While decarbonizing the economy is a driving force for decreasing the use of fossil fuels, the steadily decreasing use of coal in America has occurred because of the favorable economics and unanticipated abundance of natural gas through fracking, and will continue regardless of climate policies or environmental regulations, which have played only a small role.
The world is a different matter. Coal is still increasing in developing countries because if you are a poor country with little infrastructure, all you can do is emplace coal.
