Bitcoin’s Carbon Footprint Lower Than Previously Thought


Fresh research has challenged the perception that Bitcoin (BTC) mining is irreconcilable with tackling climate change. Major science and technology magazine The New Scientist published a report on the new findings on Nov. 20.

Prior research over-reliant on “blanket” assumptions

In their study, Susanne Köhler and Massimo Pizzol at Aalborg University in Denmark have criticized the assumptions underlying earlier claims that Bitcoin’s energy consumption may be as high as 63 megatonnes of CO2 annually, the New Scientist notes.

Such estimates rest on the assumption that carbon emissions from electricity generation are uniform across China — a country that continues to command a major share of global Bitcoin mining.

Source: Susanne Köhler and Massimo Pizzol via The New Scientist 

Yet breaking down the mining landscape in China to account for regional differences presents a different picture, resulting in a significantly lower estimated global footprint for Bitcoin of 17.29 megatonnes of CO2 in 2018.

These disparities are reflected in the fact that coal-reliant Inner Mongolia accounts for 12.3% of Bitcoin mining, which translates into an out-sized 25% share of total emissions. This is counterbalanced by the reverse pattern of the hydropower-heavy region of Sichuan.

Green energy

Köhler is cited as noting that climate activists should continue to watch the Bitcoin industry — warning that electricity consumption per new Bitcoin mined is on the rise — but that they should be mindful to place it in perspective:

“On the one hand, we have these alarmist voices saying we won’t hit the Paris agreement because of bitcoin only. But on the other hand, there are a lot of voices from the Bitcoin community saying that most of the mining is done with green energy and that it’s not high impact.”

The researchers also noted that electricity consumption overwhelmingly accounts for the lion’s share of the coin’s carbon emissions — rather than the production and disposal of mining hardware, which accounts for just 1% of emissions.

As previously reported, other energy specialists have hit similarly back at the perception that high energy consumption is Bitcoin’s “Achilles Heel,” arguing in favor of shifting the debate away from energy consumption and towards where that energy is produced and how it is generated. 

This June, a fresh study found that 74.1% of Bitcoin mining is powered by renewables.