The CO2 calculations are based on average mining facilities carbon intensity of 0.475 tCO2/MWh; average mining CO2 footprint of 183 t per BTC mined, average prices of European/Chinese/US carbon allowances of €50/$20/$4 in 2021 Q1-Q2, and average EU/CN/US green cert prices spot+forward of €2/$2/$1 respectively.