As a thought experiment, if you took out the mining rewards tomorrow and had only transaction costs, the energy put into each block would be much lower and be a

As a thought experiment, if you took out the mining rewards tomorrow and had only transaction costs, the energy put into each block would be much lower and be a function of the value actually provided in each transaction. Plus the value of existing Bitcoin would go up because of even more scarcity. I'm not saying Bitcoin should do that, but as proof-by-construction that a more green coin with the same properties could exist.