I read about the wars of miners building bigger and bigger setups, grouping together for stable income, buying cheap electricity wherever possible... and it's not too hard to imagine a future where a sizeable portion of energy expenditure and carbon burning is going to very strong computers doing very complicated stuff for magic make-believe money.
It reminds me of Easter Island. The prevailing theory goes like this. The islanders made big stone heads (Moai) to honor some famous chiefs. Everyone was impressed. Then some rich bigwigs decide to make Moais for themselves. Then every Joe Shmoe with some money decided THEY wanted a Moai too. The island went nuts for Moais and they ended up cutting down all the trees on the island, destroying the ecosystem and the entire civilization collapsed and disappeared.
But... Moaicoins only go up!