How large is the CO2 footprint of the Bitcoin?

How large the CO2 footprint of the Biotcoin network is depends on where the computers are located and what the electricity mix looks like there. According to, BTC will change the worlds financial system. Is it worth the environmental cost?

CO2 footprint like Jordan or Hamburg: The crypto currency Bitcoin now requires around 46 terawatt hours of electricity per year for its computing operations. In order to cover this energy requirement, around 22 megatons of carbon dioxide are released annually, as the most detailed study to date of the Bitcoin’s energy balance reveals. The CO2 footprint of the crypto currency thus corresponds to that of a small country or the city of Hamburg.

Crypto currencies are in vogue, because thanks to the blockchain principle, Bitcoin, Ethereum and Co financial transactions can be processed decentrally yet securely. The catch, however, is that the necessary computing processes are complex and Bitcoin mining therefore consumes a lot of energy – and the trend is rising. Because the crypto calculations to be solved are becoming increasingly difficult, the computing power required for a Bitcoin quadrupled in 2018 alone. More information about bitcoin at

IPO and mining pool as data source

Researchers have already tried to determine how much electricity the Bitcoin network requires and what CO2 emissions it causes. However, the large Bitcoin miners in particular have so far only disclosed sparse data about their plants. But the IPO of three major manufacturers of mining hardware in 2018 has now given Christian Stoll of the Technical University of Munich and his team the chance to gain more insight.

From the documents submitted at the IPO, the researchers determined the market shares and energy efficiency of the individual computer models from Bitmain, Ebang and Canaan. To be able to calculate power consumption more accurately, they included the size and type of Bitcoin systems: “The range extends from students to gamers who make their graphics cards available for Bitcoin mining during breaks to specialized cryptomining farms,” explain Stoll and his team.

While smaller, private Bitcoin miners only need electricity for their computers, large systems have additional energy consumption for cooling, transformers and other accessories. In order to determine the proportions of the different types of miners, the scientists analysed, among other things, the distribution in the slush pool, a public association of various Bitcoin miners.

Power consumption of 46 terawatt hours

The result: In November 2018, the annual power consumption of the Bitcoin network was around 45.8 terawatt hours – assuming the lower limit of the possible range. To meet this demand, more than five large power plants have to run at full load throughout the year. Since 2016, energy consumption has also risen relatively steadily, from 345 megawatts at the end of 2016 to 5,232 megawatts at the end of 2018, as the researchers calculated.

But how does this affect the CO2 footprint of the Bitcoin system? To clarify this, the researchers determined in which countries the computers of the Bitcoin Miners are located and what the energy mix of the power grids looks like there. They localised the location of the mining facilities both via the IP addresses in the statistics of the two largest pools and via special software that detects the IP addresses of the nodes that add a new block to the Bitcoin block chain.

68 percent of computing power in Asia

The evaluation showed that 68 percent of the computing power in the Bitcoin network is concentrated in the Asian region – above all in China. A good half of the mining facilities there are located in the hydropower-supplied south of China, the rest, however, work in northern China, where coal-fired power supplies a large part of the energy. For the CO2 footprint of the Bitcoin miners in China, the researchers have thus arrived at a balance of 550 grams of CO2 per kilowatt hour of electricity consumed.

Another 17 percent of the computing power of the Bitcoin miners is in Europe, 15 percent in North America, according to Stoll and his team. They also determined the CO2 footprint from the electricity mix of these regions.

CO2 footprint like Hamburg

Overall, the researchers come to the conclusion that the Bitcoin system produces between 22 and 22.9 megatons of carbon dioxide per year. “This corresponds to an amount that lies between the CO2 emissions of Jordan and Sri Lanka,” says Stoll and his colleagues. “The CO2 equivalent of the Bitcoin thus lies between 82 and 83 in the list of global emitters. In Germany, this value would be comparable with the CO2 footprint of the city of Hamburg.

“Even if there are more important factors for climate change: The CO2 footprint is so large that it provides sufficient reason to discuss the regulation of crypto-mining at sites with CO2-intensive electricity production,” says Stoll. The scientists argue that in future the mining facilities of Bitcoin and other crypto currencies should be relocated even more to locations where sufficient electricity from renewable energies is available.