Hi Folks, Dr. Rau, thank you for the excellent papers. I recognize the paper "Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production" as the work/concept you introduced to this group a few years back and I'm glad to see it published. Solving for the energy to drive the system may lay within using passive downwelling devices, such as the Skaf downweller design Dr. Salter has offered above, coupled to 2 counter rotating subsurface turbines.
I have done some investigation into floating bag (bioreactor) algae cultivation, which Robert Tulip mentions, and it does offer a simple plantation size method for use of nutricline waters. However, it does require multi km long runs. Also, it is best situated in calm waters such as the central regions of the gyres. One approach to solving for all of the methods that have been brought to this thread (*without discounting issues/methodes not in this thread*) would be to create a large scale floating algae bioreactor cultivation complex within the central (calm) region of a gyre which terminates in the outer (wave) region of the gyre. There, passive Skaf/Salter Downwellers could downwell the algae biomass past subsurface turbines which would then power the full complex. You mentioned *"Actually, by strategically adding alkalinity to the naturally upwelling and degassing regions of the ocean (above), one would reduce the ocean's CO2 degassing and hence the air's CO2 burden without doing any air CO2 capture/removal."* Would that not also hold true if the upwelled water feeding the floating plantations were similarly treated? Here is a paper which may help tie this together: "Geoengineering impact of open ocean dissolution of olivine on atmospheric CO2, surface ocean pH and marine biology"<http://iopscience.iop.org/1748-9326/8/1/014009/article> Peter Köhler, Jesse F Abrams1, Christoph Völker, Judith Hauck and Dieter A Wolf-Gladrow Environmental Research Letters *"Ongoing global warming induced by anthropogenic emissions has opened the debate as to whether geoengineering is a 'quick fix' option. Here we analyse the intended and unintended effects of one specific geoengineering approach, which is enhanced weathering via the open ocean dissolution of the silicate-containing mineral olivine. This approach would not only reduce atmospheric CO2 and oppose surface ocean acidification, but would also impact on marine biology. If dissolved in the surface ocean, olivine sequesters 0.28 g carbon per g of olivine dissolved, similar to land-based enhanced weathering. Silicic acid input, a byproduct of the olivine dissolution, alters marine biology because silicate is in certain areas the limiting nutrient for diatoms. As a consequence, our model predicts a shift in phytoplankton species composition towards diatoms, altering the biological carbon pumps. Enhanced olivine dissolution, both on land and in the ocean, therefore needs to be considered as ocean fertilization. From dissolution kinetics we calculate that only olivine particles with a grain size of the order of 1 μm sink slowly enough to enable a nearly complete dissolution. The energy consumption for grinding to this small size might reduce the carbon sequestration efficiency by ~30%."* * * The energy needs related to fine grinding needs to be solved for. It may be possible to find an algae (Arthrospira maxima<http://microbewiki.kenyon.edu/index.php/Arthrospira_maxima>?) which could grow well within an olivine enriched/sub-thermocline water slurry within floating bioreactors. *In tubes, the olivine would not need to be as finely ground!* The slurry product could be used in a number of ways: 1) Food and fuel (per Capron). 2) Piping or shipping the slurry to enhance fisheries associated with natural upwelling (per Rau). 3) Direct sequestration on the floor (per Calvin). 4) Terrestrial crop fertilization (per The Irish;). Solving for energy is the fundamental issue. Gaining energy efficiency through combining some of the excellent ideas being proposed may prove useful. Also, I see nothing wrong with redundancy when it comes to geoengineering. Thanks to Dr. Schuiling for the short course on olivine. I recommend his '*Cookery book<https://docs.google.com/viewer?a=v&pid=gmail&attid=0.1&thid=13f94eb6bc421239&mt=application/vnd.openxmlformats-officedocument.wordprocessingml.document&url=https://mail.google.com/mail/u/0/?ui%3D2%26ik%3D05e7756a3b%26view%3Datt%26th%3D13f94eb6bc421239%26attid%3D0.1%26disp%3Dsafe%26zw&sig=AHIEtbSSaq9igKEvfD5OYr70tg4QwqkHvQ> *'. Also, a number of other concepts and technologies can be folded into this thought experiment and no offense is intended by omitting such. Best, Michael On Friday, June 28, 2013 5:00:57 PM UTC-7, andrewjlockley wrote: > > Poster's note: Some interesting stuff on ocean pipes, etc. Lots of > links in web version. > > http://ieet.org/index.php/IEET/more/brin20130628 > > The Science of Climate and Geo-engineering… and more > > David Brin > Ethical Technology > > Posted: Jun 28, 2013 > > On June 18 I joined a blue ribbon panel (via Google Hangout) on the > topic of Reinventing Climate Management: Staring Down the Possibility > of Geoengineering, led by scenario thinker Jamais Cascio, author of > the book Hacking the Earth: Understanding Geoengineering. He moderated > a terrific group of scientists and other innovators (plus me… for > comic relief I guess) wrestling with this issue, joined by visitors > from the web with questions and ideas. > > Managing the climate in the face of global warming is a wicked problem > that requires getting almost every independent nation to coordinate. > What would a system of global governance look like that's up to the > true challenges ahead? And how do we start thinking about whether we > need to take more desperate steps in the form of geoengineering? > > I came away from the discussion convinced, yet again, that some things > merit much closer examination and experimentation. Out of all of the > ideas that have been raised for either removing carbon from the > atmosphere or reducing the sunlight that feeds the greenhouse, only > one would attempt to emulate nature's own process for removing CO2, > the way by far the largest amount has already been removed -- through > chemical and biological sequestration in the open ocean. That proposal > is Ocean Fertilization. > > Yes, yes we have all read about silly, half-baked "experiments" in > which poorly instrumented boats dumped tons of iron dust into ocean > currents. These created plankton blooms, all right, but also > questionable after-effects. They did not get very good press. And > they poisoned the well - so to speak - for more intelligent proposals > that would more closely emulate what Nature, herself does. > > And if anyone gets tentative rights to "speak for Mother Nature" it > would be James Lovelock, author of the Gaia hypothesis. With Chris > Rapley, director of the Science Museum in London, Lovelock proposed > trying an option that would place vertical pipes some 200 meters long > in the sea to pump nutrient-rich water from depth to the surface, thus > enhancing the growth of algae in the upper ocean. The algae, which are > key in transporting carbon dioxide to the deep sea and producing > dimethyl sulphide involved in the formation of sunlight-reflecting > clouds, should help to prevent further warming. According to his note > in Nature: > > "Although fertilizing the ocean with iron as a way of stimulating > algal growth is being considered, the use of pipes to use the ocean’s > existing nutrients as fertilizer is certainly novel." > > Well… novel? Except that ocean bi-layer nutrient mixing was shown to > readers way back in my novel EARTH (1989). Our friend, The > Economist's Oliver Morton, wrote an extensive blog on the > Lovelock/Rapely proposal -- which may get funding from the Gates > Foundation for preliminary research. And Morton fairly describes some > of the critics, as well: > > “The concept is flawed,” says Scott Doney, a marine chemist at WHOI. > He says it neglects the fact that deeper waters with high nutrients > also generally contain a lot of dissolved inorganic carbon, including > dissolved CO2. Bringing these waters to the lower pressures of the > surface would result in the CO2 bubbling out into the air." > > Well, then shouldn't we look into it and find out? > > Might this concept be compatible with Nathan Myhrvold’s innovation… > pumping warm surface water below the thermocline? As reported by > Oliver Morton, the system would be something a bit like a floating > paddling pool with a long pipe dangling down from its centre. Because > there will be waves outside the pool but not inside, water will splash > in over its edge but not out, and so the water level inside the pool > is higher than the level outside the pool, providing the downward > force. A company called Atmocean has in fact built prototype systems > which aim to do it in almost exactly the opposite way to the Searete > patents, by using wave power to pump cool water up, but the effect > would be the same, spreading nutrients from below to where the > sunlight is… > > …exactly what happens in the world's greatest fisheries, off Chile, > the Grand Banks and Antarctica. Why do extra nutrients spur fecundity > and ocean health in those places, but not in "dying seas" that suffer > from eutrification (death by excess fertilizing runoff from > agriculture), like the Gulf of Mexico, the Mediterranean and > especially the Black Sea? Well… just look at them! The difference > should be obvious to the eye. The choked seas do not "drain well." > > Let's make a parallel. It is said that ninety percent of the oceans > are "desert" realms where very little lives, because of lack of > nutrients to feed a food chain… mostly the stuff that you find in > "dirt." Now turn back onto the continents. What do we sometimes do to > make deserts bloom? Onland we irrigated, bringing water to soil. At > sea the proposal is to bring "soil" to the water in a sense. (The > mouths of most river systems are also generally fecund.) > > Ah, you answer, but hasn't irrigation been a mixed blessing, and often > a downright curse? Yes! Our ancestors ruined the so-called "Fertile > Crescent" by pouring river water over fields, allowing salts and toxic > metals to accumulate until the land died. But this did not happen > everywhere. Many regions -- e.g. the Ganges valley and the Yangtze -- > have been heavily irrigated for thousands of years without suffering > desertification. Again, the reason should be eye-obvious: Those river > valleys had good drainage, allowing salts to be washed away by > monsoons. > > The Gulf Stream, the Antarctic Current, and the fisheries near Chile > are not enclosed seas -- they flow. So ocean fertilization > experiments should start where strong currents can disperse the > plankton blooms. So let's try some of the more natural-like layer > mixing or bottom stirring proposals. And let's see if we can make > another Grand Banks somewhere. > > == Another concept == > > A truly ambitious concept for ocean fertilization by layer mixing > would go beyond those mentioned above. It would use pipes more than > 1000 meters long and power them by planting the bottom end right atop > an oceanic hydrothermal (volcanic) vent! > > A thousand meters? Atop a volcanic vent? Well… I think we should try > some simpler mixing methods, first. > > == More factors == > > Again, Oliver Morton (in private correspondence) explained why the > first recourse in ocean fert has always been iron.: "Iron is > interesting because its a *micro*nutrient. That gives it great > stoichiometry -- you can see in the literature estimates of C:Fe > ratios of around 100,000:1, IIRC. That gets you a lot of C for a tonne > of Fe. As I understood it you were suggesting mobilising phosphorous > reserves in ocean sediments or deepwater. For phosphate fertilizaton > the ratio is 106:1 -- the ideal Redfield ratio of C to P in marine > biomass. The practical ratio, given losses, would almost certainly be > a lot less; for iron it is more than 10 times less. If that were true > for macronutrient fertilization, you'd get only a few tonnes of C > stored for every tonne of P mobilized. There have to be better ways of > getting rid of a tonne of C than that. You might do better -- 10 > tonnes C, maybe 30? But that still means a vast mass-moving operation > to work at the desired gigatonne C level, because you would have to > mobiliza a lot of tonnes of sediment or bottom water to deliver one > tonne of P. This is a very different and more extensive infrastructure > than needed for iron fertilization." (See Morton's survey of > geoengineering schemes in Nature: Climate Crunch: Great White Hope .) > > Wow. Okay. Look, I never doubted than iron fertilization was > efficient, compared to ocean bottom stirring, or bi-layer mixing. > What I maintain is that not enough attention has been paid to studying > the most effective parts of the ocean - e.g. the Grand Banks and Chile > and Antarctica -- to determine if they are also big net carbon sinks, > as well as fantastic fisheries. It does not seem to have occurred to > anyone that there might be other places on Earth that have almost the > right conditions and that might be tipped into similar fecundity with > just a little help. > > Instead, the reflex is to assume that all meddling is always bad, all > the time. Indeed, the metaphor I used was irrigation and that was the > very reflex. We all know what shortsighted irrigation did to the > Fertile Crescent... and that metaphor makes us ignore the lessons of > other watersheds that remained productive and healthy for 4000 years. > Again, this is the main difference between Chile, Labrador, > Antarctica... and the eutrophic dead zones in the Gulf of Mexico and > Mediterranean and Black Sea. > > To my knowledge, this consideration was not handled well in most of > the iron experiments. > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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