Right, but the process of going from no trees to enough trees that can change climate enough to sustain themselves is very hard, and one bad year in the process

Right, but the process of going from no trees to enough trees that can change climate enough to sustain themselves is very hard, and one bad year in the process can reset many year worth of progress. The linked article made me think that perhaps it is possible to create a new species of a tree that would bootstrap this change naturally. With new gene editing methods, it should be possible to combine features of different plants to do this.