> Can you elaborate on multiagenct cooperation?

In short what Paris Agreement intends and what it fails to achieve. It assumes signatories will be voluntarily reducing their carbon emissions without binding enforcement, and they don't.

For a while let's assume that energy production is the only activity that causes carbon emission. Compared to staying at status quo, reducing carbon emissions is at least expensive for its infrastructure transition costs, but can also be more expensive for its operating costs if the country was particularly rich in non-green energy resources. This means, making a transition while others are not is particularly disadvantageous to that state's economy; they will be producing everything for more expensive while buying cheaply produced non-green imports from non-abiding countries. This is even worse if we consider that no single country's carbon neutrality means much for meeting global warming targets.

This means defecting is very profitable for any given country, which creates a game theoretic equilibrium at no one doing any decarbonization. Transitioning to the other equilibrium (where everyone is handicapped equally with green production) requires every agent to be ensured that other agents are not defecting in a lockstep fashion, and current policy tools cannot achieve that (at least yet).

It seems like you’re correctly identifying the tragedy of the commons nature of environmentalism, but then advocating that we ruin the environment because if we don’t someone else will, which is to say the only sure-fire way to lose. Maybe I’m misreading—it’s late. Hopefully you will correct my error.

I am not advocating that, in fact I am with you in how bad it is, but I am also telling what the incentive structure looks like and what would it take to move it to the other equilibrium point. There are many and different types of agents in this game and appeals to morality or apocalypticism just don't work on them. There needs to be a concrete, depolarizing, global leadership that coordinates this transition, to make sure parties don't defect despite cheating being very profitable, and they also believe that this will be the case with others.

Paris agreement was an attempt at this but also demonstrated that we still couldn't muster the political will to do anything sufficiently concrete. Unlike nuclear weapons, which has much fewer agents to coordinate with and a more immediately imaginable impact, climate change proves to be difficult problem regarding the nature of coordination it requires and ease of popularizing the policies around it. We need tools to match that difficulty.

Thanks for clarifying. I don’t see why the Paris Agreement is a useful analog for a carbon tax. A carbon tax doesn’t depend on the good faith of partner countries, but the border adjustment itself incentivizes other countries to reduce their emissions (they want to trade with us). The more wealthy countries who implement a carbon tax with border adjustment, the stronger this incentive mechanism becomes. There is a political problem in getting a larger block of wealthy countries on board, but it’s not unrealistic to think of Europe and North America forming that initial block, and surely there’s enough wealth in those markets that it would incentivize other countries to get on board.

In whatever case, I can’t imagine an environmental solution that won’t have the same (or worse) political problems. As far as I can tell, border adjuster carbon tax most neatly and efficiently aligns incentives.