Folks, To point out the obvious, the results of Kwaitkowski et al may or may not scale to smaller deployments, and the effects of smaller deployments are likely to be regionally dependent.
I have been wanting to look at combined climate / energy implications of widespread deployment of OTEC facilities. If anyone knows of an exceptional candidate for a postdoctoral position in my group interested in pursuing these questions, please send them my way. (If someone is merely capable of conducting this investigation, I am not interested in hiring them.) Best, Ken *Ken Caldeira* *Carnegie Institution for Science* Dept of Global Ecology 260 Panama St Stanford CA 94305 USA +1 650 704 7212 http://CarnegieEnergyInnovation.org http://dge.stanford.edu/labs/caldeiralab <http://dge.stanford.edu/labs/caldeiralab> Assistant, with access to incoming emails: Jess Barker jbar...@carnegiescience.edu On Wed, Sep 13, 2017 at 3:34 AM, Chris Vivian <chris.vivi...@btinternet.com> wrote: > There are also the papers by Oschlies et al 2010 and Yool et al 2009 that > are quoted in the Kwiatowski et al 2015 paper. Copies of these papers > attached. > > Chris. > > On Tuesday, September 12, 2017 at 12:30:42 AM UTC+1, Andrew Lockley wrote: > >> https://www.sciencedaily.com/releases/2015/03/150319143337.htm >> >> Geoengineering proposal may backfire: Ocean pipes 'not cool,' would end >> up warming climateDate:March 19, 2015Source:Carnegie InstitutionSummary:There >> are a variety of proposals that involve using vertical ocean pipes to move >> seawater to the surface from the depths in order to reap different >> potential climate benefits. One idea involves using ocean pipes to >> facilitate direct physical cooling of the surface ocean by replacing warm >> surface ocean waters with colder, deeper waters. New research shows that >> these pipes could actually increase global warming quite drastically >> >> On 12 Sep 2017 00:21, "Robert Tulip" <rtuli...@yahoo.com.au> wrote: >> >>> Dear Andrew >>> Thank you very much for bringing this potential problem with Deep Ocean >>> Water as an algae nutrient source to attention. I would like to find out >>> more about the possible mechanism that you allude to. I looked again at >>> the 2005 IPCC paper on Ocean Storage <https://www.ipcc.ch/report/srccs/> led >>> by Professor Caldeira but did not find anything to support your reference. >>> If more recent work shows that raising DOW could cause warming I would like >>> to see it. I am following up other responses to my comments directly with >>> their authors. >>> Robert Tulip >>> >>> >>> ------------------------------ >>> *From:* Andrew Lockley <andrew....@gmail.com> >>> *To:* Robert Tulip <rtuli...@yahoo.com.au>; geoengineering < >>> geoengi...@googlegroups.com> >>> *Sent:* Friday, 8 September 2017, 10:47 >>> *Subject:* Re: [geo] Carbon budget/removal in NYTimes interactive >>> >>> Caldeira et al showed that moving water in this way causes warming. >>> >>> A >>> >>> On 8 Sep 2017 00:15, "'Robert Tulip' via geoengineering" < >>> geoengi...@googlegroups.com> wrote: >>> >>> Thanks Cristoph. >>> Deep Ocean Water, with volume about a billion cubic kilometres below the >>> thermocline, has about three ppm nitrate and phosphate, about 3000 cubic >>> kilometres of each, as I understand the numbers. Tidal pumping arrays along >>> the world's continental shelves could raise enough DOW to the surface, >>> mimicking natural algae blooms, to fuel controlled algae production at the >>> scale required for seven million square kilometres of factories. Piping >>> CO2 from power plants etc out to ocean algae farms could clean up all the >>> polluted air of the world. >>> Robert Tulip >>> >>> >>> ------------------------------ >>> *From:* Christoph Voelker <christop...@awi.de> >>> *To:* geoengi...@googlegroups. com >>> *Sent:* Friday, 8 September 2017, 8:43 >>> *Subject:* Re: [geo] Carbon budget/removal in NYTimes interactive >>> >>> I must admit that I am getting skeptical when I hear numbers in that >>> order of magnitude: >>> The total net primary production in the oceans presently is about 50 Gt >>> carbon, and 80% of that is converted back into inorganic carbon (and >>> nutrients) by heterotrophs before it gets a chance to sink out from the >>> sunlit upper layer of the ocean. The roughly 10 Gt carbon (some newer works >>> even estimate just 6 Gt carbon) that sink out have to be balanced by the >>> upward mixing of nutrients (and a little bit by atmospheric deposition of >>> bioavailable nitrogen and phosphorus) in the Redfield ratio of about >>> 106:16:1 of C:N:P. >>> So, if you want to remove 20 Gt carbon per year from the atmosphere, >>> you'd have to increase the nutrient supply to the total surface ocean by a >>> factor of three, maybe four. Maybe I am a bit too pessimistic here, because >>> there are species like Sargassum which have a higher C:N:P ratio than the >>> average phytoplankton, so you get somewhat more carbon per >>> nitrogen/phosphorus. But even if it is just doubling, I can't imagine that >>> you can sustain such a nutrient consumption by fertilizing from outside the >>> ocean (especially since phosphorus is scarce already now), you'd have to >>> tap into the inorganic nutrients stored in the deep ocean. How long can you >>> do that? >>> If we assume that we harvest all the 20 Gt carbon in algae from these >>> factories and do something durable with them (to minimize lossed through >>> heterotrophy and problems with creating oxygen minimum zones), we >>> effectively remove nitrogen/phosphorus from the ocean. How much is that per >>> year? >>> Let us for simplicity assume Redfield ratios, I grant errors by a factor >>> of two or so. 20 Gt carbon then corresponds to (20 >>> g/12(g/mol)/6.625(molC/molN))* 1.0e15 or about 2.5e14 mol nitrogen. The >>> ocean has a volume of 1.33e18 m^3, and the average concentration of >>> available nitrogen (mostly nitrate) is 30 micromol/L or mmol/m^3 >>> (calculated from the world ocean atlas), most of that is in the deep ocean. >>> This gives a total inventory of 4.0e16 mol nitrogen. 2.5e14 mol/year is >>> thus more than half of a percent of the total available nitrogen in the >>> world oceans, which means you could try that for about 150 years, then >>> everything is gone At that pace, nitrogen fixers are unlikely to resupply >>> the loss (nowaday, the residence time of nitrogen is roughly 5000 years), >>> and they can do that only for nitrogen, not for phosphorus anyway. Letting >>> technological problems aside (like: How do you move 2.5% of the total >>> nitrogen in the world oceans evry year up to an area 2% of the ocean >>> surface) I would call the whole idea - at least that the scale suggested - >>> a prime example of an unsustainable process. >>> Best regards, >>> Christoph Voelker >>> >>> On 07.09.17 23:37, 'Robert Tulip' via geoengineering wrote: >>> >>> The assumption behind the NYT interactive model >>> <https://www.nytimes.com/interactive/2017/08/29/opinion/climate-change-carbon-budget.html?action=click&pgtype=Homepage&clickSource=story-heading&module=opinion-c-col-right-region®ion=opinion-c-col-right-region&WT.nav=opinion-c-col-right-region> >>> that the upper bound for carbon removal is 12 GT CO2 by 2080 is too slow >>> and small. We should think five times as much and five times as fast. >>> Immediate aggressive investment to build industrial algae factories at >>> sea could remove twenty gigatons of carbon (50 GT CO2) from the air per >>> year by 2030, using 2% of the ocean surface, funded by use of the produced >>> algae. >>> That would stabilise the climate and enable no change in emission >>> trajectories, a policy result that would satisfy both the needs of the >>> climate and the traditional economy. >>> Robert Tulip >>> >>> >>> ------------------------------ >>> *From:* Eric Durbrow <dur...@gmail.com> >>> *To:* geoengineering <geoeng...@googlegroups. com> >>> *Sent:* Thursday, 7 September 2017, 3:13 >>> *Subject:* [geo] Carbon budget/removal in NYTimes interactive >>> >>> >>> FYI There is a slick interactive graphic at the NYTimes that lets people >>> see if they can meet the world’s carbon budget restriction but a >>> combination of reduced emissions AND achieving Carbon Removal. >>> >>> At >>> >>> https://www.nytimes.com/ interactive/2017/08/29/ >>> opinion/climate-change-carbon- budget.html?action=click& >>> pgtype=Homepage&clickSource= story-heading&module=opinion- >>> c-col-right-region®ion= opinion-c-col-right-region&WT. >>> nav=opinion-c-col-right-region >>> <https://www.nytimes.com/interactive/2017/08/29/opinion/climate-change-carbon-budget.html?action=click&pgtype=Homepage&clickSource=story-heading&module=opinion-c-col-right-region®ion=opinion-c-col-right-region&WT.nav=opinion-c-col-right-region> >>> >>> I failed after clicking on Reduce in all geographic areas and Achieve in >>> Carbon Removal. >>> >>> >>> >>> >>> -- >>> 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 geoengineerin...@ googlegroups.com. >>> To post to this group, send email to geoengi...@googlegroups. com. >>> Visit this group at https://groups.google.com/ group/geoengineering >>> <https://groups.google.com/group/geoengineering>. >>> For more options, visit https://groups.google.com/d/ optout >>> <https://groups.google.com/d/optout>. >>> >>> >>> -- >>> 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 geoengineerin...@ googlegroups.com. >>> To post to this group, send email to geoengi...@googlegroups. com. >>> Visit this group at https://groups.google.com/ group/geoengineering >>> <https://groups.google.com/group/geoengineering>. >>> For more options, visit https://groups.google.com/d/ optout >>> <https://groups.google.com/d/optout>. >>> >>> -- >>> Christoph Voelker >>> Alfred Wegener Institute for Polar and Marine Research >>> Am Handelshafen 12 >>> 27570 Bremerhaven, Germany >>> e: christop...@awi.de >>> t: +49 471 4831 1848 >>> >>> -- >>> 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 geoengineerin...@ googlegroups.com. >>> To post to this group, send email to geoengi...@googlegroups. com. >>> Visit this group at https://groups.google.com/ group/geoengineering >>> <https://groups.google.com/group/geoengineering>. >>> For more options, visit https://groups.google.com/d/ optout >>> <https://groups.google.com/d/optout>. >>> >>> >>> -- >>> 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 geoengineerin...@ googlegroups.com. >>> To post to this group, send email to geoengi...@googlegroups. com. >>> Visit this group at https://groups.google.com/ group/geoengineering >>> <https://groups.google.com/group/geoengineering>. >>> For more options, visit https://groups.google.com/d/ optout >>> <https://groups.google.com/d/optout>. >>> >>> >>> >>> -- > 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 https://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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