Earlier quoted context omitted.
Isn't the environmental concern temporary? Once all the bitcoin has been mined, the computational requirements for maintenance of the network will certainly decrease significantly. One could argue that Bitcoin should reach the limit sooner, so that mining difficulty would not increase so much, but the mining incentive is mainly a bootstrapping strategy for a currency. Now that everyone is familiar with how the ecosys…
The energy cost isn't exactly in creating bitcoins. The energy cost is in securing the network against people doing 51%-attacks, and bitcoins are set to be minted out of thin air and transaction fees are paid out in order to incentivize people to protect the network. Mining will still be necessary after all bitcoins are minted, or else anyone could 51%-attack the network and double-spend bitcoins.
If you think the amount will be roughly equal, then you are predicting that transactions that end up in blocks will need to voluntarily contribute an amount equivalent to the block reward in order for the system to continue functioning. This seems unlikely to me.