The thing is, Bitcoin doesn't have to use a ridiculous amount of energy. You could theoretically run the entire network from a single miner running on a 10 yea

The thing is, Bitcoin doesn't have to use a ridiculous amount of energy. You could theoretically run the entire network from a single miner running on a 10 year old Android. The problem is that the proof-of-work system creates an arms race and everyone starts building massive mining farms in order to get a bigger piece of the block reward pie. Some proponents will claim it's necessary for decentralization, and to a point, it's true, but we definitely don't need the amount of mining power in use today.