I would like to enforce a coal ban, but nobody gave me an army with which to do so. Not that I could've enforced it for all those years even if I had an army,

I would like to enforce a coal ban, but nobody gave me an army with which to do so. Not that I could've enforced it for all those years even if I had an army, as coal was dominant for so long for the same reason it is now being rapidly displaced: cost.