Chinese chemists consider the effect of coal on their atmosphere.

[NNadir]

"Coal is the main energy resource and form of energy
consumed in China. It is estimated that the mined coal
reserve in China is 114.5 billion tons and presently
constitutes 70% of the primary energy sources. Meanwhile,
it is also the main pollution contributor: 90%
of SO2, 67% of NOx, 82% of acid rain, and 60% of
particulates in the atmosphere originate from the direct
combustion of coal in China...

...Sulfur is a major factor in regard to inhibiting the
extensive utilization of coal. Therefore, the desulfurization
of coal is very necessary to improve coal quality and
protect the environment. Although many methods have
been developed for coal desulfurization, an effective and
economic process remains to be found..."

From the upcoming issue of Energy and Fuels...

http://pubs.acs.org/cgi-bin/abstract.cgi/enfuem/asap/abs/ef049773p.html