> you don't have to pay for the negative externalities of carbon.
We aren't yet seeing much indication that there will be a global tax/fee on the externalities of carbon. That means even if local policies are implemented for certain cases (eg. no gas cars in the city, no coal power in one state), there will always be somewhere on earth willing to burn dirty coal to make helicopter fuel for export.
Right now, the market is artificially big, because you don't have to pay for the negative externalities of carbon.