EVs drive real-world cut in air pollution, study proves

A new study has confirmed a clear link between EV adoption and a rapid reduction in harmful gases that can cause heart disease, strokes and bronchitis.

The benefits of EVs for air quality have long been assumed, but the new analysis uses quantifiable data to show that rising adoption levels of battery powered vehicles have led to falling levels of nitrous dioixide (NO2).

The research, by scientists at California’s Keck School of Medicine of USC, examined the uptake of EVs and plug-in hybrids and compared it with data on NO2 levels in 1,692 California neighbourhoods across four years from 2019 to 2023.

It found that for every 200 plug-in vehicles added to a neighbourhood, NO2 levels dropped by 1.1%. While the data focused on one US state, it is a positive indication of the wider global benefits of EVs.

The report, which was published in The Lancet Planetary Health,  is among the first to confirm the public health benefits of plug-in vehicles.

Its authors obtained their findings by used high-resolution statewide satellite data. They were able to analyse NO2 levels in the atmosphere by measuring how the gas absorbs and reflects sunlight. They then compared the changing levels of NO2 with data from the state’s Department of Motor Vehicles to track EV and PHEV adoption. As well as finding a clear link between EVs/PHEVs and lower NO2 levels, the found a corresponding increase in NO2 levels where there was a rise in petrol-powered vehicles.

The team had previously used ground-level monitors which suggested similar findings, but the satellite data provided more definitive data backing up the theory.

The report’s lead author, Sandrah Eckel, Ph.D., associate professor of population and public health sciences at the Keck School of Medicine, commented: “We’re not even fully there in terms of electrifying, but our research shows that California’s transition to electric vehicles is already making measurable differences in the air we breathe.

“These findings show that cleaner air isn’t just a theory—it’s already happening in communities across California.”

Along with the now-proven link to lower NO2 levels, EVs are also responsible for far lower carbon dioxide emissions, even taking into charging. It is estimated that an average family EV is responsible for around 50g of CO2 per kilometre driven, including the electricity they generate. Meanwhile, a diesel produces 170g. Over the course of a year, one EV will save an average of over 1.5 million grams of CO2 – the equivalent of four return flights from London to Barcelona.

In addition to producing 0 grams of CO2 when driven, the lifetime CO2 footprint of an EV is lower than that of a petrol or diesel car, despite the higher initial CO2 cost associated with their manufacture.

And the time it takes for an EV to reach break-even with an ICE model is falling all the time. Initially, EVs were expected to offset the additional carbon used to build them within seven years of driving. Yet as technology and production techniques have advanced in recent years, this  has been slashed.

Last year, when BMW launched its new X3, the Munich-based carmaker announced that the latest version of its mid-sized premium SUV will have a smaller environmental footprint than its petrol-powered cousin within less than two years of driving, the equivalent of 13,359 miles.

If the iX3 is charged solely with renewable energy, then the CO2 break-even point is slashed to 10,874 miles.

This has been achieved because BMW decarbonised the entire production chain of the iX3 by 35% by using renewable energy, and using “secondary” or recycled materials – the latter of which includes seat fabrics made from recycled PET bottles, and metal components such as wheels and wheel carriers made from 70% to 80% recycled aluminium.

Volvo has followed a similar path with the ES90 saloon. Despite being significantly larger than its smaller electric stablemates, the EX40 and EC40, it has a smaller carbon footprint and can emit as little as 26 tonnes of CO2 over a lifespan of 124,000 miles.

Like BMW, Volvo has reached this point by building the ES90 from a blend of 29% recycled aluminium and 18% recycled steel. Inside, the S90’s cabin uses 16% recycled polymers throughout, including FSC-certified wood.

The possibilities for further emissions reductions extend beyond the use of recycled plastics. Last year, when it launched the Emblème, Renault found that its “rolling laboratory” would emit just five tonnes of C02 over the course of its life – the equivalent of 200,000 kilometres – by using a Euro-centric supply chain of nearby suppliers and exploring the use of new construction materials such as pineapple fibres.

While purely a concept car for now, Renault insists that were the Emblème ever to make it to production, no rare earth elements would be used in its 40kWh battery, either.