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Published online 1 May 2008 | Nature | doi:10.1038/news.2008.791

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Charcoal's green image blackened

The idea of using charcoal as a carbon sink may be over-optimistic.

Rachel Courtland

Unpalatable to bacteria and largely stable, charcoal has been touted as a powerful way to trap carbon. But it might actually prompt soil to release carbon at higher rates, new research indicates.

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  • Hi, Charcoal as a Surface activity should be considered in the degree of its activation. Heated charcoal is more effective than the latent form, basic thermodynamics. Regards Dr. Terence Hale

    • 03 May, 2008
    • Posted by: Terence Hale

  • Hi, this is a very interesting piece of work, using a simple approach (often the best!). It just shows how much more research is needed on the topic of biochar C sequestration as a mitigation strategy. Let us assume that the same relative SOC loss can be found in mieral soils where biochar (or charcoal or agrichar, whatever we call it) has been added and ploughed in - most certainly, this will promote the soil fertility and crop yield at these sites (one of the striking features of biochar + N-fertilizer addition). Then a potential soil C loss will depend on the amount and quality of new fresh plant litter input - possibly the wheel of soil C and N transformations will simply turn faster in the presence of biochar in soils, driven by a more active and larger soil microbial community. Given that the C input increases on a more fertile biochar site, the overall SOC loss of that site may not decline at all. This may explain why the Terra Praeta soils in the Amazon basin are not depleted in SOC, and are still highly fertile after thousands of years. Regards, Dr. Claudia Kammann

    • 07 May, 2008
    • Posted by: Claudia Kammann