The contract should output a boolean value for a function isEthereumGreen()
This value is determined by comparing 2 values: costToCompensateUntilNow and sumCO2TokensBurned
sumCO2TokensBurned starts at 0 and can be increased by sending funds to the contract. This also mints N NFT's where N is calculated by dividing the amount send by a stable value (maybe using the MakerDAO oracle) or just accepting it in stable value like in DAI in the first place. This will also lead to the NFT being likely stable in price on secondary markets. This could be an interesting experiment on it's own. The funds are then converted to CO2 compensation tokens that are then burned. This might be batched to save on gas.
costToCompensateUntilNow is more complicated - it will either require an oracle or could be set by a DAO that is maybe consisting of people holding "I helped to make Etherum Green" NFTs or some independent group. It is calculated from 2 values costsUntilTheMerge and anualCosts multiplied by the years since the merge. To get a feel for costsUntilTheMerge you can read this document - but more research here is needed. But for the MVP some static values could be used that are upper bound estimates. But there should be the possibility to upgrade this to use different values or methods to get the values.
It would also be nice to see that people that helped making PoS possible (researchers, developers, testers, devops, auditors, stakers, ..) also get NFTs - but there the distribution is harder and maybe because of this outside the MVP. This also holds the opportunity to do an Airdrop to this group to get more traction and tick another buzzword for the bingo.
Also maybe interesting as a forcing function for some people could be a "leaderboard" like view in the "Who made Ethereum green" section of the dapp which shows the ENS name of the persons holding most "I helped making Ethereum Green" NFTs. So you can still have the bragging rights so many search my having NFTs - without all the speculation (as the Price for these NFTs is stable)
The dapp also should provide a simple view where it outputs either something positive if isEthereumGreen() like a nice solarpunk image featuring the Ethereum log alongside a text "Ethereum is green and net benefit for mother Earth" or something not so positive and scary looking like a big Elephant in an area where it could do damage if the value is false. This dapp you can point people to when discussing the environmental impact of Ethereum and instead you have to argue - they are either just convinced or can open an issue for the project which leads to maybe adjusting the values and them agreeing then.
The MVP should be on and only include L1 - but to be more efficient it could move to an L2. Also at some point it should also include L2's impact on consumption. Maybe it should be a standard across chains that they provide a IsThisProjectGreen contract. Maybe even a standard across projects/DAOs/Dapps so people can choose a path where they only use stuff that is positive for the planet on platforms that are also.
A nice time to launch this project could be the first block after "The Merge" - maybe just with the MVP at this point. The nice thing is this contract will not need to hold significant amounts of funds like some other contracts. So extensive security audits would not even be crucial - would still be nice to have more eyes on it - but maybe just for "I helped making Ethereum green" NFTs instead of having to pay the hefty prices for audits that you usually need for contracts that handle a lot of value.
But maybe it can also be launched before - would not make the MVP more complex - just adjusting anualCosts after the merge - but this value needs to be adjusted over time anyway so this should not be a problem. Seeing how much money is YOLOed for current NFTs and other things I could also imagine "Ethereum is now green" could be YOLOED by a small group easily and end the "Ethereum is bad for the planet" discussione even already before. So the Merge would just make it cheaper to refute this argument and be a net positive for the planet instead of a burden.
This idea was sparked by this tweet after this initiative which was relying on pure altruism did not really get the traction it needed. So maybe free riding this existing wave of NFTs could give it the traction it needs to return true for our core fun, help save some time in discussions, have a cleaner consciousness, and have a forcing function to make running Ethereum more energy efficient.
CC0