Bitcoin mining around the world now produces as much CO2 as Ireland. 80% of the money generated by the Bitcoin mining is used to cover the electricity costs generated by their mining stations.
Currently, according to a survey by journalist Alex Hern from the Guardian, the power consumption of the Bitcoin network alone would reach 42 TWh, which is equivalent to the emission of 20 megatons of CO2 per year. This is what Ireland produces. Furthermore, the more time passes and more Bitcoin becomes difficult to mine, it requires more computing power and therefore greater power consumption.