Energy demands for the extraction of four major cryptocurrencies, including Bitcoin, outweighed the energy costs of extracting real metals such as gold and copper, according to US environmental researchers.
Data mining cryptocurrencies involve increasingly complex calculations to confirm new transactions and add them to the decentralized accounting on which a cryptocurrency operates.
It is a process that can be done on scales and variable calculation levels, with Unicef Australia that even implemented a browser-based version that allowed donors to use the processing power of their computer to extract Monero on behalf of the 39, charity.
Researchers at the Oak Ridge Institute for Science and Education have now compared the amount of energy needed to perform these authentication processes with respect to the energy requirements for mining real metals and minerals.
The document published today in Springer Nature found that between January 1, 2016 and June 30, 2018, 17 megajoules (MJ) were needed to produce $ 1 of bitcoin, 7 MJ for Ethereum and Litecoin and 14 MJ for Monero.
While the value of 1 US dollar of aluminum produced 122 MJ to produce, the other four metals tested were equal to or lower than the energy requirements for cryptocurrencies.
Platinum bound with Ethereum and Litecoin at 7 MJ, with gold arriving just behind 5 MJ.
Copper had the least in the 4 MJ poll, and common rare earth oxides in electronic devices required 9 MJ – even less than Monero and Ethereum.
The authors of the document, Max Krause and Thabet Tolaymat, acknowledged that while cryptocurrency prices were quite volatile, hashrates for three of the study's four crypto-currencies showed a steady upward trend, suggesting an upward trend similar in the amount of energy required.
They also extrapolated the data to the CO2 emissions released by the extraction of cryptocurrencies, estimating that the global extraction operations generated between 3 and 15 million tons of CO2 during the 2.5-year period of the study.
However, differences in electricity production between countries mean that a crude currency extracted in China has generated four times as much CO2 as a coin extracted in Canada.