To be clear, the source would still be the consumer. Hydrocarbons can be used for non-CO2 emitting purposes such as chemical feedstock for pharmaceuticals, solvents, etc. We should only be levying a tax upon uses that emit CO2 into the atmosphere, i.e. burning them in your ICE vehicle. It’s not the fracking company that’s emitting the CO2 (unless they’re gas flaring or similarly emitting carbon during extraction but this is a rounding error on total emissions).