> Visa, MasterCard, AmEX, &c along with each individual bank, not to mention the intermediaries and gateways all of them use also consume a tremendous amount of power.
But is it more or less than the equivalent amount of power it would take for Bitcoin (or something like it) to scale to Visa, MC, AMEX, etc. global levels?
That's what I don't have good numbers on, I was just pointing out that talking about bitcoins using a lot of energy isn't a good argument unless you're comparing it against the current system, which also uses a substantial amount of power. The big question is what you're asking: How do they compare?
I think that depends on how much mining hashing power scales with regard to transaction rate. From a technical point of view, there's no reason that the hash rate has to increase to process more transactions. But from an economic and game theoretical point of view, increasing transaction rate makes the network more valuable, which makes attack rewards more valuable, which necessitates a higher hash rate. I'm not sure anyone has sussed out what the relationship is between transaction rate and minimum necessary hash rate.
But is it more or less than the equivalent amount of power it would take for Bitcoin (or something like it) to scale to Visa, MC, AMEX, etc. global levels?