Bitcoin is good for the environment. The things that affects the environment is not the bitcoin itself but the tecnology that we used to generate bitcoin. Like mining and other power source that produced radiation.
Bitcoin does not affect the environment, its not either good or bad for the environment, The system used where they required a lot power energy supply for miners, just maybe can have some effects on the environment but not until today no one knows about this except the report of power energy consumption as to how much power we are using on the certain period of time.