Overall for sure a good building block, but the issue with planting trees is this:
a) the necessary area to do it, if I am not mistaken we would need roughly the area of the USA or so
b) time
c) the forests must be allowed to grow, and left in peace
d) carbon in the atmosphere is already at such a high level, that plants already become less efficient in filtering it out than they used before
e) the impact of massively new forests is disputed.
In my opinion mankind will get in this century so desperate that we are going to really start looking at geoengineering, and put some ideas into action, like artificially emulating the impact the outburst of the Pinatubo had on the global climate for a long period of years.
Which is a lot cheaper than sucking plants, but also quite a bad idea due to the unknown outcome of such methods.