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Originally Posted by Turtle
I do not think it is practicle to attempt to ameleorate global warming by sequestering carbon in soils ala terra preta.
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Interesting comment... and I think the answer is that we really don't know yet. In an article on "Bio-char sequestration in terrestrial ecosystems – a review"
(www)css.cornell.edu/faculty/lehmann/publ/MitAdaptStratGlobChange%2011,%20403-427,%20Lehmann,%202006.pdf
Lehmann & others makes the case that bio-char production could be a significant tool to ameleorate global warming. While there's tons of articles (and 2 books) focusing mostly on the soil science of terra preta, there hasn't been that much research into what large-scale bio-char production would look like. Some of the current research underway is trying to gain a systems-level perspective of how this could fit into (or modify) existing agricultural/energy/etc systems.
Two other articles on "Bio-char and global carbon cycles" can be found here:
(www)css.cornell.edu/faculty/lehmann/biochar/Biochar_references.htm
There's a bit of uncertaintly on a global scale. For instance... charcoal has a very high energy content, and people in developing countries may be economically motivated to burn it for fuel instead of returning it to the soil. There's a lot of interesting questions, like how would we compare benefits/costs of charcoal as fuel vs. charcoal as soil amendment?
So it's really a question of how can we get this system to fit into larger existing techno-economic-social systems (also, how large could it become? what are the limits to spreading this technology). If you look through Eprida's presentations, you can see they're thinking about this in their slides on biorefineries. Biomass gasification is a bit of a swiss army knife for chemical production, and there may be opportunities for this technology to become economically sustainable by being a key process in numerous types of industries.
This systems level view is also important for projects such as Turtle's solar parabolic reflector. When the biomass is heated, it gives off syngas (CO, CO2, Methane). As some of you are probably aware, methane has 21x the global warming potential of CO2. So would this process be beneficial or harmful from a global warming perspective? Would some of the char absorb these gases and prevent their release into the atmosphere? I haven't run the numbers on the material balances, but my point is that before we can answer if bio-char is really the answer, we need to be aware of 2nd and 3rd order effects that may shape the success of the solutions we propose.
Cheers,
redgreenblue
Re: "Poems" for Terra Preta
semantics is not always just pedantic quibbling. ~ douglas r. hofstadter
Re: Terra Preta
I think using charcoal and other additives found in Amazonian dark soils to improve plant production is worthwhile. I do not think it is practicle to attempt to ameleorate global warming by sequestering carbon in soils ala terra preta. I think the best way to produce horticultural charcoal is by using a distributed system of solar trough ovens to produce charcoal from the excessive wood that centuries of fire suppression have allowed to build up in our forests.
Re: Terra Preta
Re: Terra Preta
