The basic point of this paper is not surprising but it is good to have it in the literature:
We find that solar shading approaches can redistribute productivity in the water column but do not change total production. Typically there is a sub-surface chlorophyll maximum because over most of the ocean organisms are more limited by nutrients than they are by light. The implicit question posed by the CBD is: if, in a high co2 world, solar geoengineering reduces the amount of temperature change by 90% or so, the amount of precipitation change by 70% or so, reduces sunlight by 2% or so (but increase diffuse radiation to 20% or so), will this overall protect or harm biodiversity? A subsidiary question is: if the answer to the above question is unknown, will relevant experimentation do more to help or harm prospects for marine biodiversity? On Tuesday, November 5, 2013, Michael Hayes wrote: > Dr. Seitz et. al., > > I do expect that the complexity of predicting the response of *free > swimming* photosynthetic organisms, propagated due to a large scale > mariculture installations' passive cooling of the surface water, is such > that their contribution to the overall maricultural operations' CO2 usage > would/should be considered incidental until field trials can provide > empirical data. > > The use of space based assets will be highly useful in the initial field > trials. The paper: Mapping size-speciļ¬c phytoplankton primary production > on a global scale <http://journalofmaps.com/student/10_01_Brewin.pdf> has > been my primary reference on the imaging side of this concept. Such imaging > may also prove useful in selecting installation locations. You referenced > Hardman Montford et al., should I seek out more recent works of his? > > Also, the architecture of large scale mariculture installations would be > web like structures most likely based upon hexagonal sections. This large > scale infrastructure would provide an excellent support/distribution means > for the use of Bright Water (BW). The use of BW, in itself, will have a > significant cooling effect on the surface water which will, in turn, affect > the nutricline depth. This would be especially true if the compressed air > was cooled/piped through deep water before release. This use of Ocean > Thermal Conversion (OTC) for direct surface cooling through BW seems to be > an efficient use of resources. > > Best, > > Michael > > On Saturday, November 2, 2013 9:38:13 AM UTC-7, Russell Seitz wrote: >> >> The response of free swimmng marine photosynthetic organisms to changes >> in the light fiels are complicated , because most utilize upwelling and >> scattered light as well as the direct rays of the sun in photosynthesis. >> The modeling results Hardman-Montford et al report recall simulations run >> at the ERES summer school two years ago. >> >> On Friday, November 1, 2013 12:28:17 PM UTC-4, andrewjlockley wrote: >>> >>> http://planetearth.nerc.ac.uk/news/story.aspx?id=1544&cookieConsent=A >>> >>> Link above is plain English. Abstract below >>> >>> Impacts of light shading and nutrient enrichment geo-engineering >>> approaches on the productivity of a stratified, oligotrophic ocean >>> ecosystem. >>> >>> Authors >>> >>> Hardman-Mountford NJ, et al. Show all >>> >>> Journal >>> >>> J R Soc Interface. 2013 Oct 16;10(89):20130701. doi: >>> 10.1098/rsif.2013.0701. Print 2013. >>> >>> Affiliation >>> >>> Plymouth Marine Laboratory, , Prospect Place, Plymouth PL1 3DH, UK. >>> >>> Abstract >>> >>> Geo-engineering proposals to mitigate global warming have focused either >>> on methods of carbon dioxide removal, particularly nutrient fertilization >>> of plant growth, or on cooling the Earth's surface by reducing incoming >>> solar radiation (shading). Marine phytoplankton contribute half the Earth's >>> biological carbon fixation and carbon export in the ocean is modulated by >>> the actions of microbes and grazing communities in recycling nutrients. >>> Both nutrients and light are essential for photosynthesis, so understanding >>> the relative influence of both these geo-engineering approaches on ocean >>> ecosystem production and processes is critical to the evaluation of their >>> effectiveness. In this paper, we investigate the relationship between light >>> and nutrient availability on productivity in a stratified, oligotrophic >>> subtropical ocean ecosystem using a one-dimensional water column model >>> coupled to a multi-plankton ecosystem model, with the goal of elucidating >>> potential impacts of these geo-engineering approaches on ecosystem >>> production. We find that solar shading approaches can redistribute >>> productivity in the water column but do not change total production. >>> Macronutrient enrichment is able to enhance the export of carbon, although >>> heterotrophic recycling reduces the efficiency of carbon export >>> substantially over time. Our results highlight the requirement for a fuller >>> consideration of marine ecosystem interactions and feedbacks, beyond simply >>> the stimulation of surface blooms, in the evaluation of putative >>> geo-engineering approaches. >>> >>> PMID >>> >>> 24132201 [PubMed - in process] >>> >> -- > 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:_e({}, > 'cvml', 'geoengineering%[email protected]');>. > To post to this group, send email to > [email protected]<javascript:_e({}, 'cvml', > '[email protected]');> > . > Visit this group at http://groups.google.com/group/geoengineering. > For more options, visit https://groups.google.com/groups/opt_out. > -- _______________ Ken Caldeira Carnegie Institution for Science Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 [email protected] http://dge.stanford.edu/labs/caldeiralab https://twitter.com/KenCaldeira -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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