Don't forget: when a tree dies, the CO2 it absorbed is (indirectly) released back into the atmosphere. Unless you store the wood somewhere and keep it from being consumed by nature.
On an individual tree level, yes. But planting trees usually implies either:
- Designating new areas for entire forests to be grown (which all together is a store of CO2, even if individuals die and rot)
- Many individual trees in towns/cities, which would presumably be replanted if they die and so, again, in summation are a store of CO2.
Or just encourage everyone to have oak panelling, wood floors, and a huge excess of fine wooden furniture
