It's why I don't really like Jed's idea of burying trees. Clearing the land would release more methane than capturing and burying carbon.
I am not sure what you mean by that, but my plan does not involve "clearing" any land. Neither do any of the conventional carbon-capture by reforestation plans. In all of these plans, you begin by planting trees. The trees absorb and sequester carbon as they grow. You leave them alone. Most experts say they sequester less carbon as they approach a climax forest, as shown in this graph. Other experts say they continue to sequester about the same amount with annual leaf production. This is disputed, as I describe in the caption:
Caption: Tree growth patterns. Culmination in mean annual growth occurs after 40 to 50 years. Some experts think old growth forests continue to sequester carbon. “[W]hether carbon accumulation continues or peaks when net additional wood growth is minimal (in “old-growth” forests) is disputed.” Gorte, R.W., U.S. Tree Planting for Carbon Sequestation. 2009, U.S. Congress: Congressional Research Service.
Anyway, sometime after they reach climax they begin to die off naturally. Most trees live 30 to 50 years depending on the species. Oak trees live 300 years. You wouldn't plant all the same species, so the entire forest would not die of old age at one time. Over 30 to 300 years, they would all gradually die off.
Some trees die before the end of their lifespan from insects, drought, being hit by tornadoes or lightning, or being knocked over by other falling trees. The conventional plan is to leave them where they are and let the deadwood pile up, except as necessary to prevent excess fires and to keep the forests healthy. My plan diverges at this stage. I would have small cold fusion powered robots remove most of the deadwood, convert it to charcoal, and bury it. However, I would not "clear" any land. Just remove the dead trees. Most of them; not all. Some rotting deadwood is essential for forest health. The point of using small robots is that they can remove one fallen tree without disturbing the others around it, and without a large road. This would open a spot in the forest where another tree can grow, but it would not be anything like clear-cutting. In other words, it is a gradual replacement of the trees starting 30 years after reforestation, and continuing for 300 years, by which time all of original trees are buried underground in anerobic conditions, but the forest as a whole is as dense as it ever was.
Of course, some trees would be harvested normally for lumber or pulp. Some oak trees would be cut before 300 years elapses. I am not suggesting that every forest on earth has to be reserved for carbon sequestration only.
The other big difference between my plan and conventional ones is that I propose cold-fusion powered desalination to convert 3.5 million square kilometers of the Sahara and Gobi deserts back into forested land (about half of the desert land), which is what they were before people over-farmed them and made them into deserts. I would not eliminate the deserts completely, by any means.
