Bitcoin is not a protocol for honest people to reach spontaneous agreements. It uses algorithms to create consensuses, and audit might be powerless in this system.

My thinking behind this idea is that the sentiment of the author of this blog article is becoming more and more prevalent. Over the coming years pressure on bitcoin’s legitimacy will increase. To get ahead of this movement I propose to miners worldwide to create their own climate change accord and do this voluntarily. All it needs is a consensus to do so.

It's obviously good if worldwide miners all agree to protect the environment together. It's also right that many governments have paid a lot of attention to Bitcoin. However, Bitcoin is not to be strictly regulated by design.

A government strong enough might have the ability to control Bitcoin mining over the holders, but breaking decentralization in this way will kill Bitcoin in its fundamental, and it seems that no such government is going to do this for now, especially when the reason is "environmental problems", which is generally not in high priority. Beside this idea, maybe a BIP (Bitcoin Improvement Proposal) is the best way of achieving consensus, but I can't imagine such a proposal being approved based on its limited feasibility.

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.

Big miners would agree to audits of their resource consumption. There’s no other way.

Why not just use proof of stake and get it of all the useless nonce-calculations?

The nonce-calculations are what makes bitcoin an energy credit. It's why it's a valuable digital asset and commodity. If it cost ZERO dollars to create bitcoin it would just be fiat... useless inflation adding zero value to current shareholders.

Bitcoin are being traded by energy companies to subsidize their infrastructure and improve energy efficiency and capacity.

In some ways Bitcoin is a battery, because hydro dams don't idle generators as often they can sell their excess energy production and subsidize the dry season. Oil companies capture the natural gas flares and use it to power generators to mine bitcoin, etc. There really only needs to be one POW coin, and I think it's pretty obvious that Bitcoin is it.

because all that will do is just entrench the existing banking oligopoly.

proof of work is the only thing that maintains unforgeable costliness.

Every proof of stake system eventually centralized and failed.

What about proof-of-space?

And of course proof-of-work isn't necessarily immune to wealth centralization either.

PoW is far from immune to it as the Chinese have proven, as they hold roughly 49% of all BTC and 65% of all mining capacity on the planet.