The key question raised in the parent comment, which your own riposte artfully dodges, is once again - who stands to benefit from this N% increase in global energy usage?
As far as a justification goes, I think that if BTC reaches 2 trillion, it will have gone mainstream. Meaning either existing transactions should become easier, or people find it a good store of value.
This isn't just theoretical. The marijuana industry faces immense hurdles dealing with the traditional financial system, because marijuana is technically still illegal at the federal level. This makes it a nightmare to do any of the normal banking operations we take for granted. Bitcoin sidesteps this problem while also letting you be legal: As long as you declare your taxes properly, Uncle Sam probably won't come knocking.
That's just one example of an industry that benefits. There are many more.