> Bitcoin mining uses a mind-boggling amount of power, and we don't get anything useful for all those emissions.
I see this take quite regularly and it seems a normal response to clickbaity headlines like "BTC has same power usage as Switzerland", but I think it misses some important nuance to the debate.
* Most studies locate miners and then assume their CO2 output based on energy use assuming a general energy mix of the country, this is not useful because energy usage != CO2 output, it depends very much what energy source is used
* Miners are strongly incentivized to find the cheapest possible electricity, often means finding pockets of excess wasted energy, which is also often renewable or hydro and using it rather than letting it go to waste
* BTC can be thought of as converting frequently excess wasted units of energy into a commodity which can be sold
* The above might change and if for some reason coal became the most competitively priced energy source then this would be very bad for the environment indeed.
Whether or not BTC is useful, it undeniably holds value, in the literal sense that if I gave you 1 now you could sell it at a market rate
All the above notwithstanding, a lot of research is going into finding an alternative to Proof-of-Work that is less energy intensive and I would hope that in the future a secure alternative will be found.