Can we do it without burning the energy of a moderately sized developed nation? BTC used as much power as Greece or Australia by some estimates last year. [0]
[0] https://www.eia.gov/todayinenergy/detail.php?id=61364#:~:tex...
[0] https://www.eia.gov/todayinenergy/detail.php?id=61364#:~:tex...
https://en.wikipedia.org/wiki/Proof_of_stake
The users of BTC also pay for that electricity consumption, and value is derived from having a ledger that is not controlled by any government. Building out clean energy sources is the real solution like nuclear, deep geothermal, solar, wind, etc.
Until we have >100% renewable all the time all the extra energy used by BTC only causes more CO2 positive sources to produce energy, if miners weren't using that electricity we'd be closer to full renewable energy today already.
The actual value of the existence for the sake of having an alternative 'currency' is also highly suspect to me as the deflationary endgame of BTC is very bad for people hwo are day to day spending most of their income. Deflation is great if you got in early and have large reserves you can sit on but for most people who would earn and spend in BTC mostly deflation is terrible. There's good reasons we moved away from the gold standard which BTC tries to recreate in digital form.