The War Below: AS HEARD ON BBC RADIO 4 'TODAY'

The world is moving towards replacing fossil fuels with renewable energy. But building electric vehicles, solar panels, and millions of other devices requires digging more mines. Critical minerals are vital to many sustainable technologies, and the competition for them is intensifying.

Nations which aspire to energy independence are ever more intertwined: a hedge fund manager's attempt to revive rare earths mining in California needs Chinese expertise, and international reliance on Africa's mining sector persists despite concern over child labour. Meanwhile, ecological dilemmas abound: a proposed lithium mine in Nevada would help global car manufacturers slash their dependence on fossil fuels, but developing that mine could cause the extinction of a flower found nowhere else on the planet.

As investors attempt to predict how the geopolitics of resource extraction will unfold, this is a story of the industry giants, researchers, and policymakers at the forefront of the new energy wars.