A transaction on the Lightning Network produces less carbon emissions than posting on social media or even breathing for a few hours, according to Bitcoin exchange CoinCorner’s latest research.
The research authors, including CoinCorner CEO Danny Scott, agree with many in the Bitcoin community that judging Bitcoin or Lightning's energy use and emissions on a per-transaction basis is flawed, especially since a disproportionate use of that energy comes from fixed costs such as mining and securing the network, not individual transactions.
The calculation below shows that only 0.0099 grams of carbon emissions come from sending an actual transaction itself, versus 144.560 grams of CO2 produced from running the entire Bitcoin and Lightning infrastructure for a year.
This shows that a sharp increase in the number of Bitcoin transactions would not significantly impact the overall emissions of the network. Network detractors tend to assume that transaction numbers and emissions scale linearly. In reality, as transactions scale up, Lightning would become more efficient on a per-transaction basis due to economies of scale.
The calculations also show that even with fixed energy expenditures from mining and infrastructure included on a per transaction basis, Lightning is still extremely energy efficient compared to other activities and products we take for granted.
For example, the process involved in producing one glass of orange juice uses as much energy as ten Lightning transactions, each of which could theoretically transfer millions of dollars of value.
One particularly jarring example shows the incredibly high CO2 costs associated with producing a supposedly eco-friendly electric vehicle. The E.U. estimated average for electric vehicle production is a whopping 18,750,000 grams of CO2 per car. That is the equivalent of 129,704 Lightning transactions.
These numbers are incongruous with Elon's infamous tweet announcing Tesla's suspension of Bitcoin payments for environmental reasons. Even if Tesla accepted Lightning payments for all of its roughly 499,535 vehicle sales in 2020, the CO2 emissions from the transactions would barely equal that of producing just four Tesla vehicles!
Perhaps the most fitting carbon emissions example is that of breathing itself. According to CoinCorner's research, roughly one day of breathing produces as much CO2 as seven Lightning transactions. In other words, just being alive for 3.5 hours emits the same amount of CO2 as a single Lightning transaction.
One can hope that the cited data sources and calculations will help to dispel future FUD regarding the environmental impact of Bitcoin, particularly when it comes to scaling transactions without raising emissions in a significant way.
The authors point out that "when broken down even on a purely transactional level the carbon emissions are comparable or even lower than some everyday activities that few would describe as excessive energy use."
Further, Bitcoin and Lightning do all this while also providing "the most secure computer network in the world, relying on and discriminating against no one."