Re cold water pumped up then sinking: Might this help solve the problem of sinking organic carbon before it decomposes?
William H. Calvin [email protected] ________________________________ From: [email protected] <[email protected]> on behalf of Stephen Salter <[email protected]> Sent: Friday, September 15, 2017 9:18:30 AM To: [email protected] Subject: Re: [geo] Carbon budget/removal in NYTimes interactive Hi All A problem with pumping cold water up to the surface is that it will sink quite fast. Kaye and Laby give the density of 3.5% salinity water at 5 C as 1027.68 and at 25 C as 1023.34 kg/m3 We can work out the drag on various shapes of object and find the velocity which gives a drag force equal to the buoyancy deficit. For a 1 metre diameter sphere I make this 0.65 metres a second and a more likely shape would be a torpedo nose down with less drag and an even higher velocity. It seems better to pump warm surface water down, let it mix with cold water and then rise to a level set by the density of the mixture which we can control. This allows the pipe to have a small positive pressure so it can be made of thin plastic with no hoop rigidity. If the method ends up warming because of reduced cloud cover why not use an amount which will offset the increase of cloud cover due to the expected increased evaporation? We need lots of different tools in harmony. Stephen Emeritus Professor of Engineering Design. School of Engineering, University of Edinburgh, Mayfield Road, Edinburgh EH9 3DW, Scotland [email protected]<mailto:[email protected]>, Tel +44 (0)131 650 5704, Cell 07795 203 195, WWW.homepages.ed.ac.uk/shs<http://WWW.homepages.ed.ac.uk/shs>, YouTube Jamie Taylor Power for Change On 15/09/2017 16:03, Ken Caldeira wrote: 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 Assistant, with access to incoming emails: Jess Barker [email protected]<mailto:[email protected]> On Wed, Sep 13, 2017 at 3:34 AM, Chris Vivian <[email protected]<mailto:[email protected]>> 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 climate Date: March 19, 2015 Source: Carnegie Institution Summary: 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" <[email protected]> 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 [X] 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 <[email protected]> To: Robert Tulip <[email protected]>; geoengineering <[email protected]> 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" <[email protected]> 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 <[email protected]> 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 [X] [X] [X] 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 <[email protected]> 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 [X][X][X]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 [X] [X] [X] https://groups.google.com/ group/geoengineering<https://groups.google.com/group/geoengineering>. For more options, visit [X] [X] [X] 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 [X] [X] https://groups.google.com/ group/geoengineering<https://groups.google.com/group/geoengineering>. For more options, visit [X] [X] 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: [email protected] 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 [X] [X] https://groups.google.com/ group/geoengineering<https://groups.google.com/group/geoengineering>. For more options, visit [X] [X] 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. 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