I would not say best option, rationing is the best option. Taxes might reduce demand but that is not certain, it will not reduce the demands of the rich, only the poor will be forced to cut back. I say ration carbon emissions. Give the rich and the poor the same ration. Nobody gets to pollute more than anyone else. With rationing, you can control emissions, with taxes or fees you can at best try to manipulate a reduction. Rationing would be a sure thing.

TEK

TEK