Hi! Not a climatologist, but plant scientist/ecologist. Can you elaborate more about why tree planting isn’t enough? A mature forest is carbon neutral, yes. Young saplings will fix atmospheric carbon as they grow, though. I have no idea how many you’d have to plant to make a dent in the runaway atmospheric carbon levels - is that the issue? It would also have to be a careful species choice depending on location, with (I’d imagine) a preference for longer-lived species with persistent wood.

I’m not saying afforestation is the solution, but surely it’s one facet of a comprehensive solution?