Environmental science: Climate impacts of Bitcoin mining in China

The energy consumption and carbon emissions associated with Bitcoin mining are accelerating rapidly in China, according to a new study published in Nature Communications. Without more stringent regulations and policy changes, these impacts could undermine global sustainability efforts.

The Bitcoin cryptocurrency relies upon blockchain technology, which enables publicly recorded peer-to-peer transfers through encrypted computer networks without the need for a centralized authority such as a bank. Mining Bitcoin requires constantly expending and/or expanding computer processing power, which is associated with increasing energy consumption.

Dabo Guan, Shouyang Wang and colleagues track carbon emission flows of Bitcoin blockchain operations in China with a simulated carbon emission model. Given the current trends in Bitcoin mining, they estimate that the energy consumption from this process will peak in 2024 at around 297 terawatt-hours and will generate around 130 million metric tons of carbon emissions. These amounts exceed the entire annual greenhouse gas emissions outputs of entire mid-sized countries in Europe, such as Italy or the Czech Republic. The authors suggest that policy interventions are critical to reduce these impacts. Feeding different scenarios into their model, however, they find that current policies like carbon taxation are not effective at curbing emissions from the Bitcoin industry. Instead, they find that individual site regulation policies for Bitcoin miners represent the best way to alter the current energy consumption structure and reduce future emissions from the blockchain operation.

After the embargo ends, the full paper will be available at: https://www.nature.com/articles/s41467-021-22256-3