Completely irrelevant. Because other uses of energy (that me and lots of other people consider wasted or even harmful) are orders of magnitude larger and thus harmful than Bitcoin's.
Either you accept that not every person on the planet agrees upon which uses of energy are useful to them individually. Or you're basically saying "my opinion on which energy uses are legit and which aren't is the only one that matters", at which point we can stop discussing altogether because I don't really care about "discussing" with people who have this standpoint.