The tonnage of mined coal hit a peak in 2008, and the energy value of mined US coal hit its all-time peak a decade earlier, in 1998, at 26.2 quadrillion BTU.
The tonnage of mined coal hit a peak in 2008. The energy value of mined US coal hit its all-time peak a decade earlier at 26.2 quadrillion BTU. This was in 1998.