Comment by kspacewalk2

The more you tax something, the less of it you get. Imposing a non-zero cost on carbon will always be strictly better at reducing carbon emissions than imposing a zero cost on it. How effective it is depends on how big a tax it is, of course, but usually governments addicted to a tax tend to increase said tax, which in this case makes it better, since it will disincentivize emissions even more.