Bitcoin is only as ecologically harmful as the source of the electricity used to run the miners, and it's no more harmful than any other use of electricity. If the world switches over to solar and wind as baseload power, problem solved. If the world doesn't switch away from using coal, that's not Bitcoin's fault. It's not a problem Bitcoin can solve.
That's a tautological statement. My 50,000 watt bulb that I shine inside a closed box is also "no more harmful than any other use of electricity," but the question is whether I should be using that electricity in the first place.
You can argue whether the "wealth" generated is worth carbon dioxide released into the atmosphere, but you can't deny that more carbon dioxide has been released because of BitCoin.
Back to my lightbulb in a box: "If the world switches over to solar and wind my 50,000 watt useless bulb's problem is solved. If the world doesn't switch away from using coal, that's not my fault. It's not a problem I can solve."
Not the same kind of value. You can mine a billion coins tomorrow and society will still be stuck with the same junk it has today. You could mine a billion tons of cobalt tomorrow and give us all nearly free batteries in perpetuity.
Printing a $25 or a $100 note must be an involved process, though.
I don't see any way around this limitation. Eventually the difficulties will be so high, and finding blocks gets harder and harder, keeping it on a traditional power source would not be prudent.
Sure, if you take it out of the context of the rest of my comment. But OP asked if Bitcoin would stop being an ecological disaster, and my point is was that Bitcoin's ecological costs are primarily about the source of the electricity, not the amount of electricity.
Bitcoin mining uses about 170 MWe, continuously. That's really not very much in the grand picture of things. A few medium-sized fields of solar panels isn't an "ecological disaster".
And how does that claim hold up when you compare current level cryptocurrency adoption to the scale of money worldwide?
How does energy usage scale with the number of users in general? Linearly?
You're confusing Bitcoin miners and Bitcoin nodes.
Bitcoin nodes verify transactions. You can run a Bitcoin node off your home PC. It doesn't use much energy.
Bitcoin miners are what use all the energy, and their energy use is driven by the size of the mining rewards not the number of users.
You basically answered a different question, because this doesn't tell me how it scales
I'm sure I'm off a little bit in my understanding, but I thought part of the idea whole blockchain thing was being a decentralised ledger. How does that scale if everyone is on it? Is the energy use better or worse than a centralised bank, by how much, and is it significant?
Instead it tends to gravitate fairly quickly to places that currently have an surplus of energy and therefore extremely cheap power generation.
In the US that is Washington state, near Wenatchee, where the power is the cheapest in the nation: http://www.electricitylocal.com/states/washington/wenatchee/
The reason for that price is that it is all hydro, so no co2 produced. (though depending on how fungible you view power it could be argued otherwise) http://www.wenatcheeworld.com/news/2011/jun/01/cheapest-elec...
But ya, though I agree the amount of power that goes into mining and keeping the blockchain safe is absurd, the crazy competition and economies there have driven most of that to green sources. So yay I guess?
You've misunderstood something about Bitcoin if you think this is true. Bitcoin miners use resources based on the logic of competing with each other for the value of the mining reward, not based on the number of transactions they process. If Bitcoin solved all its scaling problems so that everyone in the world could use Bitcoin, but mining rewards remained constant, the resources the miners expend to collect the reward wouldn't be any different from today.
That's not quite true though is it? They could certainly (for instance) block transactions and generally hold the whole thing to ransom.
You're right, it doesn't have the financial incentive that you could (for instance) steal coin, but you could potentially block all transactions that don't have a considerable fee, for you, or just break stuff. Motives to do that will become more pressing the higher value the network is to nation states.
As more miners join, more power is used. But at the same time, miners could be removed, and hash capacity lowered, and the number of transactions per hour would be still the same.
So: energy used: number of miners. Transaction capacity: block size.
Both things are orthogonal. One number is independent of the other.
Right now the protocol is being updated to increase transactions per hour, and this has little to do with the number of miners.
To resume: if the world's economies ran on Bitcoin, because of some big transaction capacity increase, then the energy used would be about the same, because miners would be about the same.
Energy use in Bitcoin has no correlation with number of transactions processed.
And we'd have to, to keep bad actors from doing similar. It's a terrible idea!