It's actually a clever plan. They will destroy ecosystems on the way so its not _perfect_, but it's feasible and will likely work if they fuccessfully find the right kind of tree to start the forest. Greenland is doing it too[1], with a lot of setbacks, but they are starting to recover (albeit slowly)

[1]https://www.nytimes.com/interactive/2017/10/20/climate/icela...