Bitcoin mining is notoriously energy-intensive, but new research suggests it could contribute as much to climate change as the beef or crude oil industry, according to one estimate. In a study published Thursday in Scientific reportsthe researchers compared the approximate environmental cost of digital currency mining to the impact of other industries and countries.
“Within the general public, I think a lot of people are still struggling with what bitcoin is,” said Benjamin Jones, an environmental economist at the University of New Mexico and co-author of the study. popular scienceIt’s Miyo McGinn. “But we have to be aware of the huge impact this has on the environment. It is very damaging. »
Bitcoin mining is the process by which new currency comes into circulation and transactions are verified. This process requires specialized computers that solve complex mathematical problems. The first miner to solve a given problem wins a predetermined amount of digital coins, written new scientistis Corryn Wetzel. Miners with the most powerful computers can make more guesses, allowing them to solve a problem faster and increasing their chances of winning.
“Because it’s worth a lot of money, you have a lot of people getting into this guessing game,” Jones said. new scientist. “It uses a lot of electricity, and most of that electricity comes from fossil fuels.”
To calculate the impact of mining, the researchers looked at the number of bitcoins mined daily between 2016 and 2021. They took into account the amount and type of energy used by miners, as well as their locations to estimate emissions per piece, per new scientist.
Using the social cost of carbon, a common metric to assess the financial damage caused by greenhouse gases, the researchers calculated the climate cost of Bitcoin. On average, they found that for every dollar of bitcoin value produced, the process resulted in 35 cents of global climate damage, or 35% of its market value. By comparison, weather damage from beef reached 33% of its market value, and damage from gasoline produced from crude oil was 41%.
In May 2020, Bitcoin damage peaked at 156% of the coin price, according to the study.
“We find multiple instances between 2016 and 2021 where bitcoin is more damaging to the climate than a single bitcoin is actually worth,” Jones said in a statement. “In other words, Bitcoin mining, in some cases, creates climate damage greater than the value of a coin. This is extremely troubling from a sustainability perspective.
Carbon emissions from mining a single bitcoin have increased from 0.9 tons in 2016 to 113 tons in 2021, a 126-fold increase. The industry’s annual carbon footprint is comparable to that of the Greece, according to Digiconomist. And in 2020 Bitcoin used 75.4 terawatt hours of electricity, more than Austria (69.9) or Portugal (48.4).
But the environmental impact of mining this cryptocurrency does not just come from its emissions. “In addition to energy consumption, you need to consider hardware use and electronic waste,” says Alex de Vries, a researcher in digital currencies at Vrije Universiteit Amsterdam in the Netherlands who was not involved. to the new search, for popular science.
The equipment used for mining is highly specialized – it is only used to mine bitcoins, says de Vries popular science. Therefore, computer chips are obsolete in just one and a half years, and then they become waste. A single Bitcoin transaction creates about 400 grams of e-waste, which is equivalent to 2.44 iPhone 12 devices, according to Digiconomist, which de Vries founded.
“[Computing] devices end up in unknown locations for unknown durations, potentially releasing toxic materials into soil and water,” he said. popular science. “Or they are thrown into an incinerator and the toxic materials are released into the air.”
It is possible to produce cryptocurrency in a less energy-intensive way: another popular cryptocurrency, Ethereum, made a change in September that was supposed to reduce its electricity consumption by 99%. Jones tells new scientist he hopes Bitcoin will make a similar move.
At the moment, however, the climate impact of mining these coins remains high. The authors write that their findings raise a “set of sustainability red flags.” Bitcoin proponents have called the virtual currency “digital gold”. But “from a climate damage perspective,” the authors write, “it works more like ‘digital raw’.”