Bitcoin and cryptocurrency in its current form is environmental lunacy. I don't know what problem digital currency solves when the planet can no longer sustain human life due to climate change.
https://www.theguardian.com/sustainable-business/2017/jul/10...
I struggle to find hand wringing about bitcoin's energy consumption as anything but naive or sour grapes.
Society is never going to voluntarily reverse total energy consumption. Either price bitcoin mining out of the market, or focus on voting with your wallet and regulating carbon emissions at the energy production level. Arguing about how people should spend their money on energy is a waste of political energy.
Millions of people believe that bitcoin is worth the energy costs. "Too much" energy usage is entirely subjective.