Rare earths are essential to green technologies, but China supplies 98% of them. Some have risen in price 200-fold – by 20 000% – in a year. Is China holding the world to ransom? A World Trade Organisation case is brewing. Rare earths are not rare, say Mark Tyrer and John P. Sykes; but it does need statistics to understand the likely outcome of the WTO case – and why the industry is important.