Thursday, April 30, 2015

Combustion Aerosols as a Source of Bioavailable Iron Re. (Unintended) Ocean Iron Fertilization Climate Geoengineering

By Oscar Escobar - April 30, 2015
Last update September 10, 2015


Recently in an informal conversation with someone dear to me, I was asked to summarize climate geoengineering in 140 characters or words. I took it as meaning one twitt:



SRM and OIF climate geoengineering "we" are already doing it with fossil fuel aerosols but we ignore that fact.


I should have said: 'we like' to ignore that fact.



Two studies that encompass both the Northern and Southern oceans partly explain some of the reasons of why I have arrived at that conclusion. (See full abstracts and links below my comments)

The study centered on the Northern oceans states: 

"Due to continuing growth in global shipping and no regulations regarding particles emissions over the open ocean, the input of potentially bioavailable iron from ship plumes is likely to increase during the next century. The model results suggest suggest that deposition of soluble iron from ships in 2100 contributes 30–60% of the soluble iron deposition over the high‐latitude North Atlantic and North Pacific".

This study prompted the New Scientist article "Sooty ships may be geoengineering by accident"
in which Jeff Hecht writes:

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 results of the study centered on the Southern oceans:

"suggest that deposition of soluble iron from combustion sources contributes more than 40% of the total soluble iron deposition over significant portions of the open ocean in the Southern Hemisphere". 


My comments:

As I said before here on this blog and in my twitter feed: I think that 'we' are already geoengineering the oceans via iron fertilization (and the atmosphere i.e. SRM in other posts).


Regardless of the Intentionality issue, that implies that all the concerns related to the environment i.e. marine ecosystems, and all the questions of climate justice i.e. responsibilities/liabilities/reparations and all the concerns like those voiced by The Convention on Biological Diversity and groups like the ETC apply. 

Apply but are not governed; and they will not be governed as long as they remain willfully ignored or under the shroud of being 'non-intentional' effects.



The abstracts and links:

Global modeling study of potentially bioavailable iron input from shipboard aerosol sources to the ocean 
Akinori Ito1 Received 2 April 2012; revised 27 September 2012; accepted 4 November 2012; published 18 January 2013. [1] 


Iron (Fe) is an essential element for phytoplankton. The majority of iron is transported from arid and semiarid regions to the open ocean, but it is mainly in an insoluble form. Since most aquatic organisms can take up iron only in the dissolved form, aerosol iron solubility is a key factor that can influence the air‐sea CO2 fluxes and thus climate. 

Field observations have shown relatively high iron solubility in aerosols influenced by combustion sources, but specific emissions sources and their contributions to deposition fluxes largely remain uncertain. Here a global chemical transport model was used to investigate the effect of aerosol emissions from ship plumes on iron solubility in particles from the combustion and dust sources. 

The model results reveal that the oil combustion from shipping mainly contributes to high iron solubility (>10%) at low iron loading (1–110ngm–3 ) observed over the high‐latitude North Atlantic Ocean, rather than the other combustion sources from continental industrialized regions. Due to continuing growth in global shipping and no regulations regarding particles emissions over the open ocean, the input of potentially bioavailable iron from ship plumes is likely to increase during the next century. The model results suggest that deposition of soluble iron from ships in 2100 contributes 30–60% of the soluble iron deposition over the high‐latitude North Atlantic and North Pacific. 

Citation: Ito, A. (2013), Global modeling study of potentially bioavailable iron input from shipboard aerosol sources to the ocean, Global Biogeochem. Cycles, 27, 1–10, doi: 10.1029/2012GB004378.




Atmospheric Processing of Combustion Aerosols as a Source of Bioavailable Iron

Yokohama Institute for Earth Sciences, JAMSTEC, Yokohama, Kanagawa 236-0001, Japan
Environ. Sci. Technol. Lett.20152 (3), pp 70–75
DOI: 10.1021/acs.estlett.5b00007
Publication Date (Web): February 2, 2015
Copyright © 2015 American Chemical Society
*E-mail: akinorii@jamstec.go.jp. Phone: (+81)457785717. Fax: (+81)457785707.

ACS AuthorChoice - This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.

Abstract

Abstract Image
Atmospheric processing of combustion aerosols may promote transformation of insoluble iron into soluble forms. Here, an explicit scheme for iron dissolution of combustion aerosols due to photochemical reactions with inorganic and organic acids in solution is implemented in an atmospheric chemistry transport model to estimate the atmospheric sources of bioavailable iron. The model results suggest that deposition of soluble iron from combustion sources contributes more than 40% of the total soluble iron deposition over significant portions of the open ocean in the Southern Hemisphere. A sensitivity simulation using half the iron dissolution rate for combustion aerosols results in relatively small decreases in soluble iron deposition in the ocean, compared with the large uncertainties associated with iron solubility at emission. More accurate quantification of the soluble iron burdens near the source regions and the open ocean is needed to improve the process-based understanding of the chemical modification of iron-containing minerals.

Link: Ihttp://pubs.acs.org/doi/abs/10.1021/acs.estlett.5b00007


Sooty ships may be geoengineering by accident



One more study:
Added May 3 (My emphasys)


Sources, transport and deposition of iron in the global atmosphere

R. Wang1,2,3, Y. Balkanski1,3, O. Boucher4, L. Bopp1, A. Chappell5, P. Ciais1,3, D. Hauglustaine1, J. Peñuelas6,7, and S. Tao2,3

Abstract. Atmospheric deposition of iron (Fe) plays an important role in controlling oceanic primary productivity. However, the sources of Fe in the atmosphere are not well understood. In particular, the combustion sources of Fe and their deposition over oceans are not accounted for in current biogeochemical models of the carbon cycle. Here we used a mass-balance method to estimate the emissions of Fe from the combustion of fossil fuels and biomass by accounting for the Fe contents in fuel and the partitioning of Fe during combustion. The emissions of Fe attached to aerosols from combustion sources were estimated by particle size, and their uncertainties were quantified by a Monte Carlo simulation. The emissions of Fe from mineral sources were estimated using the latest soil mineralogical database to date. As a result, the total Fe emissions from combustion averaged for 1960–2007 were estimated to be 5.1 Tg yr−1 (90% confidence of 2.2 to 11.5). Of these emissions, 2, 33 and 65% were emitted in particles <1 μm (PM1), 1–10 μm (PM1−10), and >10 μm (PM>10), respectively, compared to total Fe emissions from mineral sources of 41.0 Tg yr−1. For combustion sources, different temporal trends were found in fine and medium-to-coarse particles, with a notable increase in Fe emissions in PM1 and PM1−10 since 2000 due to a rapid increase from motor vehicles. These emissions have been introduced in a global 3-D transport model run at a spatial resolution of of 0.94° latitude by 1.28° longitude to evaluate our estimation of Fe emissions. The modelled Fe concentrations were compared to measurements at 825 sampling stations. The deviation between modelled and observed Fe concentrations attached to aerosols at the surface was within a factor of two at most sampling stations, and the deviation was within a factor of 1.5 at sampling stations dominated by combustion sources. We analyzed the relative contribution of combustion sources to total Fe concentrations over different regions of the world. The new mineralogical database led to a modest improvement in the simulation relative to station data even in dust dominated regions, but could provide useful information on the chemical forms of Fe in dust for coupling with ocean biota models. We estimated a total Fe deposition sink of 8.4 Tg yr−1 over global oceans, 6.6% of which originated from the combustion sources. The higher than previously estimated combustion-related Fe emissions implies a larger atmospheric input of soluble Fe over the northern Atlantic and northern Pacific Oceans, which is expected to enhance the biological carbon pump in those regions.


Citation: Wang, R., Balkanski, Y., Boucher, O., Bopp, L., Chappell, A., Ciais, P., Hauglustaine, D., Peñuelas, J., and Tao, S.: Sources, transport and deposition of iron in the global atmosphere, Atmos. Chem. Phys. Discuss., 15, 7645-7705, doi:10.5194/acpd-15-7645-2015, 2015.

PDF full study: 



Edited May 3, 2015
notwhistanding


Updates:

 September 10, 2015 (2)
(This may be related to the anthropogenic bioavailable iron from combustion)
 Southern Ocean carbon sink bounces back with renewed vigour, study says
Sep 2015, 19:00 by Robert McSweeney - The Carbon Brief http://www.carbonbrief.org/blog/2015/09/southern-ocean-carbon-sink-bounces-back-with-renewed-vigour/


Delivery of anthropogenic bioavailable iron from mineral dust and combustion aerosols to the ocean
A. Ito1 and Z. Shi2 2015 (doi:10.5194/acpd-15-23051-2015)
http://www.atmos-chem-phys-discuss.net/15/23051/2015/acpd-15-23051-2015.pdf
 

July 22, 2015
Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo
Science Advances 17 Jul 2015: Vol. 1, no. 6, e1500157 DOI: 10.1126/sciadv.1500157
http://advances.sciencemag.org/content/1/6/e1500157


June 16, 2015
Framing an ethics of climate management for the anthropocene
Christopher J. Preston -Date: 26 Jun 2014 - DOI 10.1007/s10584-014-1182-4








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