One objection — the claim that carbon taxes are better than cap and trade — is, in my view, just wrong. In principle, emission taxes and tradable emission permits are equally effective at limiting pollution. In practice, cap and trade has some major advantages, especially for achieving effective international cooperation.
Not to put too fine a point on it, think about how hard it would be to verify whether China was really implementing a promise to tax carbon emissions, as opposed to letting factory owners with the right connections off the hook. By contrast, it would be fairly easy to determine whether China was holding its total emissions below agreed-upon levels.
The more serious objection to Waxman-Markey is that it sets up a system under which many polluters wouldn’t have to pay for the right to emit greenhouse gases — they’d get their permits free. In particular, in the first years of the program’s operation more than a third of the allocation of emission permits would be handed over at no charge to the power industry.
Now, these handouts wouldn’t undermine the policy’s effectiveness. Even when polluters get free permits, they still have an incentive to reduce their emissions, so that they can sell their excess permits to someone else. That’s not just theory: allowances for sulfur dioxide emissions are allocated to electric utilities free of charge, yet the cap-and-trade system for SO2 has been highly successful at controlling acid rain.