[vokep]

Bitcoin's energy usage is not correlated with volume of use. The energy usage is correlated with the expected value of newly minted coins. When you think you can get $2 of "mined" currency for every $1 of power, you wont think twice about wasting lots of power on it. When you only expect $1.01 for every $1 spent mining, you'll give up. It self regulates. The current wild case of so much energy being spent on it is due to the value rising quickly over time and expected to rise further. When the overall expectation for the future of bitcoin is that it will plateau or only very slowly climb further, lots of miners will drop out and the energy usage will plummet to an easily justifiable level.