A group of researchers have warned China that without more stringent regulations and policy changes, the amount of bitcoin mining performed in the country could undermine global sustainability efforts.
The energy consumption and carbon emissions associated with bitcoin mining are accelerating rapidly in China, the researchers claim in work published in Nature Communications this week.
The researchers said the majority of the mining process has been conducted in China — with miners in the country accounting for more than 75% of the bitcoin network’s hashing power. They said it can be pinned on the proximity to manufacturers of specialised hardware and access to cheap electricity.
They predict the annual energy consumption from bitcoin alone will generate 130.5 million metric tons of carbon emissions within the next three years in China alone.
“By investigating carbon emission flows of bitcoin blockchain operation in China with a simulation-based bitcoin blockchain carbon emission model, we find that without any policy interventions, the annual energy consumption of the bitcoin blockchain in China is expected to peak in 2024 at 296.59 Twh and generate 130.5 million metric tons of carbon emission correspondingly,” researchers from Tsinghua University and the Chinese Academy of Sciences said.
“Internationally, this emission output would exceed the total annualised greenhouse gas emission output of the Czech Republic and Qatar.
“Domestically, it ranks in the top 10 among 182 cities and 42 industrial sectors in China.”
The researchers said moving away from the current punitive carbon tax policy to a site regulation policy that induces changes in the energy consumption structure of the mining activities is more effective in limiting carbon emission of bitcoin blockchain operation.
They said the attractive financial incentive of bitcoin mining has caused an arms race in dedicated mining hardware.
“The mining hardware has evolved through several generations. Initially, miners used the basic Central Processing Unit (CPU) on general-purpose computers. Then, a shift was made to the Graphic Processing Unit (GPU) that offered more power and higher hash rates than the CPU,” they explained.
“Nevertheless, the rapid hardware development and fierce competition have significantly increased the capital expenditure for bitcoin mining.”
The study claims that during the period spanning 1 January 2016 and 10 June 2018, up to 13 million metric tons of CO2 emissions can be attributed to the bitcoin blockchain.
“China is a key signatory of the Paris Agreement. However, without appropriate interventions and feasible policies, the intensive bitcoin blockchain operation in China can quickly grow as a threat that could potentially undermine the emission reduction effort taken place in the country,” they said.