Consider the scale of what you're describing now: cutting down and burying all trees on earth every 30 years. We could certainly _burn_ all of them every 30 y

Consider the scale of what you're describing now: cutting down and burying all trees on earth every 30 years. We could certainly _burn_ all of them every 30 years, but that wouldn't help. The figure you need is the marginal capture after the emissions from the process. Wikipedia says our current emissions from fossil fules and cement production is estimated at 10GtC (not absurd compared to your numbers, since you count only crude oil). So restating, if somehow without adding any new carbon buried _all_ the vegetation on earth every 30 years, we'd remove 21 GtC per year or a net reduction of 11. To get back to pre-industrial levels it would still take 34 years even ignoring the >1000 GtC currently in the ocean surface that would come out of solution and fight the reduction. (I have no idea how to setup the diff eqs for solving for the ocean contributions...) The fact that an emission free removal and replacement of all vegetation of earth would still take a long time is basically my point around "planting trees" not being a sufficient plan. :) Not that planting trees is bad, but solving this is going to take some mixture of reduction and magic (presumably both the political and technological kind).