| Full text here: http://sci-hub.tw/10.1038/s41558-018-0321-8 Data & analysis is here: https://github.com/moracamilo/Bitcoin/ The argument is: 1. Assume each mining pool's users are in the pool's home country, and use their country's average mix of fuel sources, and use the hardware in supplementary table 1 (which I haven't found), then Bitcoin emitted 69 MtCO2e in 2017. 2. Assume Bitcoin's usage increases at the same rate as a sample of other technologies (television, smart phone, washer+dryer...) 3. Assume that Bitcoin's carbon footprint increases with usage. Then you can multiply the projected usage by the yearly carbon footprint, and estimate the effect on temperature, at 2°C. A good counterargument is that Bitcoin's mining footprint is not proportional to usage. It's proportional to price * block reward = profitability. However, this might balance out in the end. The block reward is decreasing exponentially every 4 years, but the price increases faster than usage. And when the block reward drops to zero, transaction fees will become the sole incentive for mining, which are proportional to usage. |