It's mentioned in the whitepaper - https://ethereum.org/en/whitepaper/ https://ethereum.org/en/whitepaper/ > Note that in the future, it is likely that Ethereu

It's mentioned in the whitepaper - https://ethereum.org/en/whitepaper/ https://ethereum.org/en/whitepaper/ > Note that in the future, it is likely that Ethereum will switch to a proof-of-stake model for security, reducing the issuance requirement to somewhere between zero and 0.05X per year.