Dirty cryptocurrencies

Nov 2018
Quantification of energy and carbon costs for mining cryptocurrencies

Journal of Nature Sustainability article.

Apparantly, due to the size of the blockchain, it now costs more to mine crypto currencies than actual precious metals. Researchers calculated the average energy needed to create one US dollar's worth of cryptocurrency. They found that Bitcoin, Ethereum, Litecoin, and Monero require 17, seven, seven and 14 megajoules (MJ) of energy, respectively.

Copper (4 MJ), gold (5 MJ), platinum (7 MJ), and the rare earth oxides used in mobile phones and other electronics (9 MJ) were more energy efficient in comparison. Aluminium was the exception, using an enormous 122MJ of energy per $1 of product. The environmental impact of the cryptocurrency endeavour is also noticeable.

The authors, from Oak Ridge Institute for Science and Education in Cincinnati, Ohio, said in the paper: 'During this period, we estimate mining for all 4 cryptocurrencies was responsible for 3–15 million tonnes of CO2 emissions.' A recent study warned that the huge farms of computers used to mine Bitcoin produce the same amount of carbon dioxide per year as every car in the UK combined. They could produce enough greenhouse gases to raise global temperatures 2°C (3.6°F) within the next 15 years, experts say.