Although driving electric vehicles will generally emit less CO2 than using petrol ones, electric vehicles are tooled with heavy batteries that are loaded with rare minerals, and producing them is far more energy intensive than for other vehicles.

Researchers at the University of Michigan were interested in calculating the whole life cycle of the vehicles, including both the manufacturing process and the use on the road.

The research concluded the CO2 generated by producing an electric vehicle was largely balanced out during the rest of its lifetime.

“The study showed for the first time that BEVs (battery electric vehicles) have lower emissions over their lifetime than any other vehicle type in every county in the contiguous US,” said a statement accompanying the research, published in the journal Environmental Science & Technology.

The authors used a statistical model to estimate the emissions per mile driven in the US in 35 combinations of vehicle and power generation.

On average, an electric vehicle with a range of 300 miles (480 kilometres) will cause 30% less emissions over its life cycle than a plug-in hybrid car, around 60% less than a non-plug-in hybrid and about 70% less than a car with a petrol combustion engine.

The US government under president Donald Trump has moved away from policies offering incentives and tax breaks to encourage uptake of electric vehicles and renewable energy.

But Greg Keoleian, senior author of the new study, said the industry was committed to the technology.

“EVs are becoming the dominant powertrain in other parts of the world, and manufacturers recognise that is the future for the US,” he said.