Ultimately, mining should be banned from the surface of Earth. Let miners build orbital solar panel infrastructure close to the Sun where power is plentiful. See Bitcoin developer Peter Todd’s 2017-09-10 presentation on the subject (transcript).
Edit: Fixed URL. Edit2; Add transcript link.
Banks will use progressively less energy per capita as bulk data processing becomes more energy efficient, assuming they donʼt transition to using proof-of-work.