Hi Several methods can be used to deliver carbonates/silicates into the oceans 1) energetic surfs 2) spillways on hydroelectric dams 3) wave sinks/ocean pipes 4) tumble mills powered by renewable energy. 5) soil movements carrying rocks 6) seawater passing through coastal rock cliffs and 7) spreading minerals on marine plants such as mangroves, salt marshes and peatlands to enhance their growth and CO2 uptake.
More difficult is to create pathways (by boring, cutting etc) in peridotite rocks under oceans near ridges to increase their serpentinisation rates by permitting seawater to enter. Parminder Singh Independent Civil Engineer Kuala Lumpur, Malaysia On Sunday, August 9, 2015 at 12:50:52 AM UTC+8, Sabine Mathesius wrote: > > Hi, just a short clarification: > > The main point of our study is not that CDR is useless, but that it is > not effective enough to counteract business as usual CO2 emissions. Our > results stress, once again, that there is no alternative to immediate > emissions reduction - CDR can be deployed as a supplemental measure (and > maybe it should), but it would not be effective enough to reverse severe > changes caused by a delay in emissions reduction. > > On alkalinity addition: How likely is it that we would be able to do > this on a global scale? I could imagine that alkalinity addition might > be a way to protect a coral reef, being deployed locally, but globally? > I guess it would be much harder to do than atmospheric CDR and you would > have to be very careful how much alkalinity you add and how often, to > not further stress marine organisms? As far as I know, there are hardly > any studies on this? > > (By the way, our study is not only about ocean acidification, but also > about warming and oxygen depletion.) > > Best, > > Sabine > > > > On 08/08/15 12:50 am, Greg Rau wrote: > > If the goal is to restore ocean chemistry, it would indeed seem > inherently inefficient to do so via CO2 removal from air. Better to remove > excess CO2 from the ocean by chemical, geochemical, or biological means > (1), my favorite being alkalinity addition. > > Secondly, according to the IPCC (2) and now UNEP (3), RCP 2.6 scenarios > cannot be achieved without CDR - in the UNEP estimate, 300 Gts CO2 worth > by 2100. So while I don't think anyone is asking CDR to do all of the heavy > lifting, it would appear that at least some CDR is essential to achieve RCP > 2.6 and probably even less ambitious scenarios, depending on when/if we > ever get serious about emissions reduction. What then is the point of > dissing CDR if emissions reduction alone isn't going to save the ocean and > the planet either? > > > > 1) > http://link.springer.com/referenceworkentry/10.1007/978-94-007-5784-4_54 > > 2) > http://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter06_FINAL.pdf > > 3) http://www.unep.org/emissionsgapreport2014/ > > > > Greg > > > > -------------------------------------------- > > On Mon, 8/3/15, Andrew Lockley <[email protected] <javascript:>> > wrote: > > > > Subject: [geo] Long-term response of oceans to CO2 removal from the > atmosphere > > To: "geoengineering" <[email protected] <javascript:>> > > Date: Monday, August 3, 2015, 1:02 PM > > > > > http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2729.html > > > > Long-term response of oceans to CO2 removal from the > > atmosphere > > > > Sabine Mathesius,1, 2, > > Matthias Hofmann,1, > > Ken Caldeira3, > > & Hans Joachim Schellnhuber1, 4, > > > > Nature Climate Change (2015): > > doi:10.1038/nclimate2729 > > Published online 03 August 2015 > > > > Abstract > > > > Carbon dioxide removal (CDR) from the atmosphere has been > > proposed as > > a measure for mitigating global warming and ocean > > acidification. To > > assess the extent to which CDR might eliminate the > > long-term > > consequences of anthropogenic CO2 emissions in the marine > > environment, > > we simulate the effect of two massive CDR interventions with > > CO2 > > extraction rates of 5 GtC yr−1 and 25 GtC yr−1, > > respectively, while > > CO2 emissions follow the extended RCP8.5 pathway. We falsify > > two > > hypotheses: the first being that CDR can restore > > pre-industrial > > conditions in the ocean by reducing the atmospheric CO2 > > concentration > > back to its pre-industrial level, and the second being that > > high CO2 > > emissions rates (RCP8.5) followed by CDR have long-term > > oceanic > > consequences that are similar to those of low emissions > > rates > > (RCP2.6). Focusing on pH, temperature and dissolved oxygen, > > we find > > that even after several centuries of CDR deployment, past > > CO2 > > emissions would leave a substantial legacy in the marine > > environment. > > > > -- > > 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] > <javascript:>. > > To post to this group, send email to [email protected] > <javascript:>. > > Visit this group at > > http://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. 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]. 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