Mark Gimein, writing for Bloomberg News, commented that bitcoin mining uses quite a bit of power. Enough that he calls it a “real-world environmental disaster”:

About 982 megawatt hours a day, to be exact. That’s enough to power roughly 31,000 U.S. homes, or about half a Large Hadron Collider.

[…]

Real-world mining of precious metals for currency was a resource-hungry and value-destroying process. Bitcoin mining is too.

Others aren’t quite convinced that virtual mining causes the same level of environmental destruction that the real thing does.