On the road before the clean running of an EV makes up for the emissions created during its manufacture, according to scientists at Duke University in the US. The cars get off to a messy start because of emissions caused by mining lithium and building the battery. But across an EV’s lifespan, the scientists calculate, its “footprint”—in terms of damage to the climate and air quality—is two to three times smaller than that of a car running on fossil fuels.