A carbon tax was a reasonable idea 20 years ago. Now it would be too little, too late. If the people in favor of a carbon tax had actually been serious and made it happen, then we could have more nuanced discussions now about how to make it work better. As it is, we don't have N more years to argue about what form the carbon tax should take and how to enact it worldwide. Every passing year makes the authoritarian solution more probable and severe.