Yes it's wasteful, and yes it's using a fair amount of energy at the moment. But all estimates show it's still a very small fraction of the problem.
It feels like we spend a disproportionate amount of time talking about bitcoins carbon footprint for its size.
I’m glad online currencies exist as a technology but I’m not glad an energy intensive one is currently #1 when at the same time the entire tech is taken over by investors/speculators instead of users.
And if calculations about Bitcoin’s footprint are true it uses up as much energy as Argentina. An entire country. I don’t think that for the use Bitcoin gets in the developed world it justifies energy uses at that level. It’s far from a small little thing to not care about.
Compare for example with MGM's properties in Las Vegas which they claim consume 171 MW. That's not quite as much as Bitcoin, but it's still higher than 65 of the countries listed here: https://en.wikipedia.org/wiki/List_of_countries_by_electrici...
So it's actually pretty easy to surpass the usage of "an entire country". And that to me seems like a much more useless waste than Bitcoin, which has significant uses besides entertainment
If bitcoin was a proof of stake and was the global monetary system I would have to re-think my opinions - at the moment it just seems like a cross between the worst aspects of Wall Street, the cookie clicker game, and the AI Paperclip Maximiser problem.
There's lots of ways to turn energy into money besides bitcoin mining. Gotta make carbon intensive energy not worth it.
That's the reason it comes up a lot in those debates. Sure, cars use more energy emitting more CO2 right now, but the benefit of all the cars worldwide is in an entirely different dimension compared to Bitcoin. Most people intuitively grasp that stuff having a huge benefit for a huge lot of people must be allowed to use up more energy in absolute terms than stuff that has a very minor benefit for a very small group of people.
Which isn't an argument against killing Bitcoin for its contributions to CO2 emissions, mind you, but it seems another similar low-hanging fruit of generating a huge amount of waste to benefit a small number of people economically, while being extraordinarily simple to "just stop doing it". (As opposed to, say, fixing all building insulation in the US, which is a larger problem, and should be done, but is non-trivial to fix.)
With the added benefit that a hundred million people actively hate the existence of junk mail, so I think "we need to ban junk mail because global warming" has legs.