| Planting trees isn't a viable (complete) solution though for various reasons. - Healthy forest has 40-60 trees per acre This means you need 31,250,000~ square miles which is 15.87% of the Earth's landmass. - You need adequate rainfall where you plant the trees - For the healthiest trees, and best carbon sequestration, you also need to 'seed' the mycorrhizal networks that work in cooperation with tree roots. - You'd have to pick appropriate species for appropriate areas - Mature trees, the vast majority of the time, sequester far more than younger trees - There is considerable variation in the amount of carbon various trees can sequester in a given time Some land that actually used to sustain decent tree populations, is now nearly barren. A good example of this is Iceland. When the first settlers reached Iceland in the latter half of the 9th century, forests covered between 25 and 40% of the landscape (nearly 10-16k square miles), it is now around 0.5% with active efforts to reintroduce trees with the reintroduction going very slow. This year they are attempting to plant around 4 million trees but a fraction of those will likely survive. |