Fiat currencies proof-of-work is taxation, inflation and interest rate control. That accounts for 1/2 of your productivity, just so that governments can have a

Fiat currencies proof-of-work is taxation, inflation and interest rate control. That accounts for 1/2 of your productivity, just so that governments can have a monopoly on their currencies. Not to say that managing fiat money is tremendously wasteful. Credit cards alone take 3% of every transaction on fees that barely make sense. Banks charge ridiculous taxes on pretty much everything they do, and don't even guarantee your money can be withdrawn. Gold and silver on a per unit-of-value basis require more energy to mine than Bitcoin. When you compound all of that, you'll realize that Bitcoin energy expenditures are overall not so much of a big deal. But if they are a big deal for you, at least be consistent and go after gold and silver mining, to start with, and do fight against governments' monopolies on currencies, as those are a lot less "green" and more widespread than Bitcoin. Additionally, you can come up with new blockchain technologies that don't require PoW, and/or support the existing ones that don't require PoW by parking your money on them. You can also short Bitcoin in a futures market in order to protest against it.