Bitcoin miners have emitted almost 200 million tonnes of carbon dioxide in the cryptocurrency鈥檚 short history, researchers at the University of Cambridge have calculated. Their estimate for the 13 years since bitcoin launched exceeds the emissions of the whole country of Colombia during 2018.
The university set up the (CBECI) in 2019 to provide hard data on bitcoin that would allow people to properly assess its environmental and economic impacts. Initially, it produced estimates of the network鈥檚 total electricity demand. Then, by adding data from large numbers of bitcoin miners, it was able to collate information on the energy mix used and eventually quantify the mining volumes for each country around the world.
The CBECI team has now been able to estimate by using all of that data and a model that includes the energy consumption and mining power of various types of mining hardware, the current price of bitcoin and the point at which certain machinery becomes profitable to run in various scenarios.
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By the middle of September, the team estimates that 199.65 million tonnes of CO2 emissions could be attributed to the bitcoin network. Because adoption grew over time, 92 per cent of those emissions occurred in the past four years.
This year, the network is forecast to emit the equivalent of 48.35 million tonnes of CO2, which the team says represents approximately 0.1 per cent of global greenhouse gas emissions or about half that of global gold mining.
Fossil fuels account for 62.4 per cent of the electricity mix used to mine bitcoin and sustainable energy sources 37.6 per cent.
The estimates differ from those provided by industry group the Bitcoin Mining Council, which has said .
at the Cambridge Centre for Alternative Finance, which runs the CBECI, says the two organisations have different methodologies. 鈥淚t鈥檚 not our aim to either say bitcoin is great or it鈥檚 terrible,鈥� he says. 鈥淲e have a neutral stance and we always strive to represent the reality as accurately as possible. There鈥檚 a public interest in this topic.鈥�
Although the cryptocurrency鈥檚 price and popularity have grown over time, there are indications that they have peaked, at least temporarily, potentially due to rising energy costs. In August last year, the price of a single bitcoin exceeded 拢50,000, but it currently sits at less than 拢20,000.
The CBECI estimate that the bitcoin network will cause 48.35 million tonnes of CO2 emissions this year is 14.1 per cent lower than the estimated emissions in 2021. The sharp decline in mining revenue has led to the retirement of older and less-efficient hardware, says Neumueller, but this may be temporary.
