Marine CO 2 sources and sinks (CarboOcean IP), ocean acidification, and artificial Fe fertilization Christoph Heinze University of Bergen – Geophysical Institute and Bjerknes Centre of Climate Research

1Marine carbon sources and sinks (CarboOcean Integrated Project) – where does the human produced CO 2 end up? 2Ocean acidification – what is the impact of rising CO 2 on pH and marine ecosystems? 3Artificial Fe fertilisation – quality control of doubtful geo-engineering actions MOST FIGURES HAVE BEEN REMOVED FROM THE ORIGINAL PRESENTATION FOR THIS VERSION (TO COMPLY WITH COPY RIGHT ISSUES).

Heinze, 2004 (pers.comm.), HAMOCC4 model (developed by Maier-Reimer) ”Natural” carbon reflects biology and ocean circulation ”Anthropogenic” carbon reflects gas exchange FLUX ~  pCO 2 (ocean-atmosphere) and ocean circulation Natural vs. anthropogenic C

CARBOOCEAN: , 50 groups, Europe, Morocco, USA, Canada, 14.5 mio EUR Key objectives: Narrow down uncertainties in ocean CO 2 sources/sinks Focus on Atlantic and Southern Ocean – but: link to Europe and Globe years from now Observations, process studies, modelling, future scenarios Ocean large C reservoir (37000 GtC vs GtC on land) Seawater dissociates CO 2 into ions Given long time the ocean can buffer ca. 90% of anthropogenic CO 2 100,000 years !

CarboOcean Project Office – Bergen, Norway Scientific project manager: Scientific data manager: Financial and administrative manager: Hege Høiland

Objectives of CARBOOCEAN IP Guiding sustainable development management CO 2 emmisions Objective 5: Prediction, future assessment Initial conditions Objective 1: Short-term assessment System dynamicsBoundary conditions Objective 3: Assessment of Regional European Contribution Objective 2: Long term assessment Objective 4: Assessment of feedbacks

Core Theme 1: North Atlantic and Southern Ocean CO 2 air-sea exchange Core Theme 2: Detection of decadal-centennial Atlantic and Southern Ocean carbon inventory changes Core Theme 3:Carbon uptake and release at European regional scales Core Theme 4: Biogeochemical feedback on the oceanic carbon sinks Core Theme 5: Future scenarios for marine carbon sources and sinks Over-arching activity: Prediction Over-arching activity: Long-term assessment Over-arching activity: Short-term assessment Final Workshop Kick-Off Meeting Month Phase: Understanding Nowcast and Prediction Synopsis and Sustainment Description

Data syntheses: SOCAT & CARINA

C assessment report

Core theme 1: North Atlantic and Southern Ocean CO 2 air-sea exchange on a seasonal-to- interannual scale.

Indications for a decrease in sink strength: North Atlantic Schuster, U., and A.J. Watson, 2007, A variable and decreasing sink for atmospheric CO2 in the North, Journal of Geophysical Research, 112, C11006, doi: /2006JC Corbière, A., N. Metzl, G. Reverdin, C. Brunet, and T. Takahashi, 2007, Interannual and decadal variability of the oceanic carbon sink in the North Atlantic subpolar gyre, Tellus, 59B, 168–178. U.Schuster, A.J.Watson, N.R.Bates, A.Corbière, M.Gonzalez-Davila, N.Metzl, D.Pierrot, M. Santana-Casiano, 2009, Trends in North Atlantic sea-surface fCO2 from 1990 to 2006, Deep Sea Research II, in press.

Air-sea CO 2 flux changes also in Southern Ocean! Sink decrease inferred from observations and modelling ! LeQuéré, C., C. Rödenbeck, E. T. Buitenhuis,T. J. Conway, R. Langenfelds, A. Gomez, C. Labuschagne, M. Ramonet, T. Nakazawa, N. Metzl, N. Gillett, and M. Heimann, 2007, Saturation of the Southern Ocean CO2 sink due to recent climate change, Science, 316, 1735(2007), DOI: /science Metzl., N., 2009, Decadal Increase of oceanic carbondioxide in Southern Indian Ocean surface waters (1991–2007) Nicolas Metzl, Deep Sea Research II, in press.

Core theme 2: Detection of decadal-to- centennial Atlantic and Southern Ocean carbon inventory changes.

Mikaloff Fletcher, S.E., N. Gruber, A. R. Jacobson, M. Gloor, S. C. Doney, S. Dutkiewicz, M. Gerber, M. Follows, F. Joos, K. Lindsay, D. Menemenlis, A. Mouchet, S. A. Müller, and J. L. Sarmiento, Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport, Global Biogeochemicasl Cycles, 21, GB1010, doi: /2006GB Gerber, M., F. Joos, M. Vázquez-Rodríguez, F. Touratier, and C. Goyet, 2009, Regional air-sea fluxes of anthropogenic carbon inferred with an Ensemble Kalman Filter, Global Biogeochemicasl Cycles, 23, GB1013, doi: /2008GB Vázquez-Rodríguez, M., F. Touratier, C. Lo Monaco, D. W. Waugh, X. A. Padin, R. G. J. Bellerby, C. Goyet, N. Metzl, A. F. Ríos, and F. F. Pérez, 2009, Anthropogenic carbon distributions in the Atlantic Ocean: data-based estimates from the Arctic to the Antarctic, Biogeosciences, 6, 439–451.

Core theme 3: Carbon uptake and release at European regional scale.

Two operational modes of the “continental shelf pump” for carbon, North Sea carbon budget. Thomas, H., Y. Bozec, K. Elkalay, H. J. W. de Baar, A. V. Borges, and L.-S. Schiettecatte, 2005, Variability of the surface water partial pressure of CO2 in the North Sea, Biogeosciences, 2,

Anthropogenic carbon in the Strait of Gibraltar outflow Aït-Ameur, N., and, C. Goyet, 2006, Distribution and transport of natural and anthropogenic CO2 in the Gulf of Cádiz, Deep Sea Research II, 53, 1329– Huertas, I.E., A. F. Ríos, J. García-Lafuente, A. Makaoui, S. Rodríguez-Gálvez, A. Sánchez-Román, A. Orbi4, J. Ruíz, and F. F. Pérez, 2009, Anthropogenic and natural CO2 exchange through the Strait of Gibraltar, Biogeosciences Discuss., 6, 1021–1067.

Core theme 4: Biogeochemical feedbacks on the oceanic carbon sink

Potential alterations in biological cycling of carbon with circulation and pCO 2 change: Apparent decrease of dissolved inorganic C with pCO 2 Apparent increase of organically bound C with pCO 2 Apparent increase of nutrient utilisiation efficiency with pCO 2 Mesocosm facilities at Espegrend, Bergen Mesocosm experiments at differing atmospheric pCO 2 : ”Captering natural ecosystem communities in plastic bags and watching their behavior for changes in forcing under controlled conditions” Riebesell, U., K. G. Schulz, R. G. J. Bellerby, M. Botros, P. Fritsche, M. Meyerhöfer1, C. Neill, G. Nondal, A. Oschlies, J. Wohlers, E. Zöllner, Enhanced biological carbon consumption in a high CO2 ocean, Nature, 450|22 November 2007| doi: /nature06267

Upscaled calcification feedback to high pCO2 Gehlen, M., R. Gangstø, B. Schneider, L. Bopp, O. Aumont, and C. Ethe, 2007, The fate of pelagic CaCO3 production in a high CO2 ocean: a model study, Biogeosciences, 4, 505–519.

Rapid deep CaCO3 sediment change due to anthropogenic carbon Gehlen, M., L. Bopp, and O. Aumont, 2008, Short-term dissolution response of pelagic carbonate sediments to the invasion of anthropogenic CO2: A model study, Geochemistry Geophysics Geosystems, Volume 9, Number 2, 16 February 2008, Q02012, doi: /2007GC001756

Core theme 5: Future scenarios for marine carbon sources and sinks.

Ocean uptake slows down in most models (though it will be always positive on global average) Friedlingstein et al., 2006, Climate–Carbon Cycle Feedback Analysis: Results from the C4MIP Model Intercomparison, Journal of Climate, 19, (not CarboOcean result !) The net carbon cycle climate feedback is positive – re-enforcing climate change: (pre-CARBOOCEAN result)

New carbon climate future projections within CarboOcean, among others (on top of C4MIP runs): Frölicher, T.L., F. Joos, G.-K. Plattner, M. Steinacher, and S. C. Doney, 2009, Natural variability and anthropogenic trends in oceanic oxygen in a coupled carbon cycle–climate model ensemble, Global Biogeochemical Cycles, 23, GB1003, doi: /2008GB Bergen Climate Model with carbon, manuscript in preparation.

0 Projected undersaturation in the Arctic extends to 4000 m depth in 2100 and SRES A2 Steinacher, M., F. Joos, T. L. Frölicher, G.-K. Plattner, and S. C. Doney, 2008, Imminent ocean acidification in the Arctic projected with the NCAR global coupled carbon cycle-climate model, Biogeosciences, 6, 515–533.

2Ocean acidification – what is the impact of rising CO 2 on pH and marine ecosystems?

pH decrease in surface ocean as consequence of anthropogenic CO2 increase can be observed – example from ESTOC time series station: Santana-Casiano, J. M., M. González-Dávila, M.-J. Rueda, O. Llinás, and E.-F. González-Dávila, 2007, The interannual variability of oceanic CO2 parameters in the northeast Atlantic subtropical gyre at the ESTOC site, Global Biogeochemical Cycles, 21, GB1015, doi: /2006GB

When would be ΔpH induced loss in biocalcification measurable through Alk? (Long time frame, ca. by year 2040 in tropical ocean) Iliyna, T., R. Zeebe, E. Maier-Reimer, and C. Heinze, 2009, Early detection of ocean acidification effects on marine calcification, Global Biogeochemical Cycles, 23, GB1008, doi: /2008GB Can one use radionuclides for detection of changes in biocalcification? Heinze, C., M. Gehlen, and C. Land, 2006, On the potential of 230Th, 231Pa, and 10Be for marine rain ratio determinations: A modeling study, Global Biogeochemical Cycles, 20, GB2018, doi: /2005GB

3Artificial Fe fertilisation – quality control of doubtful geo-engineering actions

Carbon credit / artificial Fe fertilisation problem was raised recently and critically evaluated: Buesseler, et al., 2008, Ocean Iron Fertilization—Moving Forward in a Sea of Uncertainty, Science, 11 JANUARY 2008, VOL 319, /science Earlier GCM studies showing the the inefficiency of artificial Fe fertilisation of the ocean as a mitigation option: Kurz, K.D., and E. Maier-Reimer, 1993, Iron fertilization of the Austral ocean - the Hamburg model assessment, Global Biogeochemical Cycles, 7(1), Aumont, O., and L. Bopp, 2006, Globalizing results from ocean in situ iron fertilization studies, Global Biogeochemical Cycles, 20, GB2017, doi: /2005GB

Role of COST GEOTRACES for these questions? -Early detection of pH change impacts -Advice concerning CO 2 increase mitigation