Britain and other Western countries risk running out of supplies of certain highly sought-after rare metals that are vital to a host of green technologies, amid growing evidence that China, which has a monopoly on global production, is set to choke off exports of valuable compounds. Failure to secure alternative long-term sources of rare earth elements (REEs) would affect the manufacturing and development of low-carbon technology, which relies on the unique properties of the 17 metals to mass-produce eco-friendly innovations such as wind turbines and low-energy lightbulbs.