This week's ruling applies to materials like bauxite, coke, magnesium, manganese and zinc, but, most notably, does not apply to rare earths -- a group of 17 elements critical to the production of tablets, smartphones and myriad other gadgets.

ENGADGET: WTO ruling revives debate over China's rare earths trade

Peak neodymium is the latest threat to green energy, while doubt emerges over the security of many other element groups including the rare earths, the platinum group metals, and elements such as antimony, beryllium, gallium, germanium, graphite, indium, magnesium, niobium, tantalum and tungsten.

FORBES: Endangered Elements Pose Threat To Green Energy