To turn matter into biochar requires heat input - so generally this means burning some sort of fuel - which releases CO2. Leaving the matter as it is, or buryin

To turn matter into biochar requires heat input - so generally this means burning some sort of fuel - which releases CO2. Leaving the matter as it is, or burying it does not require this fuel, hence the CO2 "savings" are even greater. To do all this to sequester carbon seems to be missing the point, and we'd all be better off by not burning anything in the first place. Well, organic matter normally releases carbon when it decays, so just leaving it as-is would be carbon neutral, liberating the carbon the plant originally drew from the air to grow. On the other hand, the pyrolysis process requires energy, yes, but releases very little carbon from the material being processed. The resulting carbon-rich biochar doesn't rot, so the carbon isn't released back into the atmosphere but remains in the soil, while new plants grow in place of the old ones, pulling more carbon from the air. The claim in the article, presumably, is that the carbon output associated with the energy to heat the biomass is less than the amount of inert carbon added to the soil, making the entire process effectively remove carbon from the atmosphere. Highly doubtful that the amount of carbon thus extracted would be significant, though. The soil improvement aspect is far more interesting to my mind, the carbon stuff is probably just a way to get more attention.