A current current of concern within the technological world is related to the emission of carbon and pollutants due to digital activities, a concern that has reached the world of blockchains, giving rise to the development of the well-known negative carbon blockchains. The goal in any case is reduce the emission of carbon and other pollutants as much as possible, thus collaborating with the preservation of the environment of our planet.
To achieve this, most carbon negative blockchains look for one thing: consume less energy offering more performance. Generally, they do this through faster and less intensive consensus mechanisms, as in the case of Proof of Stake (PoS), Delegated Proof of Stake (DPoS), Proof of Authority (PoA) and the use of faster and more permissive BFT (Byzantine Fault Tolerance) solutions (in the sense of not being as tolerant of this type of failure). Another model to achieve this is through sidechains that speed up operations and allow their users to carry out transactions with reduced energy costs.
In any case, the development of negative carbon blockchain solutions always aims to build systems with lower or even non-existent levels of decentralization, but which, consequently, offer us more performance. But why is this so worrying now? What is the scope and what advantages/disadvantages do these systems offer? Well, let's examine this situation.
An increasingly relevant concern
Concern for the environment has become a fundamental pillar for many industries. Some of them, highly polluting (such as the oil company) have done their bit to make their activities, products, by-products and waste, to a certain extent, less polluting than they should be without proper treatment.
Of course, there are industries where a minimum pro-environment effort it has a high impact, but in others, that impact may be minimal or even negligible, regardless of the amount of money that can be invested in such activities. The main reason for this difference has to do precisely with our technological progress, since this is the limiting point on what technologies can be applied to optimize processes and make them less polluting.
It is precisely this technological advance that has given rise to the negative carbon blockchain, or rather, reduced emission blockchain. Take for example networks like the Lightning Network. Yes ok Lightning Network Relying on Bitcoin, a highly energy-intensive network, LN actually offers services with greatly reduced energy costs, while offering speed and security of operations. If we add to that the fact that most LN nodes run in renewable energy environments, then we are looking at a carbon-negative or low-emission “blockchain” (actually, LN is a sidechain).
The same situation, for example, can be seen in Ethereum, which left the PoW model to move to the PoS model, reducing its energy needs by more than 97% in the process. In both cases, energy emissions and consumption have been reduced, following their own objectives and roadmap, but with a very similar impact.
Important points of negative carbon networks
- Although energy consumption is reduced, many carbon negative blockchains tend to choose models that recentralize or, at least, decrease its level of decentralization. Ethereum is perhaps the clearest example of this, since the network is currently centralized to dangerous levels (more than 50% of the nodes are in the United States and deployed on AWS). This scheme is repeated with more or less impact in other networks, for example, Solana, Harmony, EOS, Polygon, Arbitrum, Algorand, Ripple, Polkadot, Avalanche, Cosmos, among others.
- Consensus models and algorithms focused on speed and scalability, many times they are not so resistant and safe like their counterparts more focused on correctness and greater decentralization. A good example of this can be seen between Bitcoin and Solana. Bitcoin has been a blockchain network with a high level of security and an enviable uptime of more than 99% in 13 years. By comparison, Solana often suffers outages and has even needed to “reboot the blockchain” to get back up and running. Of course, this situation has changed a lot and Solana has gained stability, but the project is still a Beta, showing that much development is needed for it.
- Less decentralization opens the doors to apply regulations that can threaten the freedom to access blockchain services, thus promoting the censorship about it. An example of this can be seen in Ethereum, where more than 70% of the operations carried out on the network now go through an OFAC Compliance process in its validator nodes. In MevWatch you can observe how this situation evolves in real time.
Can a blockchain really be carbon negative?
Now, the question remains: Can a blockchain really be carbon negative? The short answer is: No. The reason is simple: Any activity in the real or digital world always carries a carbon footprint that cannot be erased, even if you optimize the process that makes it possible 100%. In other words, any activity always carries a polluting footprint, which may be directly or indirectly related to the activity and which may or may not be optimized so that it generates the least possible pollution.
But let's explain this in a clearer and more concise way. Take for example Ethereum and its PoS system. They have certainly reduced their carbon footprint by reducing their energy consumption, but it has not become a carbon negative blockchain, in fact, it has only transferred the energy consumption directly related to its operation to a third party, node hosting.
With Ethereum as a PoW network, we were able to know how much computing power was in the network and from there we could extrapolate data necessary to know how much energy is spent and how much carbon that consumption means. We were able to know, even roughly, how much CO2 Ethereum emitted.
But now, that is not possible because how much power does a VM instance of an Ethereum validator node on AWS actually consume? The truth is that no one knows for sure, as it is an Amazon trade secret, but we are talking about hundreds of thousands of servers running at the same time, requiring cooling and power-hungry support equipment.
In fact, this secret has had several attempts to study with some interesting estimates who come to the same conclusion: it is not possible to know exactly. At this point, Ethereum has gone from a publicly auditable model (where we could approximately know network consumption with a good margin of success) to a gray one, where such auditability is not entirely possible and where the margin of error is older.
This is in terms of energy, without taking into account that things like hardware and infrastructure need elements that have to be created and that generally also have their own carbon footprint: CPUs, RAM memories, etc. This is a reality that affects the entire technology industry, whether it is crypto or not, where, for example, creating a chip requires a huge expenditure of energy and valuable resources (for example, more than 120 liters of purified water are needed to make the wafer). a single chip and a factory can require up to 50 MWh a year of electricity).
This reality is what divides many personalities in the community and better positions the concept of: reduced emission blockchain.
Thoroughly reviewing Bitcoin mining consumption
Taking all this into account, we can see that different industries seek to adapt to an increasingly relevant concern in our world: protecting our environment and the future of planet earth. And this is a reality that is replicated in the blockchain world. Let's take as an example the impact that cryptocurrency mining has on the world at the level of carbon emissions. For this example we will use Bitcoin and the index Cambridge Bitcoin Electricity Consumption Index (CBECI).
According to the data collected by this index, until 2021 Bitcoin has consumed 305 TWh of energy, with 2021 being the year with the highest consumption, with a total of 104,89 TWh of energy consumed that year. That means that a third of all the accumulated energy consumption of Bitcoin was carried out in one year, that of 2021. But this is consumption. How much CO2 emission does all this mean?
For this we take this formula:
CO2 emission = 884,2 lbs CO2/MWh × 1 metric ton/2,204.6 kg × 1/(1-0.073) MWh generated/distributed × 1 MWh/1,000 kWh
CO2 emission = 4.33 × 10-4 metric tons CO2/ kWh
It allows us to calculate the average carbon emission taking into account energy consumption (described in MWh), without taking into account renewable or nuclear energy sources. Of course, this formula is an average and you have to understand that there are other factors that affect the emission, but it will give us an idea of “how much CO2 Bitcoin has emitted during 13 years of existence”.
Thus we have that:
Energy Consumption BTC = 305 TWh = 305.000.000 MWh
BTC CO2 Emission = (BTC Energy Consumption * 884,2 lbs CO2/MWh) × 1 metric ton/2,204.6 lbs × 1/(1-0.073) MWh generated/distributed × 1 MWh/1,000 kWh
BTC CO2 emission = (305.000.000 MWh * 884,2 lbs CO2/MWh) × 1 metric ton/2,204.6 lbs × 1/(1-0.073) MWh generated/distributed × 1 MWh/1,000 kWh
BTC CO2 emission = 131.959,55 metric tons of CO2
Put like that, it seems that BTC and its mining are a perfect pollution machine. But if we look at the global emission data, we find that the entire world, in 2021 alone, emitted a total of 37,12 billion metric tons of CO2, so those 131.959,55 metric tons of CO2 emitted by BTC over 13 years, represents only 0,0004% of all total CO2 emissions globally in a single year (2021).
But this is a bit false data. The reality is that a good part of Bitcoin mining is done using renewable energy and therefore carbon neutral (without CO2 emissions). In fact, the University of Cambridge indicates that about 37% of all Bitcoin energy consumption (35% of those 305 TWh) is of renewable origin and therefore carbon neutral. Meanwhile he Bitcoin Mining Council (BMC) indicates that by at least 2021, 56% of Bitcoin mining was carbon neutral.
Conclusions
The issue of energy consumption and the carbon footprint of blockchains It is a complex and contentious issue. But the reality is, that although developments that seek to reduce the carbon footprint are good, they cannot simply be ignored and destroy the decentralization and security that blockchain allows us. To fall for that would be to lose all the advancement in this technology and what it has to offer to the world.
Solutions such as those proposed by Bitcoin (with a high consumption PoW network and a low consumption sidechain) may seem controversial due to their "high consumption", but in view of the aforementioned data, it is clear that this high consumption is not such. , and that in reality there are much more relevant and dangerous carbon emitters, who are not even mentioned.
In any case, it is always good to keep in mind the premise of "do not trust, verify", not only with blockchain transactions, but also with what can be read in many media about this situation on blockchain and its real impact on the environment. atmosphere.