Cobalt is one of the 118 chemical elements, and it's a vital ingredient in making batteries for everything from your mobile phone to electric cars. Land mining for cobalt and other metals can be environmentally and socially damaging, but proposals for the deep sea mining of these metals in the Clarion-Clipperton Fracture Zone - the CCZ - an area about as big as Europe four thousand metres below sea level in the Pacific, is also controversial. Eva Higginbotham... Like this podcast? Please help us by supporting the Naked Scientists