Has "The idea of taxing cryptocurrencies specifically for carbon emissions" been proposed? I don't see it mentioned in the article discussed here. I wish the article had proposed that idea, it'd be more complete if it had -- it doesn't propose anything as far as I can tell.

I agree that a general carbon tax would be better, and as a bonus, there's various progress toward just that around the world. But I'd find the argument you're making more compelling as a rebut to focus on cryptocurrency carbon footprint if the players in the cyrptocurrency industry were forcefully lobbying for general carbon taxes. Are there any examples of that?