One troubling aspect of the bitcoin proof-of-work is its tendency to eat the world. Miners will tend to expand their operations until the electricity cost app

One troubling aspect of the bitcoin proof-of-work is its tendency to eat the world. Miners will tend to expand their operations until the electricity cost approaches the block reward. So if we plug in some numbers[1] we can estimate that bitcoin may soon consume a significant fraction of all electricity production. And it gets even worse as the price rises. [1] http://www.wolframalpha.com/input/?i=(2500$%2Fbitcoin+*+12.5+bitcoin+%2F+600+seconds)+%2F+0.05+$%2Fkwh+as+a+percentage+of+global+power+consumption http://www.wolframalpha.com/input/?i=(2500$%2Fbitcoin+*+12.5...