After trying to reduce our emissions as much as possible, what kind of "best" choice to we have next?
Well charcoal is THE "captured carbon" which you wanted to get.
Rather than looking at this as if we are separate from the ecosystem we live in, and try to sequester carbon, I think the better approach is to develop deeper relationships with local ecosystem.
The problem isn’t carbon. The problem is that the carbon is not moving through the ecosystem. Probably one of the more practical things is to separate the local hydrological cycle from the local carbon cycle — that is, plant more stuff; feed onsite composting to the plants; make greater use of greywater, even blackwater; design dwellings and sites with sun and shade and more passive heating and cooling in mind.
On the trajectory we're currently on, a significant fraction of all species on earth could go extinct. There will be life, yes, but significantly less diverse life.
If we want to have better genetic diversity, it’s not going to come from reducing carbon emissions. It will be things like planting wildlife refuges in your front yard, at least poly-cropping not mono-cropping, letting landraces develop for local conditions instead of insisting on standardized produces. It’s participating within the ecology and not trying to take the entire yield and maximizing usefulness to humans. Reducing carbon emissions will not, by itself, get us there.
Desertification has to do with ecosystems degenerating. While there are regions that are desertifying because of changes in percipitation patterns, our industrial scale agriculture and feedlots are depleting the soil in a way that is leading to desertification, even without changes in climate patterns. We kill soil with fertilizers and pesticide. We got rid of beavers, and the way they reroute rivers and watershed to spread out water, making the land less resilient. We pipe water to grow things in areas we probably shouldn’t. The Great Dust Bowl was not a result of climate change.
Ocean acidification is a result of the ocean absorbing more atmospheric CO2 as a consequence of burning fossil fuels. It has affects on the health of marine ecosystems. It is not a consequence of climate change.
Soil is alive, dirt is dead. Healthy soils helps with water retention, and changes the local microclimates. So does designing canopy layers — agroforestry and perennial food forests.
Industrial scale monocropping is not adaptive, and kills off soil. It is fragile, and contributes little to regulating temperatures in the local microclimates.
There are solutions beyond simply looking at carbon emissions or industrial scale carbon sequestering.
That doesn't mean we shouldn't care about maintaining soil qualiy but your comment "heating irrelevant, just deepen your relationship with the environment" is vague and people basically hear "do nothing about the CO2/warming because it's fine, we just need more hippies loving the soil". That's probably not what you meant but it's how it sounds.
This is exactly what I am seeing with the messaging around “climate change” and “carbon emissions” and “carbon credits”. It allows people to continue with the way of life they are used to and feel good about doing their part.
When I say “get connected with the local ecosystem”, I am not espousing a hippie view.
Part of our modern way of life insulates us from really understanding at an instinctual and bodily level, what it means to be a part of an ecosystem or a community. I mean it literally: many people do not actually know what it is like to eat an apple off a tree, let alone a relationship with that particular tree, and all the birds, bees, worms, fungi, and microbes involved with that apple.
I don’t know how to say this any more literally and directly. Advocating for “doing something about CO2/warming” is so far away from getting your hands dirty, and knowing at a deep level, that this is our home, and we’re not the only ones living here, and that the land can very well provide healthy food, and our actions directly impacts the land around us.
Oh and as for warming — the Soviets were able to adapt warm-weather fruit bearing trees, and we can do the same. There are plenty of heat-hardy edible plants, if we are willing to go beyond the small handful of monocropped “food” we have standardized on. We can try using industrial scale solutions, but we are just kicking the can down the road. It is our way of seeing the world around us that lead us here.
What would you do with the CO2? Even if home CO2 capture was practical, sequestering CO2 gas is really hard.
A lot of the best chemicals for capturing carbon are very corrosive and dangerous to work with.
Your best bet would probably be making charcoal and burying it.