Often referred to as "digital gold," bitcoin has taken a lot of criticism over the energy costs of "mining" it. But the computation heavy process that bitcoin uses appears to be far less resource intensive than the energy costs to produce the yellow metal. A detailed analysis at LongHash attempted to approximate the total energy expended on bitcoin mining and concluded it was about $4.3B worth. The analysis then explores a leading gold miner's total cost of operations, a stunning $794 per ounce of gold -- the metal currently sells for $1,200/oz.. The source for the info is the annual report of the firm Barrick, which spends so much on diesel to mine gold that it's possible to extrapolate a whopping $6.0B is spent just on fuel for gold mining.
That leads to the conclusion that gold mining uses around 0.27% of worldwide oil production vs. bitcoin's 0.07% use of global electricity. While that may be apples to bananas, it's worth noting that gold ore requires significant energy to process and smelt into gold ingots, so the $6.0B figure likely understates the true energy cost of gold mining significantly. (Source: LongHash)