Cryptocurrencies, NFT, web 3.0: behind “blockchain” technologies, what is the impact for the planet?

Orn saying they are the future of the web, or talking about them as a passing fad. Often associated with cryptocurrencies, NFTs, web 3.0… Blockchains, or block chains, are both presented as a revolution in the Internet and a potential danger for our environment. Will they save or destroy our planet? Probably not either. But their effect is not neutral, and it deserves to be addressed.

Blockchain technologies have been developed since 2008. It makes it possible to exchange data peer-to-peer, verify and store this information horizontally. It is a transactional database, based on one basic principle: the consensus mechanism. To validate a transaction, it must be validated by the majority of computers on the network. There is, by definition, no centralized intermediary, but a multiplicity of terminals that act as relays and verifiers of exchanges.

Public interest in blockchains coincided with the appearance of bitcoin. This cryptocurrency is not, by definition, dependent on any central bank. Its course is therefore more variable, because it is subject to no regulation. But it was so successful that some states, such as El Salvador, adopted it as their national currency.

Powerful operation

Since this star currency, we are not counting the uses of blockchain today. To sign a contract, host a site, even certify a diploma, they guarantee trust and durability. But, as their uses increased, alarming articles and studies about their impact on the climate appeared.

The best known and most discussed example is bitcoin. To “verify” and thus secure each transaction of this virtual currency, many terminals compete. A set of transactions is called a “block”. To validate a block in a new transaction, computers must solve a complex equation and the fastest wins a cryptocurrency reward. To verify that the user is “faithful” to this chain, he must make the effort to solve the equation. This verification procedure is called proof of employment “, or proof of work, requires computers with a large computing capacity … And therefore a large consumption of electricity.

Thus bitcoin “mining farms” were born. Far from the rural aspect, these are rooms or sheds, with several computers dedicated to solving a “block”. Between the consumption of computer equipment, of cooling networks, the effect is not negligible. According to figures from the University of Cambridge on bitcoin’s electricity consumption, mining this cryptocurrency requires as much electricity per year as Pakistan and its 225 million inhabitants – or about 93 terawatt-hours ( tWh) per year. . On the other hand, it is less than the annual consumption of refrigerators in the United States (about 104 tWh).

Fossil fuels and solutions

To “mine”, and to earn from it, it is necessary to find electricity at a low cost. However, countries with cheap energy are often those that still rely heavily on highly polluting fossil fuels. On the bitcoin mining map, we can see the United States, China and Kazakhstan. Most of the electricity generation in these countries comes from oil, coal or gas. Still according to estimates from the University of Cambridge, bitcoin represents 0.09% of the world’s greenhouse gas emissions. That’s about as much as the Central African Republic or Nepal.

Not all blockchains consume as much as bitcoin. The Ethereum blockchain, for example, is both a cryptocurrency and a platform for NFTs, “smart contracts” (smart contracts), and other applications, consume less. Its currency is bitcoin’s main competitor. On September 15, 2022, Ethereum released an update that changes the way it works. “Ethereum’s energy consumption drops by about 99.95%, making Ethereum a green blockchain”, can we read on its site. how? By changing the verification mode, from “proof of work” (used by bitcoin) to “proof of stake”.

Without changing anything for the users, this new method makes the mining method, which took so long, obsolete. Through a contract – present in this blockchain – the user agrees to invest cryptocurrency capital, guaranteeing that he will carry out the task of verifying the blocks honestly and in sufficient quantity. The money can be taken from him if he does not perform his part of the contract. So, there is no need for heavy calculations to prove trust money: “The energy expenditure of Ethereum is roughly equivalent to the cost of running a small laptop computer for each node in the network,” Ethereum is accepted on its site. But it is difficult to imagine the technological change of the most important cryptocurrency, bitcoin. This would require a user consensus decision, which is already difficult to obtain. And the people who have invested in computers – sometimes in huge amounts – in the mine certainly have no desire to let them gather dust.

An important technology?

We must put bitcoin, like other blockchain uses, in context: they are tools. More or less essential tools. For example, we can question the need for NFTs (non-fungible tokens), which make it possible to obtain immaterial and unique works – images, sounds, videos, etc. – which is encoded in a unique way and registered in a blockchain. It’s a way of thinking, ultimately, a 2.0 art market… without much contribution to society.

But blockchain can also ensure the sustainability and stability of a site or data. “You have to separate the question of impact from the concept of the blockchain, which is very interesting. With its proof system and its traceability, it has a decentralized aspect that makes it resilient. In the coming world, which will certainly be more chaotic , it ensures a better maintenance of the system”predicts Frédéric Bordage, founder of the Green IT association, who is interested in digital sobriety and responsible digital technology.

Even if he thinks about it “Bitcoin has become an energy orgy for not much”he said he didn’t have any “not too scared” on the future impact on the blockchain environment. “There are “buzz” in certain uses, and even if we roast the digital resource at this time, it will be stable, to have a concrete use in people’s lives. »

Blockchains cannot be owned by anyone, and thus are safer, unlike transactions or data hosting in the hands of large companies – this data collected and stored by “GAFAM” ( Google, Amazon, Facebook, Apple, Microsoft, etc.) are at the mercy of the strategies of these companies, the ethics or the lack of skepticism of their leaders. Transactions carried out on a blockchain are also a guarantee of transparency: everyone can have access to this data. Based on trust, they can have an infinite number of uses. They could, for example, be used to implement the Paris agreement, the researchers suggest, by maintaining a carbon register.

“The problem is not blockchain as a concept. That’s the way we get, supporting Frédéric Bordage. What are we going to do here? What are economic actors to do with it? That is the question. » The impact of blockchains is still marginal, and we should not, however, forget the big polluters of today. Banks pollute more than any cryptocurrency.

“The carbon footprint of major French banks represents almost 8 times the greenhouse gas emissions of the whole of France, reports Oxfam France. At the current rate, [elles] take us towards a warming of +4°C by 2100.” In addition to being dependent on it, year after year, they continue to supply fossil fuels. The debate on these new blockchain technologies should not serve as a diversion. Real revolution or house of cards, they have to be watched… Without forgetting to watch the pollution of the industrial age, which is still huge.

Emma Bougerol

Featured image: Cryptocurrency mining farm CC BY 2.0 Marko Ahtisaari via Flickr

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