Coal has few friends left. Even its best buddy China is conspiring against it, as marked by Beijing's deal last month to buy a rival source of energy, natural gas, from Moscow for 30 years.

China is on a mission to develop natural gas and renewables to clear its skies. In the process, the world's largest consumer of coal will reduce the black stuff's share in its energy mix to below 65% this year from 69% in 2011, partly by tightening the rules for coal-fired power plants, according to a recent government document.

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