An article from a bit ago to put approximate scale of the services - https://www.theguardian.com/environment/ethicallivingblog/20...

> Climate researchers say two Google searches emit 7g of CO2 – the same as boiling an electric kettle.

> ...

> If Wissner-Gross is correct then 3,500 tonnes of CO2 (500m x 0.000007 tonnes) are emitted every day through all of us performing Google searches. Or put another way, 1.28m tonnes a year. That's about the same as Laos emits each year, the 151st biggest emitting country in the world.

Compare: https://fortune.com/2021/11/06/offsetting-bitcoins-carbon-fo...

> All told, Bitcoin emits—by Forex Suggest’s estimate—some 57 million tons of CO2 annually, more than double Ethereum’s footprint. It’s noteworthy that for Bitcoin, all that energy generates a relatively low number of transactions. Because its distributed network is so slow, its users post only around 12,000 purchases, sales, and transfers on the blockchain each hour. That’s approximately 115 million transactions a year. By contrast, Ethereum handles over four times those volumes—devouring, once again, far less than half the juice. The result: Bitcoin deploys an incredible 707 kWh of electricity per transaction, 11 times as much as Ethereum, and emits 1,061 pounds, or half a ton, of CO2 every time you tap the app to buy a latte or zap a fraction to a buddy who beat you on a golf bet. Ethereum sends less than one-tenth of that carbon skyward for each purchase or transfer it processes.

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So, roughly, bitcoin has a footprint that is ~45x larger than Google search.

Facebook is probably lighter than that, though that's only a "its probably lighter than that" guess.

Whoa, so Ethereum is burning 64 kWh per transaction?

I wonder if there is any mapping of “gas” to electricity. I guess it would have to be approximate but still, it’d be interesting to estimate how much electricity a particular smart contract consumed per execution.

This is the entire point of most PoW mechanisms. It's a way of "proving" that an miner expended a certain amount of effort or energy to validate a transaction. It also requires that expenditure to be significant enough that gaming the system is expensive. As a result most of of them scale as the effort inevitably get's easier thus ensuring that the energy required to validate a transaction will only ever be capable of growing not shrinking. If it is allowed to shrink the consensus properties start to fail. Whether you think this is a worthy use of that energy will depend on how much benefit you think the consensus properties of your particular PoW implementation are providing.

I’m not questioning PoW per se, I was just surprised it worked out to that much per transaction.

While I am sympathetic with your argument, don’t forget you’re just comparing energy consumptions.

We don’t know much about how its energy is being created. If 90% of Bitcoin’s energy use would be from renewables its CO2 footprint wouldn’t be 45x as large as that of Google.

There was a study a couple of years ago suggesting Bitcoin’s global footprint is comparable to that of a medium sized city. But its assumptions are probably outdated.

Edit: https://www.sciencedirect.com/science/article/pii/S254243511...

That green energy would have been used by someone else if BTC didn't use it. Put another way, if there had been one energy customer, X, instead of BTC + X, and availability of green energy was X + BTC/2, then fuelling BTC required generation of non-renewable energy.

That's not how markets work. Maybe on short term. If the demand for green energy is increasing due to Bitcoin, the production will also increase because it will drive profits of green energy producers.

It's more complex than that, but it's pretty much how the energy market works. Saying BTC only spends a special kind of sanctioned energy is magical thinking.

Why does BTC increase demand for green energy but not other kinds of energy? Or does it increase demand for all types of energy available in the grids in which it's generated?

> If the demand for green energy is increasing due to Bitcoin

I would much rather that the demand for green energy increase due to a desire to transition away from other energy sources.

If the demand for energy is increasing and being met with green energy without removing the other sources of energy, that's not entirely a win in my book.

> If 90% of Bitcoin’s energy use would be from renewables its CO2 footprint wouldn’t be 45x as large as that of Google.

Both Google (and Bitcoin) are optimizing for lower electrical costs - wherever that may be. Often this is associated with grids with hydroelectric power. Places like https://www.google.com/about/datacenters/locations/the-dalle...

The point isn't "this is how much CO2 google and bitcoin produce" but rather using the metric of CO2 footprint as a proxy for energy consumption to compare Bitcoin to Google to Facebook.

Whatever Bitcoin's CO2 footprint is, overall Bitcoin is consuming about 45x more power than Google over the course of a year.