I meant the net ocean CO2 sink is about 7 GT CO2/yr (or 2 GT C/yr). - Greg
>________________________________ > From: "Rau, Greg" <[email protected]> >To: "[email protected]" <[email protected]>; >"[email protected]" <[email protected]> >Cc: "[email protected]" <[email protected]> >Sent: Sunday, June 30, 2013 9:02 AM >Subject: RE: [geo] Re: (Ocean pipes) The Science of Climate and >Geo-engineering… and more David Brin Ethical Technology > > > > >Michael, >You say, "No bubbling of CO2 has ever been reported in field trials." Trust >me, ocean upwelling is a major source of atmospheric CO2, degassing >300 GT >CO2/yr. Fig 2.2.9 in the attached is what I often use to illustrate the very >elevated pCO2 in upwelled surface waters relative to the atmosphere and the >rapid degassing to air that therefore takes place (sans bubbles). Fortunately >for us, such leakage globally is slightly more than countered by CO2 >ingassing, making the ocean a small net CO2 sink of about 2 GT/yr. > > >If you are going to artificially, vertically stir the ocean your are going to >increase this degassing, so you had better hope that the nutrients also >upwelled to the surface indeed stimulate enough photosynthesis to counter that >CO2 loss to the atmosphere. That won't happen if nutrients are vertically >subducted out of the photic zone before algae consume them, if the biomass >formed is not rapidly sunk into the deep ocean and hopefully buried in >sediments, if the algae are grazed by zooplankton and the carbon respired back >to CO2 in surface waters, etc. All of these processes are very tricky to >accurately quantify and integrate over 4 dimensions (e.g., see attached), >meaning that whether or not you have created a net air CO2 sink is likely to >be highly uncertain. The required field experiments and sink verification >would keep oceanographers employed for decades. > > >I think a more obvious and certain enterprise in our narrowing window of >opportunity would be to study enhanced air CO2 removal via ocean chemistry >modification and not ask altered ocean biology (or physics) to do the heavy >lifting. 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, as discussed here: >http://www.pnas.org/content/early/2013/05/30/1222358110.full.pdf > > >-Greg > > >From: [email protected] [[email protected]] on >behalf of Michael Hayes [[email protected]] >Sent: Saturday, June 29, 2013 12:26 PM >To: [email protected] >Subject: [geo] Re: (Ocean pipes) The Science of Climate and Geo-engineering… >and more David Brin Ethical Technology > > >David, > > >Here are a few links I pulled up from past discussions and posts on this >overall subject. > >Deepwelling: >https://groups.google.com/d/msg/geoengineering/eValFNH8IQY/lJNWKARxs88J > > >Further, the cultivation of algae, in conjunction with tubes, provides a >significant counter to DIC. No bubbling of CO2 has ever been reported in field >trials. I found the following statement does not reflect the views of Gao >et.al.. > > >“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." > > > >"Use of Macroalgae for marine Biomass Production and CO2 remediation" Gao et >al. J.A.P. 1994 >Please see page 52, second column, 1st paragraph. >mel.xmu.edu.cn/upload_paper/201155112811-wse806.pdf > > >On the statement: "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." > > >There is the issue of incomplete sequestration of the biomass in such "strong >currents". Would it not be better to pump the biomass down (plow it under) >into a deep valley, which has no current, where the undecomposed biomass could >be sequestered for geological times? > > >On the statement: "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." > > >The global commercial fishing industry has, at this time, covered every >hectare within that category. Those areas that come even close to being viable >for being "tipped" are highly valued and protected as nurseries. > > >I believe the best place for ocean pipes/algaeculture/sequestration is the >North Pacific Gyre. Hopefully, we would be able to sequester at least some of >the trash in the gyre along with mountains of seaweed. > > >Best, > > >Michael > > > > > -- >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]. >Visit this group at http://groups.google.com/group/geoengineering. >For more options, visit https://groups.google.com/groups/opt_out. > > > -- >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]. >Visit this group at http://groups.google.com/group/geoengineering. >For more options, visit https://groups.google.com/groups/opt_out. > > > > > -- 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]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
