Thanks, Ron - That's all quite informative and a welcome enhancement to
whatever else I've seen on the subject. My comments were intended to be
about soils' capacities separate from what contributions of biochar could
accomplish. I think the FAO figure of 20 PcG also wasn't taking biochar
into account.
It was interesting to see in the Japanese paper that char powder had
beneficial results in terms of plant growth even in rice paddies and for
mature pine trees. There's a lot of work being done on reducing methane
outputs from rice paddies (a major source); presumably, char could
contribute to that.
The mention of fungal symbionts also was in reference to such fungi being a
major factor in carbon cycling globally, rather than being about
interactions with biochar. To the extent that species of fungus are
introduced to soils as new plants arrive, that alters soils' sequestration
capacities.
In North America, where virtually all earthworms have been brought in by
humans from elsewhere, their invasive proclivities have been vastly
expanded by the dumping of excess fish-bait all over the country, with the
result that the numbers of worms per volumes of soil in some areas are
absolutely phenomenal, forest ecosystems are being transformed (because
leaf litter completely disappears, and the organisms, including plants,
which depend on that material don't survive), albedo of soils is altered,
and soil biota are affected by worms' relentless consumption. Also, the
worms presumably have their own metabolic GHG impacts, whatever those are.
Such considerations are relevant to schemes for improving biosequestration
in soils.
Aryt
On Jan 21, 2016 6:09 PM, "Ronal W. Larson" <[email protected]>
wrote:
> List with ccs
>
> Inserted response comments below.
>
> On Jan 20, 2016, at 7:38 PM, aryt alasti <[email protected]> wrote:
>
> I do very much so believe that there is huge potential for enhancing
> soil-sequestration capacities globally. Prof. Smith indicates that
> ultimately capacity is maxed out, so that measure to increase would be
> transitional in nature.
>
> *[RWL1: We can probably all agree that there is an upper limit to how
> much biochar can be placed in soil (and the char-caused above ground
> carbon out-year increments as well). But some of us think that there is
> plenty of room to increase today’s (in-soil total) 2000-2500 Gt C by the
> 15-20% we need to remove from the atmosphere. *
> * And there is a guaranteed long-term slow release of that biochar-carbon
> - so I can agree with your term “transitional”. But I don’t believe either
> the total C or the loss rate are serious limitations for CDR via biochar -
> nor that Prof. Smith has indicated s**o.*
>
> Allan Savory believes otherwise, but I don’t support his master plan as
> being feasible or ethical, which is a long story.
>
> *[RWL2: This observation relates to my previous point #3 (not repeated
> here) - related to Prof. Smith’s most recent article on SCS - Soil Carbon
> Sequestration. I’m not sure what Aryt’s concern is with Mr. Savory’s
> Holistic Management (HM) advocacy calling for more cattle. My concern is
> with enteric methane release - but that is too big a topic to enter here.*
>
> There are a lot of potential factors which don't receive attention when
> the topic of soil carbon is covered. For instance, invasive or migrating
> plants bring new fungal symbionts to soil, which process carbon.
>
> *[RWL3: The problem of new fungal symbionts is something I haven’t heard
> anything about re biochar. But invasive species are a global problem - and
> biochar production is one way to justify the expense of clearing them out
> (as in several past bills in the US Congress and being practiced already in
> at least Nepal).*
>
> And check this out:
>
> http:// <http://www.serc.si.edu/labs/molecular_ecology/earthworms.aspx>
> www.serc.si.edu
> <http://www.serc.si.edu/labs/molecular_ecology/earthworms.aspx>
> /labs/molecular_ecology/
> <http://www.serc.si.edu/labs/molecular_ecology/earthworms.aspx>
> earthworms.aspx
> <http://www.serc.si.edu/labs/molecular_ecology/earthworms.aspx>
>
> *RWL4: There are plenty of articles on the
> earthworm-biochar relationship; both favorable and unfavorable. The
> pre-planning should include this issue. Biochar can have a wide range of
> pH and water-holding characteristics - that can impact how worms respond.
> An issue - but not a show stopper I believe.*
>
> The Food and Agriculture Organization claims that:
>
> *Soils can sequester around 20 **PgC** (**petagrams** of carbon) in 25
> years*, more than 10 percent of the greenhouse gas emissions caused by
> humans.
> Aryt
>
>
> *[RWL5: I found this last statement to be an exact quote (#2)
> at http://www.fao.org/zhc/detail-events/en/c/345543/
> <http://www.fao.org/zhc/detail-events/en/c/345543/> . The FAO value of
> 10% at first sounded low to me - but in fact may be more aggressive than
> most - when tied to the term “25 years”. To show this - consider wedges
> as developed by Pacala and Socolow
>
> https://www.princeton.edu/mae/people/faculty/socolow/Science-2004-SW-1100103-PAPER-AND-SOM.pdf
> <https://www.princeton.edu/mae/people/faculty/socolow/Science-2004-SW-1100103-PAPER-AND-SOM.pdf>*
>
> * Assuming a continuation for the 50 year period recommended by Pacala and
> Socolow and one wedge sequestering 25 Gt C, my computations show that this
> FAO soil contribution would be 3.2 wedges with an annual rate in year 50 of
> 3.2 Gt C/yr by which time 80 Gt C would have been removed. If the majority
> of this soil sequestration is via biochar, all these numerical values can
> be augmented due to out-year benefits. I doubt that the FAO considered
> ocean biomass, so the number could be well on its way to handling all our
> heritage carbon - not just 20 or 80 Gt C. The growth problem of course is
> much more complicated than the linearity expressed by a wedge - but not
> impossible.*
>
> * In following this “Socolow” part of this thread, I saw much of CDR
> value at and near this site
> (http://cmi.princeton.edu/wedges/forestation.php
> <http://cmi.princeton.edu/wedges/forestation.php>) also associated with
> Prof. Socolow. Of his four types of wedges, only the biomass versions are
> shown as (CDR-type) sinks.*
>
> * [RWL6: I am not claiming that the FAO was thinking in wedge terms; I
> could find nothing on how the FAO International-Year team came to the above
> 20 Pg C in 25 years. There is plenty on biochar at FAO sites, but their
> very recent handling of the year 2015 as an International Soil Year
> certainly was not tied in well with COP21 and wedges. *
> * The acronym “zhc” at this above FAO site (which handled the
> international soil year) stands for “Zero Hunger Challenge”. The claim is
> made there that we need about $160 per poor person per year to alleviate
> hunger. I believe a small portion of that toward biochar would go a long
> way on the hunger side - and would then (at no extra cost) do a lot for
> sequestration. *
> * Here is an example of one of the 600+ biochar cites I today found in the
> FAO library:*
> *http://www.fao.org/fileadmin/templates/rap/files/meetings/2011/110602_potential.pdf
> <http://www.fao.org/fileadmin/templates/rap/files/meetings/2011/110602_potential.pdf>
> .
> It is not widely known that the Japanese were the world leaders in biochar
> until the last decade or so.*
> * So congratulations to FAO for the good soil-CDR work they do. And
> thanks to Aryt for his second follow-up comments.*
>
> *Ron*
>
> ps The following kept by Aryt from my message of 18 Jan- with an
> exchange under this thread that started on 11 Jan, with a response by Prof.
> Smith the next day - along with his attachment of his very recent
> SCS-biochar paper.
>
>
> Aryt and list: one added cc; also changing thread title back to the one
> where Prof. Smith has already contributed.
>
> 1. Thanks for your lead yesterday to an important related biomass-soil
> paper (chapter title: “Soaking up the Carbon”) by Professor Smith
> (courtesy cc). I
>
> <snip>
>
> Again - thanks for the additional Smith paper.
>
> Ron
>
>
>
> On Jan 17, 2016, at 1:23 AM, aryt alasti <[email protected]> wrote:
>
> Here's an interesting summarization on the subject by Smith, from a few
> years ago:
>
>
> https://scholar.google.com/citations?view_op=view_citation&hl=en&user=7P9W6pYAAAAJ&cstart=360&citation_for_view=7P9W6pYAAAAJ:N5tVd3kTz84C
>
> Aryt
> On Jan 16, 2016 5:36 PM, "Ronal W. Larson" <[email protected]>
> wrote:
>
>> Andrew and list:
>>
>
> <snip - rest not needed >
>
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