[compton]

How do you think coins are made? And distributed? Of course at the moment, both systems exist so it appears that blockchain is additional and therefore unnecessary. Isn't that often how new technology first appears though?

As another example, there have been similar articles about the amount of energy used by internet datacentres. While a lot of energy is certainly used to keep the internet running, such figures are only really meaningful when compared against the existing systems they can replace. What is the environmental impact of building libraries, stocking them with books, heating and lighting them, and the physical journeys that their users have to make to get there?

[not_kurt_godel]

I'm pretty sure electricity use of the existing currency system does not alone potentially account for 2 degrees C of global warming. Since you know, making a physical coin doesn't require deliberately burning untold numbers of CPU cycles for each transaction once it's made (nor does any corresponding digital record-keeping of it either).