Industries are using pollution permits from governments, which means they buy rights of a certain amount of pollution.
Once the hash rate is determined to pass the threshold of creating environmental damage, companies as Bitmain will be asked to pay for this.
There are laws in every country that demand reduction of pollution and protection of the environment.
So to conclude, everything has a limit. If Bitcoin hash power becomes a problem that causes environmental damage, there are means, like the pollution permits, that won't allow it to happen.
And since you turned it into a POW argument, be certain that this would never happen.
Yes, it should be treated like any other industry that is consuming energy.
So bitcoin mining should not be an isolated case, but rather another rising industry that is revolutionizing the digital technology.
And we are already reaping the benefits of blockchain technology at this stage.
And with that being said, the existing laws in terms of environmental concerns should also be applied to crypto mining and not to be addressed as special case.