Large-scale tree planting can remove some CO2 from the atmosphere, but nowhere near as much as humans add by extracting and burning fossil fuels. See https://skepticalscience.com/1-trillion-trees-impact.html for a detailed assessment of what this looks like.
The IPCC has a chart showing what actions need to be taken over the next few years. Afforestation is one piece of many things, all of which we need to do.
I always thought we should plant hybrid poplar or maybe empress trees. Then coppice and turn the wood to biochar.
https://en.m.wikipedia.org/wiki/Coppicing
https://en.m.wikipedia.org/wiki/Biochar
You can do it multiple times and take cuttings to grow new trees. I dont know how much land a pig farm needs, but if it’s like chicken factories, they basically live in cramped spaces. So you can dump the biochar into the pig shit. Let it soak up the nutrients and then fertilize the stumps.
The biochar is now stable carbon that will be sequestered in the ground for hundreds of years