within its first year and switching to a battery electric vehicle (EV) can cut emissions by 58% over 16 years, achieving carbon payback in about three years. However, the emissions reduction does not apply uniformly, especially for hybrids, low-mileage vehicles, or areas with high-carbon electricity generation.
- 58% emissions cut over 16 years by scrapping petrol cars early for EVs
- Carbon payback occurs in approximately three years after EV adoption
- Exceptions include hybrids, low mileage, and high-emission electricity grids
What happened
A recent study published in the journal Science examined the environmental impact of replacing petrol cars with battery electric vehicles (EVs) early in their lifecycle. Researchers Elliott Campbell and Roland Geyer analyzed data on more than 400 vehicle models, comparing combustion engines and electric vehicles while factoring in variables like grid power mix, mileage, manufacturing emissions, and battery size. The findings indicate that scrapping a petrol car within its first year and substituting it with an EV reduces overall emissions by 58% over a 16-year period.
The research highlights that the carbon payback period—the time it takes for an EV’s reduced operational emissions to offset its higher manufacturing emissions, including the battery—is about three years. Importantly, retiring means scrapping the petrol vehicle to prevent continued emissions, not simply passing it to another user, which would merely transfer emissions elsewhere rather than eliminating them.
Why it matters
These findings provide a more nuanced understanding of the climate benefits of EV adoption, demonstrating significant emissions cuts from early retirement of petrol cars. However, the study underscores exceptions where this benefit diminishes or reverses. For example, efficient hybrids and plug-in hybrids already offer low emissions, so premature replacement with EVs might increase emissions in some cases.
Additionally, vehicles driven less than approximately 4,300 miles per year do not achieve a carbon payback from replacement, since their operational emissions savings are too minimal. The carbon intensity of the local electricity grid also plays a critical role; charging EVs in areas with high emissions grids (more than 970 lbs of CO2 per megawatt-hour) can erode climate benefits. This regional variability is particularly relevant in Europe, where grid cleanliness varies widely between countries.
What to watch next
The policy implications of this research center on promoting scrappage schemes rather than encouraging resale of used petrol cars, to ensure the environmental gains from EV adoption are fully realized. Incentives that pay people to destroy older petrol vehicles could accelerate fleet decarbonization by removing these cars from circulation entirely rather than extending their life via secondary markets.
Future developments to monitor include government decisions on scrappage policies, how electricity grid decarbonization progresses across regions, and how consumer driving patterns evolve over time. Technologies improving battery production sustainability and EV range could further influence the emissions balance between petrol and electric vehicles going forward.