As long as we are making large unilateral changes:
We should have a re-distributive carbon tax.
We should have a re-distributive carbon tax.
This prisoner's dilemma comes up so much in global politics, it should have it's own name.
The issue of who gets to produce carbon, how much and for how long is really huge and is not dominated by any singular issue.
You can't really ban proof-of-work practically anyway, but you can make quite easily make dirty electricity more expensive than clean electricity.