[Reason077]

Could the concept of proof-of-work be extended to prove that work was done cleanly, ie: using only renewable electricity rather than that produced from fossil fuels?

Perhaps renewable electricity producers could issue some sort of signed token which is then incorporated into the blockchain as proof that renewable electricity was purchased?

[runeks]

A digital signature can never prove anything about the world. And this doesn’t change by putting it in a blockchain.

[rcxdude]

You've now introduced a set of trusted entities validating something for consensus. Why bother with proof of work at that point? You only need it because you can't agree on a trusted subset of participants with the rest of the network.

[fredfoobar]

If we had a way to do this, why would we just limit it to crypto?