Reforesting is a good idea, but it is necessary to know where and how
A little more than 200 million years ago, a forestation event almost led to the extinction of all life. Nature did not know a method to decompose lignin which is a major component of wood. This means that when trees died, they toppled over but could not rot in order to release their carbon back into the atmosphere. New trees sucked ever more carbon out of the air until carbon concentration was very low. So low that Earth flirted with the idea of mass suicide due to carbon starvation. Luckily, nature developed organisms that could digest lignin and CO2 concentration sprung up again. There was another brush with carbon suicide during the ice ages. Earth is dangerously low on carbon. A concentration wy above 1000ppm would be way more healthy. Industrial civilization and its carbon emissions gave Earth another lease of life.
Watts Up With That? 
