Beneath the floor of an EV sits a 900-pound battery filled with minerals extracted from around the world. Millions of tons of lithium, cobalt, bauxite and other minerals are mined, processed, shipped and refined — sometimes leaving a trail of human rights and environmental abuses…

EVs already emit less than a third of the emissions per mile than their gasoline counterparts, on average, if you’re plugging into America’s electricity mix. But what if you account for emissions from mining metals, manufacturing, refueling and disposal of EVs?

Noah Horesh, a researcher at Colorado State University who studies life cycle emissions in the transportation sector, has analyzed vehicles’ emissions over their life spans. Horesh estimates fossil fuel vehicles generate roughly twice the emissions of an EV, even accounting for emissions from extracting added minerals and metals.

This difference will only grow as the electricity sector decarbonizes, and battery manufacturing becomes far more efficient. People recharging with clean electricity, or driving smaller vehicles, may already see a bigger difference today.