Fred,
I think forest sequestration has less certainty than deep ocean disposal over a 500 year framework. However, cost needs to be factored in as well: if it is an affordable choice, a low cost per ton might offset the lower certainty. Further, suppose future climate makes the forest unsustainable. As long as the wood doesn’t rot, the carbon remains sequestered. If the lack of sustainability is due to low rainfall, the trees might remain. Otherwise, they might be harvested for biomass fuel or sunk in the ocean. Hence I end up in the same place: I would not write this off until I saw a further honing of costs and technological soundness. Best, Peter *From:* Fred Zimmerman [mailto:[email protected]] *Sent:* July-31-13 5:35 PM *To:* Peter Flynn; geoengineering *Subject:* Re: [geo] ESD - Carbon farming in hot, dry coastal areas: an option for climate change mitigation Do forests sequester carbon with the same physical security and long time span as the deep ocean or geologic structures? My impression from what I've read is that forests can come and go on centennial scales. --- 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 4:10 PM, Peter Flynn <[email protected]> wrote: Fred, Once a forest is mature it is in equilibrium, and no incremental carbon is sequestered. However, the growth to maturity takes carbon out of the atmosphere. Hence this is a one time sequestration effort that lasts as long as the forest. If a forest fire came, and the forest were subsequently regrown, one would still have removed the amount of carbon contained in the forest. (I’m ignoring any secondary effect of char). Hence I think this alternative can be compared to any other one time means of sequestering carbon. Peter Peter Flynn, P. Eng., Ph. D. Emeritus Professor and Poole Chair in Management for Engineers Department of Mechanical Engineering University of Alberta [email protected] cell: 928 451 4455 *From:* [email protected] [mailto: [email protected]] *On Behalf Of *Fred Zimmerman *Sent:* July-31-13 1:58 PM *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 <[email protected]> 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 [email protected]. To post to this group, send email to [email protected]. 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 [email protected]. To post to this group, send email to [email protected]. 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
