In industrial cities, thousands of cables and pipes are left abandoned under our feet. It's a valuable source of metal that could be given a second chance. Join the team in downtown Sweden as we explore whether our cities are the mines of the future.
This week we're in Sweden, on a hunt for urban treasure. Beneath many of its downtown streets lies a bounty of abandoned metal trapped in forgotten cables and pipes.
We meet the Swedish prospectors who believe cities will be the mines of the future. Researchers from Linköping University have shown the amount of copper under the pavements is equal to that found in the country's traditional mines.
Today it's too expensive to dig up this network of underground infrastructure, which includes copper as well as iron and aluminium, but efforts are underway to change the economics of urban mining.
Austrian-based company Kabel-X has developed technology that can extract up to 400 metres of copper in one piece. As Sweden's telecommunications provider makes the switch to fibre optic cables, it could be the perfect opportunity to tap into this reservoir of metal and give it a second life.