In a new report published by CoinShares on Monday, the firm estimated that the Bitcoin (BTC) mining network emitted 42 megatons, or Mt, (1Mt = 1 million tons) of carbon dioxide, or CO2, in 2021. In context, the number amounts to less than 0.08% of the world's total emissions of 49,360 Mts of CO2 in the same year. CoinShares came to such figures using a variety of estimates regarding the efficiency of the Bitcoin network, its energy use, hardware, etc., on a global scale. As a result, it may not reflect the actual CO2 emission of the network. But the report's estimate of worldwide CO2 emission is mainly in-line with industry figures.
In addition, the report estimates the total electricity consumption of the Bitcoin network at 89 terawatt-hours (TWh), which is far lower than that of estimates put forth by an institution such as the University of Cambridge. It is especially the case, given that the Bitcoin network's hash rate has reached new all-time highs. That said, electricity consumption alone is not a true contextual measure of the Bitcoin network's environmental impact. This is because global CO2 emissions come from many aspects, such as private automobiles, for starters.