[Terrapreta] maybe controversial

[Sean K. Barry]

Hi Ron,

RWL:
6.  If we on the Terra Preta list are arguing about whether the climate phenomenon is man-made, we have close to zero chance of doing anything about it.

Your 6. is one of the sanest comments I've seen posted on here in a long time!

Regards,

SKB
  ----- Original Message ----- 
  From: Ron Larson<mailto:rongretlarson at comcast.net> 
  To: Terra Preta<mailto:terrapreta at bioenergylists.org> ; lou gold<mailto:lou.gold at gmail.com> ; Sean K. Barry<mailto:sean.barry at juno.com> 
  Sent: Sunday, April 13, 2008 11:23 AM
  Subject: Re: [Terrapreta] maybe controversial


  Terra Preta Members

  This AM, Lou Gold put the emphasis back on Jim Hansen's hard science side of the climate debate, when Lou said of Hansen:

      "He also said, in "Target CO2: Where Should Humanity Aim?" ...

  'A reward system for improved agricultural and forestry practices that sequester carbon could remove the current CO2 overshoot. With simultaneous policies to reduce non-CO2 greenhouse gases, it appears still feasible to avert catastrophic climate change.'"

      RWL:  Several  points about this important quote:

  1.  This may be the first time that Hansen has talked at this length about negative carbon forestry/agriculture options.

  2.  The first sentence above could be interpreted to mean no-till, forest preservation, etc - not biochar.  That has been my interpretation of previous Hansen comments like this one.

  3.  However, this latest (still unpublished - with reference given again below) paper is different, because in a different paragraph Hansen says:
      "Carbon sequestration in soil also has significant potential. Biochar, produced in pyrolysis of residues from crops, forestry, and animal wastes, can be used to restore soil fertility while storing carbon for centuries to millennia (82). Biochar helps soil retain nutrients and fertilizers, reducing emissions of GHGs such as N2O (83). Replacing slash-and-burn agriculture with slash-and-char and use of agricultural and forestry wastes for biochar production could provide a CO2 drawdown of ~8 ppm in half a century (83).

  4.  The references (82) and (83) above are to papers by Prof. Johannes Lehmann - two of the best on biochar that we could ask for.  Terra Preta list readers should read these two if you have not:  
  82. J. Lehmann, Nature 447, 143 (2007).

  83. J. Lehmann, et al., Mitiga. Adap. Strat. Glob. Chan. 11, 403 (2006)

  5.  The second Hansen sentence that Lou has quoted above is important because Hansen is saying we have time.  But the sentence refers to "catastrophic".  I am less certain that we have the time (2007 arctic ice area was again a modern record minimum), but sure believe we have to try. 

  6.  If we on the Terra Preta list are arguing about whether the climate phenomenon is man-made, we have close to zero chance of doing anything about it.

  7.  The above is all on the article.  The Hansen supplementary material on p 21 says:

      "Waste-derived biochar application will be phased in linearly over the period 2010-2020, by which time it will reach a maximum uptake rate of 0.16 GtC/yr (83). Thus after 2030 there will be an annual uptake of 1.6 + 0.16 = 1.76 GtC per year, based on the two processes described."

  8.  I haven't had time to get into this - but we on "Terrapreta" can help Hansen by adding more substantiation on how much can be done.  Hansen is a cautious author - so I suspect the above may be on the low side.  He is not mentioning growth of bacteria and fungus , nor the added above-ground biomass that must occur.  Also no mention of agricultural NOx reduction. Anyone have alternative numbers?  And the costs to do this?

  9.  I hesitate to bring up a new topic - but yesterday's paper had a sizeable article on how climate mitigation procedures (thinking corn and soy and liquid fuels) were leading to rising food prices and therefore world hunger.  We on this list need to provide proof (more than statements) that biochar will sufficiently increase soil productivity that we can address hunger as well as climate issues.  There need not be the hard choice of this news article, but we need more proof if we are to help Hansen - who I now view as likely to be our most effective spokesperson.

  RWL end, but see Hansen web citation references below.

  This message is following Lou's message which began:
    ----- Original Message ----- 
    From: lou gold<mailto:lou.gold at gmail.com> 
    To: Sean K. Barry<mailto:sean.barry at juno.com> 
    Cc: Ron Larson<mailto:rongretlarson at comcast.net> ; Terra Preta<mailto:terrapreta at bioenergylists.org> 
    Sent: Sunday, April 13, 2008 4:43 AM
    Subject: Re: [Terrapreta] maybe controversial


    I first encountered James Hansen fifteen years ago. We were speaking at the same     
        <snip>

         
        On Sat, Apr 12, 2008 at 1:26 PM, Ron Larson <rongretlarson at comcast.net<mailto:rongretlarson at comcast.net>> wrote:

          Greg and list members:

              
          <snip>

              In this latest "Yankees" writing, there is reference to another unpublished article (submitted to Science) that is the best single piece I have seen on the evidence for man's involvement.  I hope you will read especially this second one, which can be found at  http://arxiv.org/abs/0804.1126<http://arxiv.org/abs/0804.1126> 

          and the Supporting Material is at: 
          http://arxiv.org/abs/0804.1135<http://arxiv.org/abs/0804.1135> 

              <snip to end>


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