First, let's assume for a moment that this February 2021 CNBC source [1] is correct in that Bitcoin mining produces 36.94 megatons of CO2 per year. The original source the CNBC article cited can be found here: [3] (which currently pegs Bitcoin at 47.62 megatons/year).
According to the EPA, the US economy alone produced 6,558 megatons of CO2 [2] in 2019 (i.e. under pre-COVID emissions).
So, Bitcoin's CO2 annualized output as of February 2021 was 0.5% of the US economy's CO2 output from 2 years ago.
This works out to be:
* 5.6% of the US agricultural sector emissions, OR
* 4.3% of US commercial and residential building emissions (heating, cooling, waste), OR
* 2.4% of the US manufacturing industry, OR
* 2.2% of all US electricity generation, OR
* 1.9% of all US transportation emissions
According to this article from 2016 published in Environmental Research Letters [4], the US could save a combined 110 megatons of CO2 emissions simply by using better building insulation, since it would reduce heating/cooling energy expenditure. That's about 3x the Bitcoin CO2 emission rate I quoted above.
So, @SwimSwimHungry, I'll ask once again: why the outrage over cryptocurrencies? Can I expect you to have 3x the outrage over bad building insulation?
[1] https://www.cnbc.com/2021/02/05/bitcoin-btc-surge-renews-wor...
[2] https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis...
[3] https://digiconomist.net/bitcoin-energy-consumption
[4] https://iopscience.iop.org/article/10.1088/1748-9326/11/3/03...