There's a nice handy fusion ball in the sky; but that isn't sufficient for CO2 removal, and if we do have a genuine incentive to remove it, I wouldn't want to bet that the incentives stop at any particular level and thus would give equal a priori credence to us ending up with too much or too little atmospheric CO2 with such technology.

This is exactly where I sit too.

We currently have financial incentives for producing CO2, which are proving almost impossible to reverse.

But let’s say we reverse them and create incentives for CO2 removal.

How are we going to change the incentive yet again, when it’s time to stop? By the time this happens, the CO2 removal lobby will be strong. Think about the jobs! The taxes! The communities!

It's hard to imagine how someone can look at the track record and then think "impossible! we will never figure it out!" when human history is basically a detailed record of us constantly "figuring things out" that previously seemed impossible. When something has yet to be figured out you are supposed to be baffled because the part where it all make sense doesn't come until after we figure it out. It doesn't guarantee we will figure out this or that specific challenge, but the well-established pattern gives ample reason to be optimistic.

I appreciate the case for optimism, and I agree that as a species we can be quite clever. We can also fail to address important issues with simple and obvious fixes in ways that boggle the mind (e.g. getting vaccinated or wearing masks during COVID). Whereas I might have once thought that our ingenuity would rule the day, it seems like a functional society requires more than just technology.

Getting vaccinated wasn’t an option during the halcyon days of Covid and like 95%+ of people I saw at public businesses in my red state were wearing masks (or at least attempting to) during that time period. But unfortunately people still needed to eat, work, purchase necessities, learn, get treated, etc. This all to say that I don’t really think your analogy really holds up in this context.

Survivorship bias. You're missing the big graveyard of civilizations that thought they could persist in the face of changing external circumstances but miscalculated. Many of those are buried in what are now deserts, created by their misguided land management.