lithium. these brilliant blue pools come from wells that tapped underground salt aquifers, each of them nearly 500 football fields long, are rich in lithium. the sun evaporates the brine from the ponds and that leaves lithium behind. >> it's the lightest metal known to man. it's very energy dense. that reactivity in nature makes it hard to come by. >> reporter: does it have an agricultural or impact to the land surrounding? >> we're not using water that would otherwise be used for an agricultural purpose. >> reporter: there is an immense amount of lithium in the western u.s. and multiple ways to mine it. california, for example, could produce enough lithium to meet up to 40% of global demand. on the site of a proposed open pit lithium mine, a warning for the planet. >> lithium is extremely important to tackling the climate crisis. we need to start implementing environmental protections in the production of lithium. >> reporter: and tonight, with u.s. automakers pouring billions into developing electric