Greg: I don't know what you mean by saying that "this problem would seem to pale in comparison to CO2 acidification with an ocean input of about 8 GT (vs thand NOx). Also, probably dwarfed by SOx and NOx from land based generation"
I think the point of the article is the *heightened **"local" and temporal*effects of shipping emissions, specially in coastal areas close to shipping routes. Also, shipping SOx is estimated to be 16% of all global emissions (all inclusive I take it to be), perhaps *comparable to those of all road vehicles in the world*. The 16% figure from this study: Ship impacts on the marine atmosphere: insights into the contribution of shipping emissions to the properties of marine aerosol and clouds http://www.atmos-chem-phys.net/12/8439/2012/acp-12-8439-2012.pdf (Coggon et al.) As to solutions: Perhaps a change in fuel, coxed (pun intended) by regulation, would have a more immediate effect... “Thanks to decisions taken in London by the body that polices world shipping, this pollution could kill as many as a million more people in the coming decade – even though a simple change in the rules could stop it” Fred Pearce in "How 16 ships create as much pollution as all the cars in the world" (2009 DailyMail article) http://www.dailymail.co.uk/sciencetech/article-1229857/How-16-ships-create-pollution-cars-world.html By the way, he also makes the point: *“The most staggering statistic of all is that just 16 of the world’s largest ships can produce as much lung-clogging sulphur pollution as all the world’s cars.” *I don't know how accurate this statistic is, but It does re-enforce the argument for the local and temporal ocean acidification effects of shipping emissions. Best regards, Oscar E. On Wednesday, February 12, 2014 6:14:13 PM UTC-5, Greg Rau wrote: > > Thanks, Oscar. However,e stated MTs of SOX this problem would seem to > pale in comparison to CO2 acidification with an ocean input of about 8 GT > (vs thand 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:* [email protected] <javascript:> [ > [email protected] <javascript:>] on behalf of Oscar Escobar [ > [email protected] <javascript:>] > *Sent:* Wednesday, February 12, 2014 1:00 PM > *To:* [email protected] <javascript:> > *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://www.google.com/url?q=http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fgrl.50521%2Ffull&sa=D&sntz=1&usg=AFQjCNHJSxPMNe8CpfUrXOtZREvy7hx6jg> > 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 [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/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.
