Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Emergence of anthropogenic signals in the ocean carbon cycle

Nature Climate Change volume 9, pages 719–725 (2019)Cite this article

Subjects

Abstract

The attribution of anthropogenically forced trends in the climate system requires an understanding of when and how such signals emerge from natural variability. We applied time-of-emergence diagnostics to a large ensemble of an Earth system model, which provides both a conceptual framework for interpreting the detectability of anthropogenic impacts in the ocean carbon cycle and observational sampling strategies required to achieve detection. We found emergence timescales that ranged from less than a decade to more than a century, a consequence of the time lag between the chemical and radiative impacts of rising atmospheric CO2 on the ocean. Processes sensitive to carbonate chemical changes emerge rapidly, such as the impacts of acidification on the calcium carbonate pump (10 years for the globally integrated signal and 9–18 years for regionally integrated signals) and the invasion flux of anthropogenic CO2 into the ocean (14 years globally and 13–26 years regionally). Processes sensitive to the ocean’s physical state, such as the soft-tissue pump, which depends on nutrients supplied through circulation, emerge decades later (23 years globally and 27–85 years regionally).

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Venn diagram schematic of the sources of uncertainty in simulating (using an ESM approach) and observing changes in the Earth system.
Fig. 2: Percentage of ocean with emergent anthropogenic trends in ocean biogeochemical and physical variables.
Fig. 3: Global and regional ToE for globally and regionally integrated anthropogenic signals and 50% of the local anthropogenic signals for the given biogeochemical variables.
Fig. 4: ToE and signal maps for the three carbon pumps.
Fig. 5: Amplified seasonality of \(\Delta{p_{\rm{CO}_2}}\) ToE and signals.
Fig. 6: ToE and signal maps for surface versus depth-integrated chlorophyll.

Similar content being viewed by others

Data availability

The GFDL LE data that support the findings of this study are publicly available through Globus (http://poseidon.princeton.edu).

References

  1. Sarmiento, J. L., Hughes, T. M. C., Stouffer, R. J. & Manabe, S. Simulated response of the ocean carbon cycle to anthropogenic climate warming. Nature 393, 245–249 (1998).

    Article  CAS  Google Scholar 

  2. Volk, T. & Hoffert, M. I. in The Carbon Cycle and Atmospheric CO 2 : Natural Variations Archean to Present Geophysical Monograph 32 (eds Sundquist, E. T. & Broecker, W. S.) 99–110 (American Geophysical Union, 1985).

  3. Riebesell, U., Kortzinger, A. & Oschlies, A. Sensitivities of marine carbon fluxes to ocean change. Proc. Natl Acad. Sci. USA 106, 20602–20609 (2009).

    Article  CAS  Google Scholar 

  4. Gruber, N. et al. in The Global Carbon Cycle (eds Gruber, N. et al) 45–76 (Island, 2004).

  5. Doney, S. C. et al. Climate change impacts on marine ecosystems. Ann. Rev. Mar. Sci. 4, 11–37 (2011).

    Article  Google Scholar 

  6. Moore, J. K. et al. Sustained climate warming drives declining marine biological productivity. Science 359, 1139–1143 (2018).

    Article  CAS  Google Scholar 

  7. Arora, V. K. et al. Carbon–concentration and carbon–climate feedbacks in CMIP5 Earth system models. J. Clim. 26, 5289–5314 (2013).

    Article  Google Scholar 

  8. Broecker, W. S. & Peng, T.-H. Tracers in the Sea (Lamont-Doherty Geological Observatory, 1982).

  9. Battaglia, G., Steinacher, M. & Joos, F. A probabilistic assessment of calcium carbonate export and dissolution in the modern ocean. Biogeosciences 13, 2823–2848 (2016).

    Article  CAS  Google Scholar 

  10. Berelson, W. M. et al. Relating estimates of CaCO3 production, export, and dissolution in the water column to measurements of CaCO3 rain into sedimenttraps and dissolution on the sea floor: a revised global carbonate budget. Glob. Biogeochem. Cycles 21, GB1024 (2007).

    Article  Google Scholar 

  11. Sarmiento, J. L. et al. A new estimate of the CaCO3 to organic carbon export ratio. Glob. Biogeochem. Cycles 16, 1107 (2002).

    Article  Google Scholar 

  12. Dunne, J. P., Armstrong, R. A., Gnanadesikan, A. & Sarmiento, J. L. Empirical and mechanistic models for the particle export ratio. Glob. Biogeochem. Cycles 19, GB4026 (2005).

    Article  Google Scholar 

  13. Henson, S. A. et al. A reduced estimate of the strength of the ocean’s biological carbon pump. Geophys. Res. Lett. 38, L04606 (2011).

    Article  Google Scholar 

  14. Siegel, D. A. et al. Global assessment of ocean carbon export by combining satellite observations and food-web models. Glob. Biogeochem. Cycles 28, 181–196 (2014).

    Article  CAS  Google Scholar 

  15. Rödenbeck, C. et al. Data-based estimates of the ocean carbon sink variability—first results of the Surface Ocean \(p_{{\rm{CO}}_2}\); Mapping intercomparison (SOCOM). Biogeosciences 12, 7251–7278 (2015).

    Article  Google Scholar 

  16. Jones, C. et al. Twenty-first-century compatible CO2 emissions and airborne fraction simulated by CMIP5 Earth system models under four representative concentration pathways. J. Clim. 26, 4398–4413 (2013).

    Article  Google Scholar 

  17. Lovenduski, N. S., McKinley, G. A., Fay, A. R., Lindsay, K. & Long, M. C. Partitioning uncertainty in ocean carbon uptake projections: internal variability, emission scenario, and model structure. Glob. Biogeochem. Cycles 30, 1276–1287 (2016).

    Article  CAS  Google Scholar 

  18. Laufkötter, C. et al. Projected decreases in future marine export production: the role of the carbon flux through the upper ocean ecosystem. Biogeosciences 13, 4023–4047 (2016).

    Article  Google Scholar 

  19. McKinley, G. A. et al. Timescales for detection of trends in the ocean carbon sink. Nature 530, 469–472 (2016).

    Article  Google Scholar 

  20. Li, H. & Ilyina, T. Current and future decadal trends in the oceanic carbon uptake are dominated by internal variability. Geophys. Res. Lett. 45, 916–925 (2018).

    Article  CAS  Google Scholar 

  21. Frölicher, T. L., Joos, F., Plattner, G.-K., Steinacher, M. & Doney, S. C. Natural variability and anthropogenic trends in oceanic oxygen in a coupled carbon cycle-climate model ensemble. Glob. Biogeochem. Cycles 23, GB1003 (2009).

    Article  Google Scholar 

  22. Christian, J. R. Timing of the departure of ocean biogeochemical cycles from the preindustrial state. PLoS ONE 9, e109820 (2014).

    Article  Google Scholar 

  23. Rodgers, K. B., Lin, J. & Frölicher, T. L. Emergence of multiple ocean ecosystem drivers in a large ensemble suite with an Earth system model. Biogeosciences 12, 3301–3320 (2015).

    Article  Google Scholar 

  24. Long, M. C., Deutsch, C. & Ito, T. Finding forced trends in oceanic oxygen. Glob. Biogeochem. Cycles 30, 381–397 (2016).

    Article  CAS  Google Scholar 

  25. Keller, K. M., Joos, F. & Raible, C. C. Time of emergence of trends in ocean biogeochemistry. Biogeosciences 11, 3647–3659 (2014).

    Article  Google Scholar 

  26. Henson, S. A. et al. Detection of anthropogenic climate change in satellite records of ocean chlorophyll and productivity. Biogeosciences 7, 621–640 (2010).

    Article  CAS  Google Scholar 

  27. Frölicher, T. L., Rodgers, K. B., Stock, C. A. & Cheung, W. W. L. Sources of uncertainties in 21st century projections of potential ocean ecosystem stressors. Glob. Biogeochem. Cycles 30, 1224–1243 (2016).

    Article  Google Scholar 

  28. Carter, B. R. et al. When can ocean acidification impacts be detected from decadal alkalinity measurements? Glob. Biogeochem. Cycles 30, 595–612 (2016).

    Article  CAS  Google Scholar 

  29. Dunne, J. P. et al. GFDL’s ESM2 global coupled climate–carbon Earth system models. Part I: Physical formulation and baseline simulation characteristics. J. Clim. 25, 6646–6665 (2012).

    Article  Google Scholar 

  30. Dunne, J. P. et al. GFDL’s ESM2 global coupled climate–carbon Earth system models. Part II: Carbon system formulation and baseline simulation characteristics. J. Clim. 26, 2247–2267 (2013).

    Article  Google Scholar 

  31. Woods, J. D. The World Ocean Circulation Experiment. Nature 314, 501–511 (1985).

    Article  Google Scholar 

  32. Gleckler, P. J. et al. Human-induced global ocean warming on multidecadal timescales. Nat. Clim. Change 2, 524–529 (2012).

    Article  Google Scholar 

  33. Manabe, S., Bryan, K. & Spelman, M. J. Transient response of a global ocean–atmosphere model to a doubling of atmospheric carbon dioxide. J. Phys. Oceanogr. 20, 722–749 (1990).

    Article  Google Scholar 

  34. Séférian, R., Bopp, L., Swingedouw, D. & Servonnat, J. Dynamical and biogeochemical control on the decadal variability of ocean carbon fluxes. Earth Syst. Dyn. 4, 109–127 (2013).

    Article  Google Scholar 

  35. Andrews, O. D., Bindoff, N. L., Halloran, P. R., Ilyina, T. & Le Quéré, C. Detecting an external influence on recent changes in oceanic oxygen using an optimal fingerprinting method. Biogeosciences 10, 1799–1813 (2013).

    Article  CAS  Google Scholar 

  36. Sarmiento, J. L. & Gruber, N. Ocean Biogeochemical Dynamics (Princeton Univ. Press, 2006).

  37. Fassbender, A. J., Rodgers, K. B., Palevsky, H. I. & Sabine, C. L. Seasonal asymmetry in the evolution of surface ocean \(p_{{\rm{CO}}_2}\) and pH thermodynamic drivers and the influence on sea–air CO2 flux.Glob. Biogeochem. Cycles 32, 1476–1497 (2018).

    Article  CAS  Google Scholar 

  38. Gallego, M. A., Timmermann, A., Friedrich, T. & Zeebe, R. E. Drivers of future seasonal cycle changes of oceanic pco 2. Biogeosci. Discuss. 15, 5315–5327 (2018).

    Article  Google Scholar 

  39. Takahashi, T. et al. Climatological mean and decadal change in surface ocean pco2, and net sea-air CO2 flux over the global oceans. Deep Sea Res Pt II 56, 554–577 (2009).

    Article  CAS  Google Scholar 

  40. Rodgers, K. B. et al. A wintertime uptake window for anthropogenic CO2 in the North Pacific. Glob. Biogeochem. Cycles 22, GB2020 (2008).

    Google Scholar 

  41. Landschützer, P., Gruber, N., Bakker, D. C. E., Stemmler, I. & Six, K. D. Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2. Nat. Clim. Change 8, 146–150 (2018).

    Article  Google Scholar 

  42. Siegel, D. A. et al. Prediction of the export and fate of global ocean net primary production: the EXPORTS science plan. Front. Mar. Sci. 3, 4–10 (2016).

    Article  Google Scholar 

  43. Johnson, K. & Claustre, H. Bringing biogeochemistry into the Argo Age. Eos 97, https://doi.org/10.1029/2016EO062427 (2016).

  44. Hostetler, C. A., Behrenfeld, M. J., Hu, Y., Hair, J. W. & Schulien, J. A. Spaceborne lidar in the study of marine systems. Ann. Rev. Mar. Sci. 10, 121–147 (2018).

    Article  Google Scholar 

  45. Meinshausen, M. et al. The RCP greenhouse gas concentrations and their extensions from 1765 to 2300. Climatic Change 109, 213–241 (2011).

    Article  CAS  Google Scholar 

  46. McGregor, S. et al. Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming. Nat. Clim. Change 4, 888–892 (2014).

    Article  Google Scholar 

  47. England, M. H. et al. Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus. Nat. Clim. Change 4, 222–227 (2014).

    Article  Google Scholar 

  48. Penduff, T. et al. Sea level expression of intrinsic and forced ocean variabilities at interannual time scales. J. Clim. 24, 5652–5670 (2011).

    Article  Google Scholar 

  49. Majkut, J. D. et al. An observing system simulation for Southern Ocean carbon dioxide uptake. Phil. Trans. R. Soc. A 372, 20130046 (2014).

    Article  Google Scholar 

  50. Christian, J. R., Feely, R. A., Ishii, M., Murtugudde, R. & Wang, X. Testing an ocean carbon model with observed sea surface pco2 and dissolved inorganic carbon in the tropical Pacific Ocean. J. Geophys. Res. 113, C07047 (2008).

    Article  Google Scholar 

  51. Friedlingstein, P. et al. Uncertainties in CMIP5 climate projections due to carbon cycle feedbacks. J. Clim. 27, 511–526 (2014).

    Article  Google Scholar 

  52. Frölicher, T. L. et al. Dominance of the Southern Ocean in anthropogenic carbon and heat uptake in CMIP5 models. J. Clim. 28, 862–886 (2015).

    Article  Google Scholar 

  53. Bopp, L. et al. Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models. Biogeosciences 10, 6225–6245 (2013).

    Article  Google Scholar 

Download references

Acknowledgements

This work was supported by NASA award no. NNX17AI75G. Support for K.B.R. was provided by the Institute for Basic Science project code IBS-R028-D1, with additional support through NOAA award nos NA17RJ2612 and NA08OAR4320752, including support through the NOAA Office for Climate Observations and NOAA award no. NA11OAR4310066. T.L.F. acknowledges support from the Swiss National Science Foundation under grant no. PP00P2_170687. The numerical simulations were performed with the computational resources of NOAA/GFDL.

Author information

Authors and Affiliations

  1. Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, USA

    Sarah Schlunegger, Jorge L. Sarmiento & Richard Slater

  2. Center for Climate Physics, Institute for Basic Science, Busan, South Korea

    Keith B. Rodgers

  3. Pusan National University, Busan, South Korea

    Keith B. Rodgers

  4. Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland

    Thomas L. Frölicher

  5. Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland

    Thomas L. Frölicher

  6. NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA

    John P. Dunne

  7. Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan

    Masao Ishii

Authors
  1. Sarah Schlunegger
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Keith B. Rodgers
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jorge L. Sarmiento
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Thomas L. Frölicher
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. John P. Dunne
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Masao Ishii
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Richard Slater
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

S.S. performed all the analysis and writing, with regular feedback from K.B.R., J.L.S, T.L.F., J.P.D., M.I. and R.S. The LE simulations were set up by K.B.R. and T.L.F. and performed and postprocessed by K.B.R. The sensitivity experiments and control runs were performed by R.S.

Corresponding author

Correspondence to Sarah Schlunegger.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Notes 1–3, references and Figs. 1–7.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Schlunegger, S., Rodgers, K.B., Sarmiento, J.L. et al. Emergence of anthropogenic signals in the ocean carbon cycle. Nat. Clim. Chang. 9, 719–725 (2019). https://doi.org/10.1038/s41558-019-0553-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41558-019-0553-2

This article is cited by

Search

Advanced search

Quick links

Nature Briefing Microbiology

Sign up for the Nature Briefing: Microbiology newsletter — what matters in microbiology research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Microbiology