| >the high nutrient requirements needed to grow the biochar We seem to have forgotten that natural forests are incredibly productive, and don't need artificial fertilizer. So we have a proof-of-concept. How do they do it, and how can we emulate those processes? Spoiler alert: soil (along with the root action of plants) is essentially a flat biological nanomachine that breaks down solid rock and fixes nitrogen, manufacturing fertilizer in-situ. https://www.youtube.com/watch?v=x2H60ritjag Of course the logical way to do this is not to create some vast new land use category ("carbon forests" or similar), but to transition our largest current land use category -- agriculture -- from a carbon-releasing to a carbon-sequestering mode. It also helps to increase biomass per hectare in suburbs, by transitioning our current low-carbon-density lawns over to a biome that buffers substantial amounts of carbon. This is the fundamental insight behind Permaculture btw, which has been working on figuring out exactly what this looks like. It's a hard problem yes, but one with existential importance for humanity. >Biochar is basically coal, which could be burned and converted into CO2 again. ...so don't do that. :) It's it obvious that burning coal also needs to stop for effective climate mitigation? In this application, density matters. Biochar is extremely low density, and high in surface area, which makes it an ideal soil amendment which buffers rainwater and provides microbial habitat (not to mention raw carbon for building into soil biomass). By contrast actual coal is nearly worthless in this application. |