The resources race is on. Powering our digital lives and green technologies are some of the Earth’s most precious metals ― but they are running out. And what will happen when they do? The green-tech revolution will reduce our reliance on nuclear power, coal, and oil, but by breaking free of fossil fuels, we are setting ourselves up for a new dependence ― on rare metals like cobalt, gold, and palladium. These are essential to electric vehicles, wind turbines, and solar panels, as well as our smartphones, computers, tablets, and other technologies. But we know very little about how rare metals are mined and traded, or their environmental, economic, and geopolitical costs ― until now.