Interesting idea, but how exactly would you validate the CO2 emissions? If somebody mines a block and claims it only consumed x of CO2, how do you know it is tr

Interesting idea, but how exactly would you validate the CO2 emissions? If somebody mines a block and claims it only consumed x of CO2, how do you know it is true? What seems possible is to check what miners mined a block, and externally verify their footprint. But I don't think there is a decentralized way to do it. An entity certifying "green miners" would be a centralized authority.