Cryptocurrencies and Global Warming

Cryptocurrencies are quite the rage. I understand that they require a tremendous amount of energy. If there’s any reasonable hope of slowing global warming, carbon emissions should be taxed and carbon neutral initiatives should be subsidized, in each case in proportion to their cost or benefit to humanity. If such a policy were followed, I suspect that crypto currencies would fade away. Since such a policy is not likely to be followed, I suspect that they are here to stay.