[Terrapreta] Catalyst: Carbon Bigfoot

[Sean K. Barry]

Hi Chuck,

Check you math?

Global average CO2 concentrations have risen to 380 ppm now, in 2007, versus 250 ppm in 1850.  The ecology of the Earth, by itself, cycles 120 billion tons of carbon (~440 giga-tons of CO2) into and out of the atmosphere every year.  Humans add 6 billion tons of carbon to the atmosphere every year, primarily from burning fossil fuels.

It is not the goal of GHG reductions to bring the ~3 trillion (3000 billion) tons of CO2 down to zero tons of CO2 immediately.  Rather, to reduce CO2 concentrations to pre-industrial levels would only require going from ~3 trillion tons of CO2 down to (250/380) * 3 = ~2 trillion tons of CO2.  Hence, only removing ~1 trillion tons of CO2, which is equivalent to (12/(12+16+16))*1E9 = 272 billion tons of carbon.

Since charcoal is 90-95% pure carbon, then 272 billion tons of carbon is approximately 300 billion tons of charcoal.  Since you claim that there are 5 billion hectares of arable land, then it seems to me that the desired reduction in atmospheric carbon could be achieved by putting 10 tons/hectare of 5 billion hectares of land, for 6 consecutive years.  Additionally, the same could be accomplished by putting 50 tons of charcoal per hectare onto only 300 million hectares of land for 20 years.

The entire land surface of the Earth is ~510 million square km (or ~51 billion hectares).  If some of the land other than the 10% arable land were used as a place to sequester charcoal carbon into soil, then we might be able to do the necessary sequestration sooner and EXPAND the amount of arable land at the same time (i.e. making Terra Preta soil from degraded soil, reclaiming it, and making deserts bloom, if you will).

If you (or anyone else on this list) find any error in my calculations here, then please let me know and we can discuss it.  Please bear in mind that I am accepting your numbers, Chuck, of 3000 billion tons of CO2 in the atmosphere now and 5 billion hectares of arable land.

Regards,

Sean K. Barry
Principal Engineer/Owner
Troposphere Energy, LLC
11170 142nd St. N.
Stillwater, MN 55082-4797
(651)-285-0904 (Work/Cell)
(651)-351-0711 (Home/Fax)
sean.barry at juno.com<mailto:sean.barry at juno.com>
  ----- Original Message ----- 
  From: Chuck Yokota<mailto:cyokota at innovativeenergyinc.com> 
  To: Terrapreta<mailto:terrapreta at bioenergylists.org> 
  Sent: Monday, December 10, 2007 1:28 PM
  Subject: Re: [Terrapreta] Catalyst: Carbon Bigfoot



  The Earth's atmosphere holds roughly 800 billion tons of carbon in 3000
  billion tons of carbon dioxide.  Field experiments mentioned on the list
  use 5 to 10 tons of char per hectare.  There are 5 billion hectares of
  agricultural land in the world.  If every farmer applied 10 tons of char
  per hectare, that would take 50 billion tons out of the carbon cycle.
  This would still leave carbon dioxide levels far above pre-industrial
  levels.  Farmers would need to apply more than 50 tons per acre to bring
  carbon dioxide levels back to pre-industrial levels.  I would expect
  that the agricultural value of more char would hit an economic limit of
  diminishing returns long before it reached that point.  We are not in
  danger of depleting the Earth's atmosphere of carbon dioxide.

  Kevin wrote:

  Dear Lou

  lou gold wrote:
  > Hi Duane,
  >
  > del...
  > The only thing that I question is your assertion that we must continue

  > to generate CO2 in order to feed the plants. It seems to me that there

  > is a huge reservoir already available. Do you know of any studies or 
  > models that might suggest when CO2 will "peak" and require replacement

  > inputs, perhaps from fossil fuels?
  The Greenhouse Industry has done alot of work, and research papers, on 
  the benefits and economics of CO2 to greenhouse atmospheres in teh 
  winter, when greenhouse ventilation is low. The plant canopy strips the 
  CO2 from teh closed atmosphere very quickly. Commonly propane or natural

  gas is burned, with products of combustion vented into teh growing 
  space, to enrich CO2 to enhance plant growth.

  A Google search for "greenhouse CO2 Enrichment" gives 21 hits; with no 
  quotes, you get about 340,000 hits.

  Best wishes,

  Kevin


  _______________________________________________
  Terrapreta mailing list
  Terrapreta at bioenergylists.org<mailto:Terrapreta at bioenergylists.org>
  http://tech.groups.yahoo.com/group/biochar/<http://tech.groups.yahoo.com/group/biochar/>
  http://terrapreta.bioenergylists.org<http://terrapreta.bioenergylists.org/>
  http://info.bioenergylists.org<http://info.bioenergylists.org/>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/terrapreta_bioenergylists.org/attachments/20071210/89edd335/attachment.html