The total energy consumed by the miners on the bitcoin network is probably less than two large semi-trucks (~350 kWatt) ... is it really such a huge burden on the environment considering the millions of trucks on the roads carting useless crap around for wasteful govt. projects?
Go pick on someone who's really fucking things up.
It's not just energy that's being wasted in theory, though; it's also computing power unnecessary to the core task of Bitcoin except that it has a predictable difficulty.
It would be nice if the mining process could incidentally cause some external benefit. If we were deciding between two scarce physical stores of value (say, gold and something else), and gold requires the mining process it does today whereas the alternative requires equivalent expense and involves equivalent scarcity but happens to reduce global warming or contribute to medical research, there would be little reason to choose the former. (The only reasons would involve the purity of the object as a store of value without any incidental worth, but there's little reason in an efficient economy to believe that that matters in the long run.)