I don't feel like that crypto currencies are harming the environment more than any traditional FIAT currency. We need to consider so many factors when comparing FIAT to crypt currency. Printing money and minting coins requires a lot of resources and energy, the same goes for running a lot of different banking offices across the country. Delivering money to the ATMs also consumes a lot of fuel. So if we consider all these factors than traditional money requires much more energy than cryptos. I don't like that Elon Musks buys a lot of Bitcoins, hypes them on Twitter just to make a good profit and now gets out of the market.