"China has long dominated the world's supply of heavy rare earths, minerals needed to build electric vehicles and wind turbines. Demand for these products is skyrocketing as we rush to meet climate goals, but there is a problem at the root of the supply chain. The processes used to extract heavy rare earths are highly polluting, ravaging landscapes and poisoning waterways. As concerns over the environmental toll of extraction have grown in China over the past decade, more and more domestic mines have been shut down. Yet global demand is growing rapidly, and China remains the world's largest processor. But with many of its own mines now closed, where is China's supply of these minerals coming from? A six-month investigation by Global Witness followed the outsourcing of this highly toxic industry across the Chinese border into Myanmar. There, heavy rare earth mining has exploded so quickly that within just a few years a mountainous corner of Myanmar, known as Kachin Special Region 1, has become the world's largest source of supply. This region is a semi-autonomous territory run by militias that are affiliated to Myanmar's brutal military regime. The mining is illegal under Myanmar's laws, and hardly exists on paper. Yet the damage that global demand for products manufactured by international companies is fuelling in this remote, lawless part of the world is all too real for the communities who are now risking their lives to defend their land. LEACHING MYANMAR'S MOUNTAINS For Zau*, a local worker, the mining boom is a rare chance to make money. He is paid 3,800 yuan ($600) in cash every month, around twice the average salary in Myanmar. He works in the shadows, at a mine near the Chinese border, for a company that has no permits. On paper, Sin Kyaing Company is owned by a local militia leader called Lagwi Bawm Lang. But like other Burmese companies in the rare earth mining industry, it is really a front for illegal investment by Chinese businesspeople. Zau's job is to remove vegetation and drill holes into the mountains. Then ammonium sulphate solution is injected into the holes, effectively liquefying the earth. Once the chemicals have percolated through the mountainside, the solution is drained into bright blue collection pools, where minerals are precipitated out in a process called in-situ leaching. After this mountain has been leached, Zau and his colleagues will abandon the contaminated site, moving to the next place and starting all over again. “In my opinion, the mountains will definitely collapse one day,” Zau told Global Witness, alluding to the risk of landslides. Despite being paid well, he is worried about the harm the chemicals are causing to the water supply, and therefore to the health of local people. “People from the surrounding villages are facing difficulties getting drinking water,” he said. “Even healthy people like us feel dizzy if we inhale these odours for a long time.” The mountains beneath Zau's feet are rich in ores of dysprosium and terbium, the two most valuable of the heavy rare earth metals. Described by an industry expert as “basically irreplaceable”, we rely on them for a whole range of clean energy and smart tech products – from the smartphone you may be using to read this story, to your energy-conserving home electronics. But their most important use, representing 90% of their value, is in permanent magnets, which are needed to make motors and generators for electric vehicles and wind turbines. The stakes are high: it would be almost impossible to build a low-carbon future without these products, and many of them currently do not work well without heavy rare earths..."