I've heard some talk about a CO2 Coin before (one where a coin is mined by carbon capture). I'm sure there are all sorts of reasons why it would not work, but it would be the only kind of crypto I'd ever be interested in owning.
I have no idea how to do this without opening yourself up to near-trivial cheating either, as the validation of work isn't intrinsically linked to the actual effort like current crypto coin systems rely on.
And if there's a centralized arbiter validating people's capture results, then you've just invented a centralized currency? Why have crypto at all? It sounds like carbon credits (with all it's failings) with extra steps.
> I have no idea how to do this without opening yourself up to near-trivial cheating either, as the validation of work isn't intrinsically linked to the actual effort like current crypto coin systems rely on.
This is known as the oracle problem and is actively being worked on.
Considering the absolutely huge CO2/environmental impact of BTC and other proof-of-work cryptos, talking about a CO2-coin for the purpose of CO2 sequestration sounds like quite a joke to me...
But the whole point is that it's not a proof-of-work crypto, or at least not a proof of useless mathematical number spinning. It's based entirely on carbon capture.
There are non-proof-of-work cryptos already out there.