[FabHK]

It is a bit annoying that you assume that people critical of cryptocurrencies and specifically Bitcoin's environmental footprint are uneducated about the issues. It is not a myth. BTC's environmental footprint is preposterous. It's estimated that the network currently runs at 165 TWh/a, or around 19 GW, which means that one transaction uses around 5 GJ or 1500 kWh, and produces 800 kg of CO2, and 250 g of electronic waste.

For keeping track of a ledger that one dude in a basement with an Excel spreadsheet could keep track of, more or less.

[dragonwriter]

> For keeping track of a ledger that one dude in a basement with an Excel spreadsheet could keep track of, more or less.

No, for protecting against the untrustworthiness of that one guy in his basement. You may disagree with the value of that function, but that's what cryptocurrency provides.

[thow-58d4e8b]

To underline how preposterous the whole PoW is - BTC is mined by hardware that consumes 2000-3000W each, all the while vast majority of these machines never mine a single block

[plebianRube]

Technically half true, they share the processing load of guessing the next valid block, and then share the profit when the one piece of hardware finally guessed it.

[yawaworht1978]

I do not remember when a Chinese ASIC miner ever shared something while I was mining with a laptop.

Network shares the load but winner takes it all, i thought.

[plebianRube]

Those were the bad old days. There are pools now, like the old Seti@Home program. If your mining pool wins you get the percentage of the reward relative to the hashes you tried.

You can try to go it alone but your chances of finding the block reward are incomprehensibly low.

[poontang1]

Measuring energy use per transactions makes no sense, as mining energy consumption is not related to the number of transactions processed.

Also a huge portion of the energy used by bitcoin would otherwise be wasted.

Also your figures are egregiously off and taken from flawed estimates

https://nydig.com/wp-content/uploads/2021/09/NYDIG-Bitcoin-N...

[FabHK]

> Measuring energy use per transactions makes no sense

I am well aware of the difference between average and marginal energy use. This would be particularly relevant if the blocks were not full, but mined anyway, so that any additional transaction could've been included "for free". However, more often than not, that's not the case, but the mempool is non-empty, and the constraint (of max transactions per block) is binding. [1]

Thus, one can not trivially argue that the marginal cost of a transaction is zero.

Next, yes, my figures (165 TWh/a = 19 GW) from Digiconomist [2]) are at the upper end of the estimates, but other figures (eg Cambridge Bitcoin Electricity Consumption Index) estimate 100 TWh/a, with reasonable bounds of 36 to 376 TWh/a, so 12 to 28 GW, so are largely in alignment, modulo a factor of 2. (Note that your source is also within a factor of 3 of those estimates, pegging BTC at 0.2% of global electricity consumption.)

At any rate, the average cost is just preposterous, even if off by a factor of 3.

[1] see for example https://jochen-hoenicke.de/queue/#BTC,1w,count

[2] https://digiconomist.net/bitcoin-energy-consumption/

[3] https://cbeci.org

[jhgb]

> Measuring energy use per transactions makes no sense, as mining energy consumption is not related to the number of transactions processed.

Sure, measure energy use per amount of money transferred. That's not going to be very nice either.

> Also a huge portion of the energy used by bitcoin would otherwise be wasted.

Oh, come on. Now you're just trolling. It would have been used for something else that most likely wouldn't be waste, like in factories or in hospitals and such.

[macinjosh]

Give me a break. Power consumption numbers are completely meaningless in this argument. Power usage does not correlate directly to CO2 emissions. Crypto can and does run on renewables. If we were serious about fixing climate change we'd stop all air traffic tomorrow. In reality, the climate issue is just a convenient political bludgeon.

[FabHK]

> Crypto can and does run on renewables.

Energy is fungible.

> If we were serious about fixing climate change we'd stop all air traffic tomorrow.

The fashion industry alone has more climate impact than air traffic and maritime traffic together. Aviation contributes around 1% of air pollution (though 5% of greenhouse effect, due to high altitudes).

But all of those (transport, fashion) provide utility. BTC usurps nearly 1% of world electricity without providing commensurate discernible utility.

[plebianRube]

I'm sure people who don't fly or follow fashion feel the same way about the perceived utility.

I for one think not having to pay 20% for a remmitance for someone who is trying to help their famiy in another country has huge utility, maybe others disagree.

[jhgb]

CO2 emissions are Θ(P). I don't see how you could say this "does not correlate directly to CO2 emissions".

[macinjosh]

Its not complicated. It is not necessary for crypto PoW to be powered by CO2 emitting fuels. It can be powered with renewables. Therefore the power usage of Bitcoin can't be used to infer its environmental impact. You need to know how much of that usage was on the back of fossil fuels.

[UncleMeat]

Energy is fungible. Unless those renewable-generated watts were unable to be used for other things, then all marginal use of energy uses emitting sources, since we are not yet at 100% green energy. There are a few exceptions where mining is done on grids that are at 100% green energy, but this is not the norm.

[throwaway19841]

Sure in theory. In reality not all energy is fungible because not all power generating systems in the world are connected. If I stand up a geo-thermal farm to run my crypto mining operation that power would not have been available to the grid anyway because the economic incentive to build the power station was crypto, not selling it to the grid.

[UncleMeat]

These cases exist, but they are not the dominant form of mining. If all mining was done in such circumstances (and the energy source couldn't be connected to a useful grid) then people wouldn't be as upset.

[jhgb]

> It is not necessary for crypto PoW to be powered by CO2 emitting fuels. It can be powered with renewables.

That's completely irrelevant for the correlation. Renewables are theta-bound by fossil fuels, and fossil fuels are theta-bound by renewables. Only at zero emissions for a source this would stop being true. This is first semester math.

[throwaway19841]

> Only at zero emissions for a source this would stop being true

There are plenty of crypto operations that have their own, renewable power sources that operate in a closed zero emission fashion.

[jhgb]

> renewable power sources that operate in a closed zero emission fashion

If you mean operational emissions, then this is a trivial statement. If you mean total emissions, then this is a wrong statement, unless these people manufactured their own generators using zero emissions in the process.

[cecilpl2]

Energy is fungible.

If base load were to drop due to crypto miners being turned off, the energy with highest marginal cost would be turned off, which means fossil fuels, not renewables.

[throwaway19841]

The fungibility argument doesn't work when you consider that not all power generation in the world is connected to the same grid. There are crypto operations that use their own renewable power infrastructure. That energy never would have made it to the grid because there was no incentive for it to be put there (otherwise it would already have been there). The incentive is to use it for crypto not your mom's blender.