It has becoming a time that some mining companies are using waste product of crude oil refineries for generating energy, what would have been burned as a flare before. Bitcoin is also helping to make the waste products to be useful.
Some people are still talking about global warming, it is real and the world is becoming hotter, but not because of bitcoin mining or bitcoin generally but because of other human activities.
If there is no bitcoin, there will still be global warming.
Exactly it is all just a FUD by some bitcoin haters that is actually causing global warming. But come to think of it there are many industries out there that emits heats.
OP here are links that supports why bitcoin is energy efficient.
1. NotATether article on
bitcoin been energy efficient2. Bitcoin cleanup website to stop Greenpeace FUD towards
bitcoin