Follow

I have done a little review of the recent scientific literature on emissions from proof-of-work cryptocurrencies.
I will write a blog post about this later but tl;dr:
- In 2021, the 4 major cryptocurrencies (BTC, ETH, LTC, XMR) were responsible for about 0.5% of yearly global emissions.
- Growth in emissions is about 1.5x-2x per year for the last 4 years
- For reference, the aviation industry is responsible for 1.9% of yearly global emissions.
- Emissions from aviation only grow slowly (30% over 5 years) so at this rate, cryptocurrencies will overtake the aviation industry in emissions in 5 years.
- If this growth factor would stay around 1.5, cryptocurrencies will use about 30 GtCO2e in 15 years, that is more than twice the global emissions limit to keep warming below 1.5ºC.

So the growth in emissions from cryptocurrencies must decrease dramatically to avoid disaster.

@wim_v12e Proof-of-work is so stupid. Is there literature about proof-of-stake?

@Magess There are a few but they don't deal with the emissions because in practice all the major cryptocurrencies still use proof of work.

I had a quick look and to my surprise it is disappointing: not a single paper provides a credible analysis of the energy consumption of PoS. They simply claim it will be better than PoW.
On paper provides a simulation, but I don't find it credible as it does not examine scalability.

@Magess Ah, I found a better one, but it is a discussion paper so probably not published in any peer reviewed venue.

"We approach this research question by formalizing a basic consumption model for PoS blockchains.
Applying this model to six different PoS-based DLT systems supports the hypothesis and suggests that their energy consumption per transaction is indeed at least two to three orders of magnitude lower than that of Bitcoin."

So PoS seems 100x to 1000x lower energy per transaction than PoW

blockchain.cs.ucl.ac.uk/wp-con

@wim_v12e I'm glad someone is starting to look into it. The PoS blockchains themselves sometimes put out information about it, but they are a rather biased source. :)

If it's 100x better, what would it make the energy usage of BTC look like if that switched? Not that I think it can, but it's the only one the general public knows exists.

@Magess I don't see why they could not switch if they wanted to. It is possible to run a hybrid model PoS+PoW with any ratio, so a gradual switch would be possible.

The problem is that 100x is of course a lot better, but if the growth is strong that gets undone quickly. Suppose BTC would grow 2x per year, that would mean that in 10 years emissions would increase with 2^10 = 1000x. Even if the growth is only 20% per year, that is still 80x in 20 years.

If PoS was 1000x better than PoW then it would be all right I guess.

@wim_v12e I just think they wouldn't want to. They seem quite content with PoW being a translation of electricity into money, and even that this is the reason for its popularity.

@Magess Could be. As it is a system based on greed, it would require economical incentives to make the change. For example, rising electricity prices or rising hardware prices. OTOH, if customers ask for PoS that also provides some incentive.

climate doom, crypto - some actual numbers 

@carcinopithecus Didn't mean it to be "doom", more like a reality check.

Besides crypto, there are many other uses of electricity that are growing steeply. The same reasoning goes for all of them. But electricity generation itself is not growing very steeply. So it will be a self-limiting system in the end. But that limit will be one that is too high to meet the 1.5ºC targets, because renewables are not growing fast enough. So limiting the growth of all these things that use lots of fossil fuels is the key action.

@wim_v12e if crypto is adopted in exponential manner how its emission keeps growing linearly?
If crypto grows 2x per year is that normalized against general grow in energy consumption?
Maintaining 1.5% growth over 15 years (and above global growth) assumption will blow up like any compounded value. With such assumption any growing emission source over many years will account for almost all emissions.

@fudgel Let me try to answer in orderly fashion:

1. "if crypto is adopted in exponential manner how its emission keeps growing linearly?"
> They aren't. The current observed growth of 1.5x - 2x per year is exponential, not linear.

2. "If crypto grows 2x per year is that normalized against general grow in energy consumption?"
> No. It is purely growth in demand of electricity.

3. "Maintaining 1.5% growth over 15 years (and above global growth) assumption will blow up like any compounded value. With such assumption any growing emission source over many years will account for almost all emissions."
> 1.5% would be fine, that is only 25% over 15 years. The observed growth is much steeper, more like 150%.
There are many other uses of electricity that are growing steeply. So it will be a self-limiting system because the amount of electricity that can be generated is not growing very fast. But that limit will be one that is too high to meet the 1.5ºC targets, because renewables are not growing fast enough.

Sign in to participate in the conversation
Cybrespace

cybrespace: the social hub of the information superhighway jack in to the mastodon fediverse today and surf the dataflow through our cybrepunk, slightly glitchy web portal support us on patreon or liberapay!