[asokoloski]

As far as I know, the most cost-effective method is very low tech--just find a good area and plant a variety of native trees.

[kaybe]

The biggest problem I see is that you now have to protect those trees for basically forever. Fires will only become more problematic, and the push for more usable land as well. Also, trees take decades to grow, which we don't have.

Better than nothing yes, but not enough.