In 2008, in response to the Great Financial Crisis, Satoshi Nakamoto released a whitepaper called “Bitcoin: A Peer-to-Peer Electronic Cash System”. What followed was the emergence of a movement that has ever since kept disputing the role of the banking sector and well-paid intermediaries. Of course, we are talking about Bitcoin, blockchain, and most importantly, the entire decentralized finance (DeFi) industry. While visionaries and tech-nerds hail it as the dawn of a more democratized future, critics, often superficially informed, decry the technology for its intangibility, pointless waste of energy, and vast carbon footprint. So what is this environmental debate all about? - Author: Elias Mendel
Before engaging in the aforementioned discussion, let us rewind and quickly look at the DeFi space itself. While Bitcoin is the most known cryptocurrency, with its aspiration to become the leading global payment system accessible to each and everyone, there have emerged plenty of other ambitious projects. In a nutshell, DeFi describes a movement striving to develop a new financial system that does not rely on any “too big to fail” institutions, intermediaries and central authorities, that is open to anyone.
At its core is the blockchain technology, a decentralized way of storing data into blocks by distributing numerous copies of it among a peer-to-peer network, secured through cryptography. In order to allow for this technology to offer more functionalities than mere payment transactions, projects like Ethereum - the backbone of DeFi - or Cardano incorporate extensive Smart Contract functionalities, which make it possible to map more complex business models on a blockchain as well.
A key issue any digital currency has to face is the so-called double spending problem. As the money only exists virtually, who is to prevent a malicious party from simultaneously spending the very same unit of currency more than once?. Blockchains rely on a consensus mechanism specifically designed to stave off attacks like this. The two major ones are proof of stake (PoS) and proof of work (PoW).
Proof of stake is built upon validators that verify transactions and add new blocks. Validators have a significant stake in the project’s native coin, and hence it is assumed that consciously weakening the network by including fraudulent transactions is not likely to occur, since it would result in the validators losing their staked funds. This mechanism consumes very little energy, and is thus considered fairly environmentally friendly, even amongst critics.
On the other hand, there is proof of work, which requires “miners” who are responsible for adding blocks and keeping the network secured, to solve complex mathematical problems by sacrificing substantial amounts of energy and computational power. That way, they are calculating quintillions of hashes - a mathematical function that converts any input into an encrypted output with a predetermined length - every second. This massive need of energy is supposed to deter network participants from acting maliciously by tampering with the transactions history.
And it is exactly this huge amount of energy that is often deemed a fatal flaw in the likes of Ethereum and Bitcoin, preventing them from becoming even more adopted. But before coming to hasty conclusions, let us take a look at some crucial metrics.
Figure 1: Annual GHG Emissions of Ethereum, Bitcoin, and more
A further argument made on occasion is that the banking system serves way more people, so it is acceptable if they emit more carbonic acid. To scrutinize this, let us make a simple calculation.
As of 2021, at least 300 million people use cryptocurrencies in one way or another:
109 / 300 = 0.36
That means each user on average is responsible for roughly ⅓ of a ton of carbon released into the atmosphere.
If we compare this (assuming about 4 billion people make use of banking services) with
1,368 / 4,000 = 0.34
we see that the numbers hardly differ.
Equally interesting is the fact that in terms of “environmental scalability”, an ever growing user base of cryptocurrency will barely enlarge its carbon footprint, since - at latest with Ethereum 2.0 which is set to slash ETH’s energy consumption by 99% - the majority of projects in the industry will operate using PoS and other, more sustainable consensus mechanisms (e.g. Proof of Authority, Delegated Proof of Stake).
The University of Cambridge, while conducting their 3rd Global Cryptoasset Benchmarking Study in September 2020, found that about 39% of all energy consumption by PoW blockchains originate from renewable sources, with 76% of all miners utilizing renewables as part of their power mix. Figure 2: Composition of the PoW energy mix
However, there are, for example, also other studies claiming that even as much as 74% of all Bitcoin mining is powered by renewable energy sources.
Furthermore, previous mining epicenters such as Sichuan and Yunnan (their future role remains to be seen after the Chinese government banned Bitcoin mining) excessively use otherwise wasted hydroelectric power, making up for almost 10% of global mining capacities in the dry season, and up to 50% during the rainy wet season respectively.
Assuming that Bitcoin’s energy consumption, and more importantly its carbon footprint will grow exponentially lacks taking into account several important developments. A 2018 study even claimed that Bitcoin emissions alone might push global warming 2 degree Celsius above pre-industrial levels.
Let’s look at the facts. Continuously dropping prices and hence affordability of renewable energies poses a clear incentive for miners to shift increasingly to sustainable power sources - the reliance on fossil fuels will keep diminishing. There are even initiatives like the Crypto Climate Accord rooting for a cryptocurrency industry that accomplishes net-zero emissions by 2030.
And with Layer2 solutions like the Lightning network finding more and more adoption, Bitcoin’s scalability does not have to come at the environment’s expense.
Another point often disregarded is, that, in its essence, PoW is about energy usage on purpose. It is about the process of transforming energy by solving cryptographic puzzles into a digital commodity. The sum of expended energy to build this “ecosystem” is part of what attaches inherent value to it, what makes bitcoin a contender for “digital gold”. It is a feature, not a flaw, securing the entire network as costly computations and equipment prove transparently that work has been put in.
And maybe it is also one of the reasons that helped cryptocurrencies gain more traction in the first place. The real focus should not lie on the energy usage as such, but rather shift towards where that energy comes from and what needs to change for a greener future.
The DeFi industry is pursuing bold objectives, and as always, this comes at a certain cost.
Projects whose seamless running requires more energy consumption than that of countries like Sweden, Argentina, or the Netherlands, along with the consequential carbon emissions, have sparked numerous heated debates in the past months and years. While both supporters and critics have valid arguments, there are some indisputable facts and developments we considered worth highlighting in this article.
As less energy-intensive consensus mechanisms enjoy rising adoption and clean energy use becomes growingly accessible, we are convinced there is reason to believe that a greener future and the further democratization of finance can go hand in hand.
About Sharpe Explorer: At Sharpe Explorer, we help our customers leverage the crypto and DeFi revolution to access predictable returns, optimize their portfolio and gain a competitive advantage. Our mission is to provide the best and most trusted user experience for investors in the market. We are going to be the one-stop shop for the focused and comprehensive assessment of any DeFi asset. Sharpe Explorer is going to open the door to the world of DeFi and will give you direct access to wallets and DeFi protocols.
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Elias Mendel studies International Business and Economics at the University of Applied Sciences Schmalkalden. Currently, he works on several projects dealing with DLT, digital assets, and blockchain. You can contact him via email.