BBC: Locals in Datong call it the coal capital of China - and it is not hard to see why. Outside the city you can see enormous mining towers and buildings scarring the landscape.
At one coal pit the bulldozers are hard at work. They push huge mounds of coal close to the waiting trucks. The air is filthy, blackened by the coal dust.
This is a dirty, grimy business but in China it is crucial work. Coal has fuelled the country's economic boom, with consumption tripling in little over a decade.
Currently,...