I hope you're trolling.
Power can be generated without an environmental impact. There are companies (and F150s) dumping kgbjillions more CO2 than this person's homelab is. Let people learn something and have some fun.
I get it, it looks cool and damn fun. I dream of this kinds of setup. but brushing off the environmental impact is also wrong.
Now admittedly, he is but a drop in vast ocean when it come to pollution and waste, and there is definitely far worse offender. But keeping our environmental impact in mind should be a necessity in this era.
Individual accountability is important, but self-flagellation or (vicarious) shame because forces bigger than us are causing problems is a waste of energy (ha!).
It's similar to when there's hypocrisy charges levied against "champagne socialists." Nice virtue signalling for worker's rights for someone with a 6 figure income... meanwhile that 6 figure salary accounts for 0.01% the net worth of a billionaire.
Go for the high stakes first, then we can worry about homelabs pulling more power than they should.