William,
A question: even if biomass is converted to CO2 in the deep ocean (>1000 m) would it not stay there? My understanding is that the deep ocean is not supersaturated, due to the high pressure; it is the reduction of pressure in a rising deep water column that causes degassing of CO2. Not sure this is correct, I would welcome your comments. Peter Flynn *From:* William Calvin [mailto:[email protected]] *Sent:* July-13-13 5:34 PM *To:* Peter Flynn *Cc:* [email protected]; [email protected]; geoengineering *Subject:* Re: [geo] My big-quick-secure CO2 cleanup proposal is still alive at the MIT geoengineering competition Circulation time for the water is about a thousand years but the radiocarbon age for DOC in the depths is more like 4,000 years. It's not a regional effect but widespread. I discussed it in the cleanup book: Estimates for the delay until the flushed surface water resurfaces range from 400 to 1,600 years. Excess carbon sunk to just below the winter thermocline is likely to resurface sooner. It may take a sinking depth of more than 1,000 m to achieve millennial-scale storage. In the cold depths, about half of the new dissolved organic carbon from the upper ocean is promptly converted into total CO2. But it has recently been shown that the rest has a 6,000 year residence time. Since the reason for this postponed oxidation into CO2 is not yet clear, one cannot say that half of the carbon debt, if sunk within twenty years, would also stay out of the atmospheric circulation for an extra 5,000 years. But it seems a good bet, one we should take. The major ref is McNichol, A and Aluwihare, L. I. “The Power of Radiocarbon in Biogeochemical Studies of the Marine Carbon Cycle: Insights from Studies of Dissolved and Particulate Organic Carbon (DOC and POC)" Luther III, G. W. and Boyle, E. A. Chemical Reviews (thematic issue on "Chemical Oceanography.) 107, 2007, pp.443-466. On Fri, Jul 12, 2013 at 9:00 PM, Peter Flynn <[email protected]> wrote: Mark, The residence time for exchange between the deep ocean and the shallow ocean is on the order of 600 to 1000 years. This is an average; there are ocean locations where the exchange is far slower (negligible downwelling and upwelling currents). Hence conversion of biomass to CO2 in the deep ocean would not liberate it to the atmosphere for a very long time, perhaps past the age of fossil fuels. I don’t know enough about the behavior of methane, i.e. whether it is soluble or would form gas bubbles. If it is soluble the same long storage would apply. Peter Flynn 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 *[email protected] *Sent:* July-12-13 9:40 PM *To:* [email protected]; [email protected] *Cc:* geoengineering *Subject:* RE: [geo] My big-quick-secure CO2 cleanup proposal is still alive at the MIT geoengineering competition Bill, At a quick glance: 1. I did not detect your nutrient cycling or nutrient mass balancing. There may be sufficient N, P, K, iron, etc. in deep water below the themocline. But what fraction are you extracting? 2. I am a wastewater engineer with some landfill and dairy waste experience. Do you know what fraction of the "sunk or pumped to bottom" carbon is available to anaerobic bacteria? Years ago, we used to think anaerobic bacteria required fresh water and mammal body temperatures to convert biomass to CH4 and CO2. Now we can buy anaerobic bacteria that produce at 5C for use in unheated temperate climate dairy digesters. The bacteria exist or evolve to work in all ocean conditions. The gas production at seafloor temperatures in seawater will be slower, but not that much. Perhaps 80% of volatile solids (aka ash-free biomass) hitting the deep seafloor should be converted to CH4 and CO2 within a decade, if not sooner. Mark E. Capron, PE Ventura, California www.PODenergy.org -------- Original Message -------- Subject: Re: [geo] My big-quick-secure CO2 cleanup proposal is still alive at the MIT geoengineering competition From: Andrew Lockley <[email protected]> Date: Fri, July 12, 2013 7:15 pm To: [email protected] Cc: geoengineering <[email protected]> I looked through it in detail earlier. Where's the evidence you can get anywhere near the numbers you need? A On Jul 13, 2013 4:13 AM, "William H. Calvin" <[email protected]> wrote: I seem to be one of the three finalists in this geoengineering competition, despite both judges remaining dubious and dismissive. You can judge for yourself, as it is all at http://climatecolab.org/web/guest/plans/-/plans/contestId/20/planId/1302501 My detailed response is in the Comment following the judges’ report. (Note that the revised proposal you see is not the original proposal the judges saw and from which I quoted in my reply Comment). The 2,000 word limit forced me to boil it down at lot but it has also become, I hope, a bit more understandable for those who haven't been following developments since 1983. A more complete proposal is in my short book, *The Great CO2 Cleanup*, at the Kindle store or the PDF at http://WilliamCalvin.org/bk16 <http://williamcalvin.org/bk16> . I have until Monday to make revisions to the proposal before final judging. Please email suggestions. If you wish to add public comments or “Supporter” endorsements, the Comments tab has a login/register link. I am encouraged to “use on-line social networks” to build support, something I am not good at doing. This competition is my best chance so far to get a wider audience to consider my reframing of the climate problem and its implications for the time scale of needed climate actions. Thanks to many of you for earlier comments, -Bill William H. Calvin, Ph.D. University of Washington, School of Medicine. -- 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. -- William H. Calvin [email protected] WilliamCalvin.org -- 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.
