Cryptocurrencies appear to be digital and therefore environmentally friendly. But in effect, they are a carbon nightmare.
Apparently, each Bitcoin transaction generates as much as 400kg of carbon dioxide. This is equivalent to over 800,000 visa transactions. Why does it emit so much carbon dioxide? Simply because of the computations required of the servers required to verify the uniqueness of the token.
There must be a way to address this so that it does not negate all the global efforts to be more environmentally friendly. Check out this article that explains the details.