The growth in supply would not slow - in Bitcoin every two weeks you have a rebalancing of difficulty, so if miners have less hashing power the difficulty of producing each block gets lowered to keep the supply stable.
Sure, but energy usage still goes down. Revenue from block rewards is limited. Costs can’t exceed revenue or unprofitable miners will drop out. More money spent on one expense (the carbon tax) would mean less can be spent on the electricity itself.
Or more likely they’re outcompeted by anyone who doesn’t have to pay the tax, such as miners using green energy or in a jurisdiction without the tax.
Or more likely they’re outcompeted by anyone who doesn’t have to pay the tax, such as miners using green energy or in a jurisdiction without the tax.