Long-term shortage of coal

Nature 
Although the world's total coal reserves considered together are sufficient for many centuries beyond the expected date of depletion of petroleum, some major producing countries are experiencing a shortage of certain coals, including those used for high-grade coke which is needed for the iron and steel industry and for fuel.
Counter-claim 
From 1980 to 1990 the price of coal decreased by almost 50 percent whilst reserves increased.
Value(s) 
Type 
(E) Emanations of other problems