Geological carbon sinks.

Ridgwell, Andy; Edwards, U

doi:10.1079/9781845931896.0074

Cited by 14 publications

(7 citation statements)

References 54 publications

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“…2). In the following calculations, we assume that the modern ratio of buried C org to primary production of C org (~0.001; Ridgwell and Edwards, 2007) is applicable and scales linearly with production. Assuming a low Fe/C org ratio of 2 µmol mol -1 for phytoplankton (Cassar et al, 2007), burial of 10 18 g of C org may be accounted for by fertilization of HNLC areas by the adsorbed iron on ~40% of the IFU ash erupted during the post-Oi-1 carbon isotopic anomaly.…”

Section: Paleogene Global Cooling and The Ignimbrite Flare-up Of Soutmentioning

confidence: 99%

Climate forcing by iron fertilization from repeated ignimbrite eruptions: The icehouse–silicic large igneous province (SLIP) hypothesis

et al. 2009

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During middle Eocene to middle Miocene time, development of the Cenozoic icehouse was coincident with a prolonged episode of explosive silicic volcanism, the ignimbrite fl are-up of southwestern North America. We present geochronologic and biogeochemical data suggesting that, prior to the establishment of full glacial conditions with attendant increased eolian dust emission and oceanic upwelling, iron fertilization by great volumes of silicic volcanic ash was an effective climatic forcing mechanism that helped to establish the Cenozoic icehouse. Most Phanerozoic cool-climate episodes were coeval with major explosive volcanism in silicic large igneous provinces, suggesting a common link between these phenomena.

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Section: Paleogene Global Cooling and The Ignimbrite Flare-up Of Soutmentioning

confidence: 99%

Climate forcing by iron fertilization from repeated ignimbrite eruptions: The icehouse–silicic large igneous province (SLIP) hypothesis

et al. 2009

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“…Calcium carbonate skeletons provide the foundation of much marine life. These accumulate from the oceans to form the carbonate reservoir of Ca and carbon, five orders of magnitude larger than the ocean‐atmosphere reservoir [ Ridgwell and Edwards , 2007]. The dominant size of the carbonate reservoir makes it of critical importance for the balance of carbon between the solid Earth and ocean‐atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Calcium isotope ratios in the world's largest rivers: A constraint on the maximum imbalance of oceanic calcium fluxes

Tipper¹,

Gaillardet

Galy

et al. 2010

Global Biogeochemical Cycles

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[1] The oceanic mass balance of calcium (Ca) is defined by a balance between the inputs (rivers and hydrothermal) and outputs (bulk carbonate) of Ca. Large rivers were analyzed for Ca isotope ratios ( 44 Ca/ 42 Ca, expressed as d 44 42 Ca) to investigate the source and cycling of riverine Ca, and to add an isotopic mass balance constraint to the oceanic budget of Ca. The new data account for approximately one-third of the total Ca supplied to the oceans by rivers. Inter-sample and seasonal variability was assessed by analyzing more than one sample for many rivers. The range in the d Ca value of bulk carbonate and the riverine input at the current level of uncertainty. The input and output fluxes could be imbalanced over much shorter time-scales (such as glacial-interglacial cycles), in which case the ocean-carbonate system will not yet have responded, because of the long residence time of Ca. The maximum current flux imbalance of 15% would be sufficient to account for the total variations in Ca concentration over the Tertiary. Such an interpretation is not unique, but is the simplest interpretation given the similarity between the input and output isotopic compositions, and rules out hypotheses of extreme imbalance in the recent global biogeochemical cycle of Ca.Citation: Tipper, E. T., J. Gaillardet, A. Galy, P. Louvat, M. J. Bickle, and F. Capmas (2010), Calcium isotope ratios in the world's largest rivers: A constraint on the maximum imbalance of oceanic calcium fluxes, Global Biogeochem. Cycles, 24, GB3019,

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“…Then, would this weathering feedback be effective in alleviating future ocean acidification by buffering the decline in ocean pH? This question is largely unresolved because weathering fluxes were typically prescribed as constant [i.e., Archer et al, 1998;Archer, 2005;Ridgwell and Edwards, 2007] or omitted in previous model simulations [i.e., Caldeira and Wickett, 2005;Montenegro et al, 2007;Tyrrell et al, 2007]. Studies by Walker and Kasting [1992], Lenton and Britton [2006] and Zeebe et al [2008] represent a few model simulations in which weathering fluxes were set to co-vary with pCO 2 (and with plant productivity in Lenton and Britton [2006]).…”

Section: Introductionmentioning

confidence: 99%

Influence of terrestrial weathering on ocean acidification and the next glacial inception

Uchikawa¹,

Zeebe²

2008

Geophysical Research Letters

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[1] Ocean uptake of anthropogenic CO 2 causes a decline in seawater pH, a process known as ocean acidification, which may adversely affect marine organisms. We investigate whether continental weathering can mitigate future ocean acidification by sequestering atmospheric CO 2 . We conducted simulations under a suite of carbon emission scenarios with different weathering parameterizations. The short-term impact of a strong weathering feedback was only notable for large emissions with slow injection. This mitigation by enhanced weathering, however, is an order of magnitude smaller than the expected maximum pH decline based on the default parameterizations. Thus on short timescales, weathering has little effect on future atmospheric CO 2 and ocean acidification, regardless of the assumed weathering feedback strength. But on longer timescales and for large emissions, different weathering parameterizations introduce large uncertainties regarding the time when pCO 2 will return to climatically relevant levels of, say, 400 matm in the future. Citation: Uchikawa, J., and R. E. Zeebe (2008), Influence of terrestrial weathering on ocean acidification and the next glacial inception, Geophys. Res. Lett., 35, L23608,

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Geological carbon sinks.

Cited by 14 publications

References 54 publications

Climate forcing by iron fertilization from repeated ignimbrite eruptions: The icehouse–silicic large igneous province (SLIP) hypothesis

Climate forcing by iron fertilization from repeated ignimbrite eruptions: The icehouse–silicic large igneous province (SLIP) hypothesis

Calcium isotope ratios in the world's largest rivers: A constraint on the maximum imbalance of oceanic calcium fluxes

Influence of terrestrial weathering on ocean acidification and the next glacial inception

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