Bitcoin is an almost perfect exploitation of humanities fatal flaws (greed, unwillingness to acknowledge externalities - i.e. selfishness). It's that old SF-trope that the cause of many of humanity's biggest problems is humans.
Thought question here. What if we hyped up bitcoin to 10X its current value? Wouldn't that mean that per real-world transaction / per unit dollar value it would use 1/10th of its current amount of energy? For example something that would normally cost 0.1 BTC would now cost 0.01 BTC.
10x price increase equals 10x mining expenditure, mostly on energy.