If you care so much about having less harm done to the ecosphere then why are you currently debating about "tiny slice of greenhouse gases" (Bitcoin) that other people arguably find very useful, instead of focusing on the "bigger portion of the emissions pie" (perpetual consumption of unnecessary new stuff in the post-modern consumerist society)?
I have a hard time believing you care more about the environment than about trying to blow the supposed evilness of Bitcoin out of proportion.
> Bitcoin is crazy wasteful compared with other financial tools which can do the same thing.
Good, which are these?
The one financial tool that somewhat comes close is gold, and because the latter implies orders of magnitude slower transfers than Bitcoin and because it's harder to secure and comes with a few more downsides on top it's still far from "same thing".