I wonder if there are any historic measurements of ocean albedo which would allow the effect of these ships on ocean color to be quantified
A On Feb 9, 2013 10:32 AM, "Russell Seitz" <[email protected]> wrote: > I'm surprised *New Scientist* writer Jeff Hect failed to note my 2008 > account of inadvertant iron fertilization by smokestack fallout from ships, > which appeared in *Science* online in response to a 2007 ocean > fertilization piece by Eli Kintisch: > CARBON SEQUESTRATIONShould Oceanographers Pump Iron? > > - Eli Kintisch > > Science 30 November 2007: 1368-1370. > > - Summary <http://www.sciencemag.org/content/318/5855/1368.summary> > > > 1. > > <http://www.sciencemag.org/content/318/5855/1368.summary/reply#content-block> > Ocean Iron Fertilization > - Russell Seitz > Cambridge, MA, USA > > E. Kintisch’s article, "Should oceanographers pump iron?" (News Focus, > 30 November 2007, p. 1368) reminds us that controversy surrounds ocean > fertilization as a means of offsetting atmospheric carbon dioxide. > Biologists are skeptical, because despite the late John Martin’s famous > assertion, "Give me a half tanker of iron and I'll give you an ice age" ( > *1*), many offshore areas sequester little carbon because their waters > are perennially deficient in nitrogen and phosphorus as well. > > But Martin’s wish for a series of massive experiments may have been > realized anyway—before he was born. During the decades before oil became > the dominant marine transportation fuel, burning coal to raise steam at sea > spewed literally megatons a year of iron, nitrogen, and phosphorous into > nutrient-deficient surface waters. > > Burning coal typically generates ash equal to ~10% of the fuel mass. > In modern combustion technology, electrostatic precipitators, bag houses, > and scrubbers remove over 95% of particulates. But no effort was made to > capture fly ash in early marine propulsion, and about three-fourths was > entrained and released with hot flue gases, the rest being incorporated > into stack ash, boiler slag, and scoria (*2*). > > Owing to the low energy density of coal relative to oil, the > 50,000,000 ton fleet of coal-burning ships operating in the early 20th > century (*3*) consumed many times its displacement in fuel annually. > The efficient but ill-fated Titanic consumed 1.5% of its 42,000 tonne > displacement daily, and lesser vessels typically combusted their > displacement in bunker coal in a matter of months. The scale of marine fuel > demand was such that Europe's 1913 export of 213 million tons of bunker > coal represented less than half the world total (*4*). > > Coal ash typically contains from 2.5% to 8.5% iron (*5*). Much occurs > as pyrites (FeS2), and sulfate enrichment of ash particles by its > oxidation may enhance the bioavailability of fly ash iron. This suggests > that early 20th century European maritime activity alone annually released > ~0.39 to 2.16 teragrams of iron at sea, with a high and frequently > replenished flux of aerosol iron flux along heavily traveled shipping > lanes. > > But what of nitrogen and phosphorus? Before the Haber process > revolutionized nitrogen fixation, one of the most important fertilizers was > the ammonium sulfate inevitably co-produced with coal tar in gas works and > coke ovens. Since ship's coal typically contains 1 to 3% nitrogen, mostly > in polycyclics, the pyrolysis yield of water-soluble pyrroles, pyridine and > ammonium compounds from combustion at sea, may also have been in the > low-teragram range. Unlike metallurgical coal, the ash of that mined to > raise steam typically contained on the order of a kilogram of phosphorus > per ton. > > This suggests that the co-deposition of nutrient phosphorus and > nitrogen with iron may have at least locally met the N-P-Fe synergy > criterion for enhancement of carbon fixation. Given that literal shiploads > of fly ash fell at sea for decades, understanding what exactly was > combusted along historic shipping lanes may shed light on the risks and > benefits of the more modest CO2 sequestration experiments of today, > and perhaps add the record of another historic aerosol (*6*) to the > list of those already known to impact climate model estimates of 20th > century and future radiative forcing. > > Russell Seitz > > Cambridge, MA 02138, USA. > > References > > 1. J. H. Martin *et al*., *Nature* 371, 123 (1994). > > 2. *U.S. EPA Radiation Protection* ( > http://www.EPA.gov/rpdweb00/tenorm/coalandcoalash.html). > > 3. *Lloyds Register* ( > http://www.coltoncompany.com/shipping/statistics/wldflt.htm). > > 4. J. F. Bogardus, *Geographical Review* 20 (4), 642 (1930). > > 5. S. K. Gupta, T. F. Wall, R. A. Creelman, R. P. Gupta, *Fuel > Processing Technology* 56 (issues 1–2), 33 (1998). > > 6. R. Seitz, *Nature* 323, 116 (1986). > ... less<http://www.sciencemag.org/content/318/5855/1368.summary/reply#> > Submit > response<http://www.sciencemag.org/letters/submit/sci;318/5855/1368?title=Re:Ocean%20Iron%20Fertilization> > Published 12 May 2008 > > > > > > > > On Thursday, February 7, 2013 6:50:19 PM UTC-5, andrewjlockley wrote: >> >> Posters note : Ships apparently 'geoengineering' with iron as well as >> sulfur. Where would we be without them? >> >> http://www.newscientist.com/**article/mg21729035.100-sooty-** >> ships-may-be-geoengineering-**by-accident.html<http://www.newscientist.com/article/mg21729035.100-sooty-ships-may-be-geoengineering-by-accident.html> >> ? >> >> Sooty ships may be geoengineering by accident >> >> 06 February 2013 by Jeff Hecht >> >> Magazine issue 2903. >> >> GEOENGINEERING is being tested - albeit inadvertently - in the north >> Pacific. Soot from oil-burning ships is dumping about 1000 tonnes of >> soluble iron per year across 6 million square kilometres of ocean, new >> research has revealed.Fertilising the world's oceans with iron has been >> controversially proposed as a way of sucking carbon dioxide out of the >> atmosphere to curb global warming. Some geoengineers claim releasing iron >> into the sea will stimulate plankton blooms, which absorb carbon, but ocean >> processes are complex and difficult to monitor in tests."Experiments >> suggest you change the population of algae, causing a shift from >> fish-dominated to jellyfish-dominated ecosystems," says Alex Baker of the >> University of East Anglia, UK. Such concerns led the UN Convention on >> Biological Diversity (CBD) to impose a moratorium on geoengineering >> experiments in 2010.The annual ship deposition is much larger, if less >> concentrated, than the iron released in field tests carried out before the >> moratorium was in place. Yet because ship emissions are not intended to >> alter ocean chemistry, they do not violate the moratorium, says Jim Thomas >> of the ETC Group, a think tank that consults for the CBD. "If you >> intentionally drove oil-burning ships back and forth as a geoengineering >> experiment, that would contravene it."The new study, by Akinori Ito of >> the Japan Agency for Marine-Earth Science and Technology, is the first to >> quantify how shipping deposits iron in parts of the ocean normally >> deficient in it. Earlier models had assumed that only 1 to 2 per cent of >> the iron contained in aerosols, including shipping emissions, is soluble in >> seawater, so the remaining 98 to 99 percent would sink to the bottom >> without affecting ocean life. But Ito found that up to 80 per cent of the >> iron in shipping soot is soluble (Global Biogeochemical Cycles, >> doi.org/kdj). As this soot rapidly falls to the sea surface, it is >> likely to be fertilising the oceans.In the high-latitude north Pacific - a >> region that is naturally iron-poor and therefore likely to be most affected >> by human deposits - ship emissions now account for 70 per cent of soluble >> iron from human activity, with the burning of biomass and coal accounting >> for the rest. Shipping's share will rise as traffic continues to grow and >> regulations restrict coal and biomass emissions.Can we learn anything from >> this unintentional experiment? Baker thinks not. "The process isn't >> scientifically useful," he says, because the uncontrolled nature of the >> iron makes it difficult to draw meaningful comparisons.The depositions are >> unlikely to be harmful at current levels, he says, but "given the >> uncertainties, I just don't know how much these iron emissions would have >> to increase before there was demonstrable harm to an ecosystem, or benefit >> in terms of carbon uptake, for that matter". >> > -- > 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?hl=en. > 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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