The problem with CO2 levels is that no one likes the solution not that we don't have one. I highly doubt adding AGI to the mix is going to magically make things better. If anything we'll just burn more CO2 providing all the compute resources it needs.
People want their suburban lifestyle with their red meat and their pick-up truck or SUV. They drive fuel inefficient vehicles long-distances to urban work environments and they seem to have very limited interest in changing that. People who like detached homes aren't suddenly affording the rare instances of that closer to their work. We burn lots of oil because we drive fuel inefficient vehicles long distances. This is a problem of changing human preferences which you just aren't going to solve with an AGI.
Assuming embedded AI in every piece of robotics - sometimes directly, sometimes connected to a central server (this is doable even today) - it'll revolutionize industries: human-less mining, processing, manufacturing, services, and transportation. These factories would eventually produce and install enough solar power or build sufficient nuclear plants and energy infrastructure, making energy clean and free.
With abundant electric cars (at this future point in time) and clean electricity powering heating, transportation, and manufacturing, some AIs could be repurposed for CO2 capture.
It sounds deceptively easy, but from an engineering standpoint, it likely holds up. With free energy and AGI handling labor and thinking, we can achieve what a civilization could do and more (cause no individual incentives come into play).
However, human factors could be a problem: protests (luddites), wireheading, misuse of AI, and AI-induced catastrophes (alignment).
Having more energy is intrinsically dangerous, though, because it's indiscriminate: more energy cannot enable bigger solutions without also enabling bigger problems. Energy is the limiting factor to how much damage we can do. If we have way more of it, all bets are off. For instance, the current issue may be that we are indirectly cooking the planet through CO2 emissions, so capturing that sounds like a good idea. But even with clean energy, there is a point where we would cook the planet directly via waste heat of AI and gizmos and factories and whatever unforeseen crap we'll conjure just because we can. And given our track record I'm far from confident that we wouldn't do precisely that.
This exactly. Every self replicating organism will eventually use all the energy available to it, there will never be an abundance. From the dawn of time, mankind has similarly used every bit of energy it generates. From the perspective of a subsistence farmer in the 1600s, if you told them how much energy would be available in 400s year they would think we surely must live in paradise with no labor. Here we are, still metaphorically tilling the land.
People want their suburban lifestyle with their red meat and their pick-up truck or SUV. They drive fuel inefficient vehicles long-distances to urban work environments and they seem to have very limited interest in changing that. People who like detached homes aren't suddenly affording the rare instances of that closer to their work. We burn lots of oil because we drive fuel inefficient vehicles long distances. This is a problem of changing human preferences which you just aren't going to solve with an AGI.