Hello Ken, I'm an advocate of direct air capture. I've followed this board for a while and hope this is an opportune moment to comment. My view is that large scale ocean based algae production can provide a geoengineering method that addresses both CO2 capture and solar radiation management, producing commercially valuable fuel, food, fertilizer and fabric in a method that is entirely ecologically sustainable. Algae production can combine the best features of Solar Radiation Management and CO2 Capture in a method that is funded by production of commercial commodities. Algae is the most efficient photosynthesis crop, and can be produced in controlled ocean environments, using energy from tide, wave, current, wind and sun to mimic the original process of deposition of fossil fuel, at very low operating and capital costs, if done on large enough scale.
Please see my description at http://rtulip.net/yahoo_site_admin/assets/docs/Algae_Biofuel_Feedstock_System_Provisional_Patent.285191915.pdf This is all public domain. I am more concerned about contributing to public goods than anything else. I just want to know if these ideas are feasible, so would welcome expert comment. My estimate is that controlled algae production on 0.1% of the world ocean could stabilise the global climate and deliver a path to steady reduction in CO2 concentration, through sustainable fuel, food, fabric and fertilizer production. Kind Regards Robert Tulip Program Manager Mining for Development Australian Agency for International Development www.ausaid.gov.au ________________________________ From: Ken Caldeira <[email protected]> To: [email protected] Cc: Geoengineering <[email protected]>; [email protected]; Howard Herzog <[email protected]>; John Schellnhuber <[email protected]> Sent: Friday, 23 March 2012 10:16 PM Subject: Re: [geo] Calgary meeting on Direct Air Capture - thoughts? "So what is the DAC business model, why is venture capital interested, and what does it have to do with stabilizing air CO2? " -- GH Rau Greg, I think you hit the nail on the head. If we think of direct air capture as negative emissions, then air capture is basically a more expensive way to reduce net emissions. So, the only plausible business model is serving activities where CO2 is needed where direct air capture may be able to provide the CO2 at lower cost (or at least more conveniently), i.e., the goal is to profit primarily by providing CO2 as a commodity. You mention enhanced oil recovery (EOR), which of course involves a net flux of carbon from geologic formations to the atmosphere. Another possible application might be military applications where you want to make jet fuels on a nuclear powered aircraft carrier using atmospheric CO2 and seawater. If the above framing is correct, then direct air capture is more about seeking profits from oil companies and the military-industrial complex than it is about reducing climate risk. As the IPCC concluded in its 2005 Special Report on Carbon Capture and Storage, there just aren't enough products that need CO2 as an input for provision of CO2 for industrial uses to be a significant contributor to climate risk reduction. If EOR is really a primary target application, then direct air capture is more about increasing atmospheric CO2 concentrations than it is about decreasing atmospheric CO2 concentrations; it is more about increasing climate risk than decreasing climate risk. It would be interesting to hear from the direct air capture companies whether they see themselves as being in the business of climate-risk reduction, and if they answer in the affirmative, it would be interesting hear their rationale. _______________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 [email protected] http://dge.stanford.edu/labs/caldeiralab @kencaldeira YouTube: Climate change and the transition from coal to low-carbon electricity Crop yields in a geoengineered climate On Fri, Mar 23, 2012 at 3:35 AM, RAU greg <[email protected]> wrote: Ron, >Thanks for asking: > >1) Wasn't invited to Calgary. > >2) As Socolow et al and more recently House et al. PNAS 108:20428–20433 have shown, if your game is removing CO2 from air, concentrating molecular CO2 from air is probably the last thing you want to do because of the prohibitive thermodynamics and hence cost. But what really irks me about the DAC crowd is they act as though they are inventing air capture, e.g., the Economist article's subtitle that gushes: >"The idea of pulling carbon dioxide out of the atmosphere is a beguiling one. Could it ever become real?" >or Marc Gunther's quote: >"Most scientists believe removing CO2 from the air is expensive and >impractical to do on a global scale." >Let me be the first to break the good news; air capture is occurring all >around us, to the tune of about 17 Gt CO2/yr. That's right, the equivalent of about 57% of anthro CO2 emissions is thankfully already being removed from air by natural process for free. I'd say that is a pretty good example of effective, low cost, global scale air capture, in contrast to the latest $1000/tonne CO2 figure of House et al. So, if one is interested in increasing air capture, the obvious places to start are figuring out how to 1) increase global photosynthesis (afforestation, ocean fetilization), 2) decrease respiration of biomass (biochar), or my favorite, 3) increasing mineral weathering rates. Then there are hybrids of 1 -3. Why start with a highly artificial and expensive process of concentrating molecular CO2 when nature provides much lower cost and less risky examples that are already in global scale operation? > >3) Haven't read Marc's ebook, but assume it's along the lines of the Economist article. Perhaps he'll send me a free, autographed copy > >4) See above. I've submitted a followup letter to PNAS, for what that's worth. > >5) Good point - why insist on concentrated, molecular CO2 as your end product? Nature doesn't. One has to conclude that EOR is their end game, in which case this generates a net air CO2 source rather than a sink: In standard CO2-EOR, 3 tonnes of CO2 are generated from product per tonne of CO2 injected. You can be sure that oil companies will want to increase (worsen) this 3/1 ratio if they are paying >$100/tonne CO2 injected. Traditional geologic sources of CO2 for EOR are less than 1/10th this cost. > > >So what is the DAC business model, why is venture capital interested, and what does it have to do with stabilizing air CO2? Any Calgarians care to fill us mortals in? > >Your humble messenger, >Greg > > > > > > > >________________________________ >From: "[email protected]" <[email protected]> >To: Geoengineering <[email protected]> >Sent: Thu, March 22, 2012 3:41:23 PM >Subject: [geo] Calgary meeting on Direct Air Capture - thoughts? > > > >List: > > 1. I thought this list had a very useful dialog a few months ago on the CDR >technology called Direct Air Capture (DAC - sometimes "Artificial Trees"). I >have just become aware of an invitation-only meeting on this topic - hosted by >the group "ISEEE" at the University of Calgary on March 6 and 7. A >preliminary agenda is available at: > http://www.iseee.ca/dacs/ > > 2. Two useful recent descriptions of the dialog are given at: > > http://www.economist.com/node/21550241 >and > >http://www.marcgunther.com/2012/03/11/direct-air-capture-of-co2-is-becoming-a-business-for-better-or-worse/ > > > 3. Marc Gunther also had an article on the major DAC companies just as the >meeting was starting at: > >http://chimalaya.org/2012/03/06/rethinking-carbon-dioxide-from-a-pollutant-to-an-asset/ > > 4. I gather from this material that Prof. Socolow was under considerable >pressure to lower his (and APS') decidedly negative projection on costs. I >wonder if any list member in attendance can comment on this controversy - that >was covered nicely on this list. > > 5. I also gather there was considerable unhappiness in the present >emphasis of all (?) of these DAC companies away from CDR - and instead on to >uses of the captured CO2 for enhanced oil/gas production and for combination >with H2 for appreciably lower carbon footprint fuel production. Any comments >on these aspects - or any other part of the meeting? > >Thanks in advance for any additional information. > >Ron > -- >You received this message because you are subscribed to the Google Groups >"geoengineering" group. >To post to this group, send email to [email protected]. >To unsubscribe from this group, send email to >[email protected]. >For more options, visit this group at >http://groups.google.com/group/geoengineering?hl=en. > >-- >You received this message because you are subscribed to the Google Groups >"geoengineering" group. >To post to this group, send email to [email protected]. >To unsubscribe from this group, send email to >[email protected]. >For more options, visit this group at >http://groups.google.com/group/geoengineering?hl=en. > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
