If local soils are dry, there's no need to convert it to biochar. My understanding is that this proposal relates to relatively arid areas, so nearby soils may be dry, particularly at depth.
Large logs, dried naturally before burial in dry soils, should last of the order of centuries. I've got concerns over this proposal, in that large scale afforestation has direct and indirect albedo impact, and affects weather systems. These effects need to be accounted for. I've seen research on these issues presented by a lady at the Oxford Martin School, but can't locate the paper, unfortunately. A On Aug 1, 2013 9:32 AM, "Schuiling, R.D. (Olaf)" <r.d.schuil...@uu.nl> wrote: > In essence I agree with Fred’s logic, although you might create a longer > sequestration by converting the Iatropha biomass into biochar and bury it > in the soil. Given the conditions that are described, this may lead to a > better water retention in the soil as well, Olaf Schuiling**** > > ** ** > > *From:* geoengineering@googlegroups.com [mailto: > geoengineering@googlegroups.com] *On Behalf Of *Fred Zimmerman > *Sent:* woensdag 31 juli 2013 21:58 > *To:* Andrew Lockley; geoengineering > *Subject:* Re: [geo] ESD - Carbon farming in hot, dry coastal areas: an > option for climate change mitigation**** > > ** ** > > I am trying to understand the CDR logic with regard to biomass > "sequestration." Let's say we run these jatorpha carbon farms for 40 > years. The resulting "woody biomass" will release its CO2 back into the > atmosphere after X years or a big fire, whichever occurs first, in a dry > coastal area... Essentially, we would be paying 42-63 EUR/tonne CO2 to push > the CO2 X years into the future, where X is not that big a number (compared > to oceanic or geologic sequestration). I don't see our descendants > thanking us profusely for this particular effort, am I missing something?* > *** > > > **** > > ** ** > > ---**** > > Fred Zimmerman**** > > Geoengineering IT! **** > > Bringing together the worlds of geoengineering and information technology* > *** > > GE NewsFilter: http://geoengineeringIT.net:8080 **** > > ** ** > > On Wed, Jul 31, 2013 at 3:04 PM, Andrew Lockley <andrew.lock...@gmail.com> > wrote:**** > > http://www.earth-syst-dynam.net/4/237/2013/esd-4-237-2013.html**** > > Carbon farming in hot, dry coastal areas: an option for climate change > mitigation**** > > K. Beckermet et al**** > > Abstract**** > > We present a comprehensive, interdisciplinary project which demonstrates > that large-scale plantations of Jatropha curcas – if established in hot, > dry coastal areas around the world – could capture 17–25 t of carbon > dioxide per hectare per year from the atmosphere (over a 20 yr period). > Based on recent farming results it is confirmed that the Jatropha > curcas plant is well adapted to harsh environments and is capable of > growing alone or in combination with other tree and shrub species with > minimal irrigation in hot deserts where rain occurs only sporadically. Our > investigations indicate that there is sufficient unused and marginal land > for the widespread cultivation of Jatropha curcas to have a significant > impact on atmospheric CO2 levels at least for several decades. In a system > in which desalinated seawater is used for irrigation and for delivery of > mineral nutrients, the sequestration costs were estimated to range from > 42–63 EUR per tonne CO2. This result makes carbon farming a technology that > is competitive with carbon capture and storage (CCS). In addition, > high-resolution simulations using an advanced land-surface–atmosphere model > indicate that a 10 000 km2 plantation could produce a reduction in mean > surface temperature and an onset or increase in rain and dew fall at a > regional level. In such areas, plant growth and CO2 storage could continue > until permanent woodland or forest had been established. In other areas, > salinization of the soil may limit plant growth to 2–3 decades whereupon > irrigation could be ceased and the captured carbon stored as woody biomass. > **** > > Citation: **** > > Becker, K., Wulfmeyer, V., Berger, T., Gebel, J., and Münch, W.: Carbon > farming in hot, dry coastal areas: an option for climate change mitigation, > Earth Syst. Dynam., 4, 237-251, doi:10.5194/esd-4-237-2013, 2013.**** > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to geoengineering+unsubscr...@googlegroups.com. > To post to this group, send email to geoengineering@googlegroups.com. > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/groups/opt_out. > > **** > > ** ** > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to geoengineering+unsubscr...@googlegroups.com. > To post to this group, send email to geoengineering@googlegroups.com. > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/groups/opt_out. > > **** > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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