Russell, surely most iron loss from hulls isn't in the iron depleted waters?
A On 13 Feb 2014 12:12, "Russell Seitz" <russellse...@gmail.com> wrote: > This seems plausible , but a comperable if not greater environmental > impact may arise from another emission from the same vessels- while the > deliberate release of 100 tonnes of iron off the Haida coast by the > Planktos organization has been widely condemned , nobody seems to notice > the far larger tonnage of iron streaming into the ocean as the steel > hulls of millions of tonnes of shipping reacy with sea water and their own > acidic exhaust. > > I noted ths de facto ocean fertilization in a note in* Science* online > in 2008: - > > http://www.sciencemag.org/content/318/5855/1368.full/reply#sci_el_10731<http://www.sciencemag.org/content/318/5855/1368.full/reply#sci_el_10731> > Russell Seitz > > On Wednesday, February 12, 2014 6:14:13 PM UTC-5, Greg Rau wrote: >> >> Thanks, Oscar. However, this problem would seem to pale in comparison >> to CO2 acidification with an ocean input of about 8 GT (vs the stated MTs >> of SOX and NOx). Also, probably dwarfed by SOx and NOx from land based >> generation. Speaking of seawater scrubbing, this is also commonly done at >> power plants (esp Asia) - good for air but very efficiently acidifies the >> ocean. Solution - place limestone downstream of the gas/seawater >> contacting. You could do the same for ships if they were wiling to >> sacrifice some cargo tonnage for limestone. >> Greg >> ------------------------------ >> *From:* geoengi...@googlegroups.com [geoengi...@googlegroups.com] on >> behalf of Oscar Escobar [oscar200...@gmail.com] >> *Sent:* Wednesday, February 12, 2014 1:00 PM >> *To:* geoengi...@googlegroups.com >> *Subject:* [geo] Shipping emissions can lead to high local ocean >> acidification >> >> Strong acids formed from shipping emissions can produce seasonal 'hot >> spots' of >> ocean acidification, a recent study finds. These hot spots, in ocean >> areas close to >> busy shipping lanes, could have negative effects on local marine ecology >> and >> commercially farmed seafood species. >> >> Shipping emissions can lead to high local >> ocean acidification >> >> Oceans have become more acidic since pre-industrial times. The average >> global ocean pH - >> which decreases with increasing acidity - has dropped by 0.1 because the >> seas have >> absorbed 30-40% of manmade CO2. However, it is not only CO2 that can >> acidify oceans. >> Shipping emissions, a significant source of atmospheric pollution, >> annually release around >> 9.5 million metric tons of sulphur and 16.2 million metric tons of nitric >> oxides. >> >> When dissolved in seawater, these pollutants are converted into the >> strong sulphuric and >> nitric acids, adding to ocean acidification. Increasing acidity poses a >> threat to marine >> ecosystems, harming species such as coral and algae, as well as >> commercial aquaculture >> species, such as shellfish. >> >> The researchers used state of the art computer modelling techniques and >> datasets to create >> a high resolution simulation of global shipping emissions' effects on >> ocean acidity. The >> simulation calculated the acidifying impacts of shipping sulphur and >> nitric oxide emissions on >> a month by month basis, over one year. In addition to shipping-related >> influences on acidity, >> the model also included many physical and environmental factors, such as >> ocean surface >> water mixing and atmospheric effects. >> >> The results agreed with previous studies of the average annual ocean >> acidification, but, >> importantly, revealed significant differences between regions and >> seasons. Ocean >> acidification was highest in the northern hemisphere, occurring in 'hot >> spots' close to coastal >> areas and busy shipping lanes during the summer months. These 'hot spots' >> coincide with >> peak activity of some biological processes, such as plankton blooms and >> fish hatching, >> where they may cause greater harm. On a local scale, the acidification - >> a pH drop of >> 0.0015-0.0020 - was equal to CO2's global annual acidifying effects. >> >> The model did not include some coastal ocean areas, such as the >> Mediterranean Sea, as >> there were limitations in the oceanographic atlases used. However, >> acidification is likely to >> be high in these areas given the heavy shipping traffic from ports. >> >> International regulation is in place to reduce shipping atmospheric >> sulphur emissions >> through the International Maritime Organization's Emission Control Areas >> (ECA), which are >> in force in four ocean areas, including the Baltic and North Seas. One >> technology commonly >> used to achieve ECA targets is 'seawater scrubbing', where exhaust >> pollutants are removed >> using seawater. >> >> This study drew on data from 2000 and 2002, prior to the enforcement of >> ECAs. However, >> the researchers note that seawater scrubbing, without additional steps to >> neutralise the >> acids that it produces, causes acidification in regions where >> biodiversity or commercial >> aquaculture may be most negatively affected. These previously overlooked >> sources of ocean >> acidification and policy impacts could be used to inform future >> discussions of controls >> relating to shipping emissions or ocean acidification >> >> The study: >> >> *Shipping contributes to ocean acidification* >> Ida-Maja Hassellöv et al DOI: 10.1002/grl.50521 >> http://onlinelibrary.wiley.com/doi/10.1002/grl.50521/full >> http://onlinelibrary.wiley.com/doi/10.1002/grl.50521/abstract >> >> Abstract >> >> [1] The potential effect on surface water pH of emissions of SO*X* and NO >> *X* from global ship routes is assessed. The results indicate that >> regional pH reductions of the same order of magnitude as the CO2-driven >> acidification can occur in heavily trafficked waters. These findings have >> important consequences for ocean chemistry, since the sulfuric and nitric >> acids formed are strong acids in contrast to the weak carbonic acid formed >> by dissolution of CO2. Our results also provide background for >> discussion of expanded controls to mitigate acidification due to these >> shipping emissions. >> >> -- >> 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 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 geoengineering+unsubscr...@googlegroups.com. > To post to this group, send email to geoengineering@googlegroups.com. > 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. 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