On October 29th some scientists studying climate change posted a new report on Nature.com warning about the carbon footprint of Bitcoin and its potential impact on global warming.
This report infers the existing bitcoin power consumption data and various predictions of bitcoin usage over the next few years.
According to the report in 2017 among the approximately 314.2 billion cashless transactions in the world the share of Bitcoin is estimated to be around 0.033%. The report acknowledges that “accelerated growth” is common in the early stages of application of new technologies but reports that even if Bitcoin follows a lower level of “median growth” it may reach “less than 100 years” The level of total global cashless transactions.
If this vision is realized even if the adoption rate of Bitcoin is similar to some of the "slowest widely used technologies" its cumulative emissions will cause the effect of global warming to be "more than 2 degrees Celsius in 22 years" If it is adopted as quickly as possible its cumulative emissions will reach this level within "11 years." The predictions made by the carbon footprint are based on the assumption that the type of fuel used today for power generation will remain “relatively fixed” in the coming years.
For Bitcoin's current carbon footprint this report cites a recent study by Digiconomist whose "hypothesis" is
“In the bitcoin transaction verification process the cost of 60% of the economic return comes from power generation which is $0.05 per kWh and 0.7 kilograms of carbon dioxide equivalent per kWh (CO2e). Therefore it is estimated that by May 2018 Bitcoin will be used. The amount is 33.5 metric tons of carbon dioxide per year."
These climate scientists have shied away from predicting the "destiny" of bitcoin but they say that economic logic will prompt miners to move to areas with lower electricity supply costs and scientists suggest that "electric decarbonization" can help reduce Bitcoin's carbon footprint but Power decarbonization is only possible in areas where the cost of renewable energy generation is cheaper than fossil fuels.
The report acknowledges that if energy costs are still high more efficient hardware may help reduce the carbon footprint but since this is untapped hardware it cannot be hoped. The report recommends that Bitcoin "simple modifications to the entire system such as increasing the number of transactions per block or reducing the difficulty or time required to resolve the proof of the workload" to "immediately" reduce the amount of electricity used by Bitcoin.
Of course not all energy experts agree with the general view that high energy consumption is the “Achilles heel” of Bitcoin. A report published in August this year criticized the focus on the energy-intensive nature of the mining industry highlighting the importance of where and how energy is generated and believes that “electricity production can increase but the impact on the environment is minimal.”