There's some good data here - that being said, even if the carbon footprint were literally zero, I couldn't personally support cryptocurrency. Fundamentally it's the antithesis to democracy. Say whatever you will about all forms of government, but ultimately no matter the form, there's some level of accountability. Some governments use elections to facilitate this, others use the threat of rulers being killed. One wa…
No one is forced to use crypto. No one is forced to mine it. No one is forced to use it at all. Is this not democratic? The users choose whether they want to use it, miners choose whether to mine it, and the "lack of accountability" you suggest, I just don't agree with at all.
Crypto removes the need for government fiat. There is no need for a central authority any more over money supply. If you don't like it, fork it, or create a new crypto, and market it. See if it catches on. The democracy of the people will decide whether to use it or not.
Some cryptos also have voting / governance rights, so the users can democratically vote on protocols, directly. In comparison, if I want a law to change at the federal level in the US, first of all there has to be a bill created in support of it (which I have almost zero control over), and then I can call my senator and ask that they support that bill. At that point they can choose to listen or not. I assume they will just do whatever is in their interest to stay in power and support their friends in government that supported them before, not to mention the lobbyists. Even my vote for president in the US in the end is decided by the electoral college, not by the popular vote. How is all of that democratic?
I understand the energy concerns with crypto, but since you are figuring in a zero carbon footprint, I disagree and think you completely miss the benefits that crypto offers over existing systems.
In the end, time will tell and I think there's almost no way that blockchain and crypto won't play a major part in future economies and governance.