麻豆约拍

Most of us may never have heard of Rare Earth Elements but these precious metals such as terbium, lanthanum and neodymium are vital to the electronics we rely on and increasingly to the green technologies we hope to utilise in the future. The automobile industry uses tens of thousands of tons of rare earth elements each year, and advanced military technology depends on these elements, too. Lots of "green" technologies depend on them, including wind turbines, low-energy light bulbs and hybrid car batteries.

97% of these elements are mined in China and as demand has skyrocketed over the last decade from 40,000 tons to 120,000 tons China has started reserving supplies for its own economic expansion. Now, it only exports about 30,000 tons a year - only a quarter of the supply the world needs now and far less than the demands of the green technologies needed for a carbon free future.

The elements themselves are abundant in the Earth's crust. New sources have been found in Greenland and Utah but extraction is difficult and demand seems certain to outstrip supply. Tom Heap searches for solutions to the looming crisis.

Producer: Helen Lennard.