I think a blanket carbon tax at least creates a situation where everyone is paying , in some way, for the externalities they're causing. If some industries don

I think a blanket carbon tax at least creates a situation where everyone is paying , in some way, for the externalities they're causing. If some industries don't want to decarbonize because the tax is rounding error to them, then maybe you'd need additional rules or regulations, or maybe we need public investment in some new technology. I can't think of a case where exempting some group from a carbon tax would be good policy. There is a pretty good argument though that a carbon tax would be regressive, and probably should be compensated for in some way so that poor people don't come out worse off, such as by reducing income tax in the lower brackets. I think the hardest sector to decarbonize is going to be the military (with the exception of some small percentage of navy ships that are nuclear powered). I could see plug-in hybrid army vehicles eventually being a thing, though. Being able to run off of either diesel or electricity provides a lot of logistical flexibility. You can save the petroleum for when you really need to move long distances.