Plants don't absorb CO2 at all actually. Sure they do photosynthesis get the C out of the CO2 and use that to grow. The O2 gets released, the CO2 is no more and everyone is happy right? Well not really. While this is true in the short term, it isn't true in the long term. In the long term, the plant dies and all of that C gets combined with O2 again and releases CO2. How long this takes depends on the plant of course, some only live a year or shorter, others go for decades. And trees for example can live for hundreds of years, that is very much the exception to the rule. Even within trees only a fraction of them get that old, with most dying in a couple of decades.
The core concept is carbon cycles: https://en.wikipedia.org/wiki/Carbon_cycle
The fast (sometimes called short) carbon cycle is what plants usually do, they grow and they absorb, they die and they release. This cycle works on the order of years or decades. This is super duper overly simplified, but you get the idea.
The slow (sometimes called long) carbon cycle is where carbon is captured in geological processes. Carbon gets absorbed from the atmosphere and is captured for millions of years. This cycle is why our planet isn't a super hot house like Venus, as the carbon is incorporated in the mantle and core. This cycle works on the order of millions of years.
What humans have been doing for the past 150 years is taking carbon from the slow carbon cycle and putting that carbon into the atmosphere. We've mined all sorts of carbon rich materials for our industrial revolution. We've taken a huge shortcut, exploding our population and technology with essentially stolen energy.
Extracting carbon from the slow cycle and injecting it into the fast cycle isn't the same as putting it back into the slow cycle. It's a short term hack that might seem to work, but in reality only slows down the process a tiny bit. We have no idea how to put carbon back into the slow cycle and from what we do know, it takes probably at least 5 times as much energy as we stole by releasing the energy. So we don't just need to pay back what we stole, we also need to pay interest and a fine. The debt humanity has been accumulating has gotten bigger and bigger and the time left to pay has gotten shorter and shorter.
Sure in theory if we substantially and over a long period of time increase the amount of plant mass on the planet, we can store some of the carbon in that surplus. However in practice this has often lead to so called Green Washing. Companies buy so called carbon credits to offset the carbon they release. The idea is that the money they pay is used to increase the plant mass and thus store some of that carbon. This however turned out to be mostly a scam. A big issue was the amount of plant mass increase didn't match the carbon released, so it was a nett release and not neutral or capture. Another issue was credits were being sold for plant mass that already existed and wouldn't be increased at all. Often they promised not to decrease it, but this promise was either not backed up by anything, or the plant mass was already protected and wasn't going to decrease anyways. Another huge issue was credits being sold multiple times for the same plantmass, so in fact just a straight up scam. And like I said, unless the plantmass would be increased for at least hundreds of years in a sustainable way it's just a small bandaid. Most companies have stopped greenwashing these days as people have learnt it is a total scam and stricter laws have been applied to prevent these bogus claims.
Another big issue is the amount we release each second is so huge, we can't fight that with an increase in plantmass. So whilst I support the increase of plantmass and the protection of existing nature (for more reasons than just the carbon), it isn't a solution and I hate that greed fucked up this entire concept. Another L for capitalism I guess.
Now not all is lost, there is still time to pay of the debt. But we need to reduce the amount we are actively stealing and start thinking about paying some of it back. As for how to do this? I have no idea, but I'm sure it can be done. We need to move away from capitalism, number must go up and consumerism. We must start building products we use for life and not so cheap they fall apart or are even planned to not last. We need to reduce, re-use and recycle. We need our food to be more sustainable (and might even make it more healthy while we are at it). We need right to repair, with manufacturers being legally forced to provide documentation, spare parts and repairable designs. And all firmware and accompanying software needs to be open sourced.
But in a world where technology moves so fast and everything is designed around consumerism, I doubt we will be able to do it. Especially the last few years we have accelerated in the wrong direction. But we shouldn't give up hope, we can still do it.
And don't believe in that bullshit argument that we will create an AI that solves global warming for us. We already know exactly how to stop global warming, we just lack the motivation to do so. AI can only accelerate global warming, not stop it or reverse it.
