According to the International Biochar Initiative
The biochar process is akin to a process utilized thousands of years ago in the Amazon Basin, where islands of rich, fertile soils called Terra Preta (“dark earth”) soils were created through a process similar to pyrolysis. The high fertility and carbon content of these soils – retained thousands of years later in the absence of additional inputs – is the subject of much research and agricultural interest, and underlies the formation of the International Biochar Initiative. Because the biochar is relatively inert, most of it remains in the soils for orders of magnitude longer than any other organic amendments. This means that biochar might be one of the only tools available in the near future that can actually remove carbon from the atmosphere in a virtually permanent form.
According to James Lovelock
It is too late for emissions reduction measures.
There is one way we could save ourselves and that is through the massive burial of charcoal. It would mean farmers turning all their agricultural waste – which contains carbon that the plants have spent the summer sequestering – into non-biodegradable charcoal, and burying it in the soil. Then you can start shifting really hefty quantities of carbon out of the system and pull the CO2 down quite fast. […]
The biosphere pumps out 550 gigatonnes of carbon yearly; we put in only 30 gigatonnes. Ninety-nine per cent of the carbon that is fixed by plants is released back into the atmosphere within a year or so by consumers like bacteria, nematodes and worms. What we can do is cheat those consumers by getting farmers to burn their crop waste at very low oxygen levels to turn it into charcoal, which the farmer then ploughs into the field. A little CO2 is released but the bulk of it gets converted to carbon. You get a few per cent of biofuel as a by-product of the combustion process, which the farmer can sell. This scheme would need no subsidy: the farmer would make a profit. This is the one thing we can do that will make a difference […]
According to Lisa Abend
Burn almost any kind of organic material — corn husks, hazelnut shells, bamboo and, yes, even chicken manure — in an oxygen-depleted process called pyrolysis, and you generate gases and heat that can be used as energy. What remains is a solid — biochar — that sequesters carbon, keeping CO2 out of the atmosphere. In principle, at least, you create energy in a way that is not just carbon neutral, but carbon negative.
And the benefits only begin there. When added to thin and acidic soil of the kind found in much of South America and Africa, char produces higher agricultural yields and lets farmers cut down on costly, petroleum-heavy fertilizers.