What Is The Carbon Footprint Of A Bitcoin?

Just how much carbon dioxide do we produce when we mine a bitcoin? It's becoming an increasingly important question.

Other attempts have been made to nail down the cost of the bitcoin network in terms of carbon emissions and/or energy used, but it's a tricky business, says Guy Lane, founder of sustainability advisory service Sea O2. Based in Brisbane, Australia, Lane is also the founder of Bitcarbon.org.

"Of course, bitcoin is mined everywhere from data centres, distributed locations, working pools, rigs set up in garages and even on PCs that have been hijacked by bots," Lane says.

His method is based on the premise that miners will spend up to 90% of the cost of a bitcoin on the electricity used to mine it.

The method maps these figures against average electricity prices, to produce an average carbon intensity of 6.98 kg of CO2 for every dollar that is spent on electricity used for mining Bitcoin.

Lane last ran this model in December, when bitcoin was priced at $1000, and calculated that the entire bitcoin network was putting out about as much carbon as Cyprus.

For one thing, it doesn't account for the fact that miners might be willing to spend more electricity mining a bitcoin than the current value of that coin, in the hope that it may increase.

Another way to look at carbon output for bitcoin mining is to go and ask a professional miner.

Dave Carlson, founder of Megabigpower, runs a massive bitcoin mining datacentre in Washington state.

If you are burning fossil fuels for your bitcoins, then using just over a sixth of a ton of carbon for a single bitcoin isn't good, given that the network is churning out 150 of them per hour.