Abstract
The ocean is the main source of thermal inertia in the climate system1. During recent decades, ocean heat uptake has been quantified by using hydrographic temperature measurements and data from the Argo float program, which expanded its coverage after 20072,3. However, these estimates all use the same imperfect ocean dataset and share additional uncertainties resulting from sparse coverage, especially before 20074,5. Here we provide an independent estimate by using measurements of atmospheric oxygen (O2) and carbon dioxide (CO2)—levels of which increase as the ocean warms and releases gases—as a whole-ocean thermometer. We show that the ocean gained 1.33 ± 0.20 × 1022 joules of heat per year between 1991 and 2016, equivalent to a planetary energy imbalance of 0.83 ± 0.11 watts per square metre of Earth’s surface. We also find that the ocean-warming effect that led to the outgassing of O2 and CO2 can be isolated from the direct effects of anthropogenic emissions and CO2 sinks. Our result—which relies on high-precision O2 measurements dating back to 19916—suggests that ocean warming is at the high end of previous estimates, with implications for policy-relevant measurements of the Earth response to climate change, such as climate sensitivity to greenhouse gases7 and the thermal component of sea-level rise8.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
The opportunity costs of the politics of division and disinformation in the context of the twenty-first century security deficit
SN Social Sciences Open Access 28 October 2022
-
Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition
Scientific Reports Open Access 27 December 2019
-
A refined model for the Earth’s global energy balance
Climate Dynamics Open Access 28 May 2019
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout




Data availability
Scripps APO data are available at http://scrippso2.ucsd.edu/apo-data. APOClimate data, contributions to APOOBS and ocean heat content time series are available in Extended Data Figs. 1–4 and Extended Data Tables 1–5. Model results are available upon reasonable request to R.W. (IPSL anthropogenic aerosol simulations), L.B. (IPSL-CM5A-LR), M.C.L. (CESM-LE), J.P.D. (GFDL-ESM2M) or W.K. (UVic).
Change history
19 November 2018
Editor’s Note: We would like to alert readers that the authors have informed us of errors in the paper. An implication of the errors is that the uncertainties in ocean heat content are substantially underestimated. We are working with the authors to establish the quantitative impact of the errors on the published results, at which point in time we will provide a further update.
25 September 2019
This Article has been retracted; see accompanying Retraction Note.
References
IPCC. Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, Cambridge, 2013).
Abraham, J. P. et al. A review of global ocean temperature observations: implications for ocean heat content estimates and climate change. Rev. Geophys. 51, 450–483 (2013).
Riser, S. C. et al. Fifteen years of ocean observations with the global Argo array. Nat. Clim. Chang e 6, 145–153 (2016).
Boyer, T. et al. Sensitivity of global upper-ocean heat content estimates to mapping methods, XBT bias corrections, and baseline climatologies. J. Clim. 29, 4817–4842 (2016).
Cheng, L. et al. XBT science: assessment of instrumental biases and errors. Bull. Am. Meteorol. Soc. 97, 924–933 (2016).
Keeling, R. F. & Manning, A. C. in Treatise on Geochemistry 385–404 (Elsevier, Oxford, 2014).
Forster, P. M. Inference of climate sensitivity from analysis of Earth’s energy budget. Annu. Rev. Earth Planet. Sci. 44, 85–106 (2016).
Church, J. A. et al. in Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 1137–1216 (IPCC, Cambridge Univ. Press, Cambridge, 2013).
Ishii, M. et al. Accuracy of global upper ocean heat content estimation expected from present observational data sets. Sci. Online Lett. Atmos. 13, 163–167 (2017).
Johnson, G. C. et al. Ocean heat content. Am. Meteorol. Soc. Bull. 98, S66–S68 (2017).
Desbruyères, D. G., Purkey, S. G., McDonagh, E. L., Johnson, G. C. & King, B. A. Deep and abyssal ocean warming from 35 years of repeat hydrography. Geophys. Res. Lett. 43, 10356–10365 (2016).
Cheng, L. et al. Improved estimates of ocean heat content from 1960 to 2015. Sci. Adv. 3, e1601545 (2017).
Allan, R. P. et al. Changes in global net radiative imbalance 1985–2012. Geophys. Res. Lett. 41, 5588–5597 (2014).
Palmer, M. D. Reconciling estimates of ocean heating and Earth’s radiation budget. Curr. Clim. Change Rep. 3, 78–86 (2017).
Loeb, N. G. et al. Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty. Nat. Geosci. 5, 110–113 (2012).
Battle, M. et al. Measurements and models of the atmospheric Ar/N2 ratio. Geophys. Res. Lett. 30, 1786 (2003).
Ritz, S. P., Stocker, T. F. & Severinghaus, J. P. Noble gases as proxies of mean ocean temperature: sensitivity studies using a climate model of reduced complexity. Quat. Sci. Rev. 30, 3728–3741 (2011).
Resplandy, L. et al. Constraints on oceanic meridional heat transport from combined measurements of oxygen and carbon. Clim. Dyn. 47, 3335–3357 (2016); erratum 49, 4317 (2017).
Stephens, B. B. et al. Testing global ocean carbon cycle models using measurements of atmospheric O2 and CO2 concentration. Glob. Biogeochem. Cycles 12, 213–230 (1998).
Le Quéré, C. et al. Global carbon budget 2016. Earth Syst. Sci. Data 8, 605–649 (2016).
DeVries, T. The oceanic anthropogenic CO2 sink: storage, air-sea fluxes, and transports over the industrial era. Glob. Biogeochem. Cycles 28, 631–647 (2014).
Wang, R. et al. Influence of anthropogenic aerosol deposition on the relationship between oceanic productivity and warming. Geophys. Res. Lett. 42, 10745–10754 (2015).
Rietbroek, R., Brunnabend, S.-E., Kusche, J., Schröter, J. & Dahle, C. Revisiting the contemporary sea-level budget on global and regional scales. Proc. Natl Acad. Sci. USA 113, 1504–1509 (2016).
IPCC. Climate Change 2007: Synthesis Report (eds Core Writing Team, Pachauri, R. K. & Reisinger, A.) (IPCC, Geneva, 2008).
Keeling, R. F. & Severinghaus, J. P. in The Carbon Cycle (eds Wigley, T. M. L. & Schimel, D.) 134–140 (Cambridge Univ. Press, New York, 2000).
Resplandy, L., Séférian, R. & Bopp, L. Natural variability of CO2 and O2 fluxes: what can we learn from centuries-long climate models simulations? J. Geophys. Res. Oceans 120, 384–404 (2015).
Eddebbar, Y. A. et al. Impacts of ENSO on air-sea oxygen exchange: observations and mechanisms. Glob. Biogeochem. Cycles 31, 2017GB005630 (2017).
Keeling, R. F. & Garcia, H. E. The change in oceanic O2 inventory associated with recent global warming. Proc. Natl Acad. Sci. USA 99, 7848–7853 (2002).
Bopp, L., Le Quéré, C., Heimann, M., Manning, A. C. & Monfray, P. Climate-induced oceanic oxygen fluxes: implications for the contemporary carbon budget. Glob. Biogeochem. Cycles 16, 1022 (2002).
Keeling, C. D., Piper, S. C., Whorf, T. P. & Keeling, R. F. Evolution of natural and anthropogenic fluxes of atmospheric CO2 from 1957 to 2003. Tellus B Chem. Phys. Meterol. 63, 1–22 (2011).
Levitus, S. et al. World ocean heat content and thermosteric sea level change (0–2000 m), 1955–2010. Geophys. Res. Lett. 39, L10603 (2012).
Olsen, A. et al. The Global Ocean Data Analysis Project version 2 (GLODAPv2)—an internally consistent data product for the world ocean. Earth Syst. Sci. Data 8, 297–323 (2016).
Severinghaus, J. P. Studies of the Terrestrial O 2 and Carbon Cycles in Sand Dune Gases and in Biosphere. PhD Thesis, Columbia Univ. (1995).
Hamme, R. C. & Keeling, R. F. Ocean ventilation as a driver of interannual variability in atmospheric potential oxygen. Tellus B Chem. Phys. Meterol. 60, 706–717 (2008).
Andres, R. J., Boden, T. A. & Higdon, D. A new evaluation of the uncertainty associated with CDIAC estimates of fossil fuel carbon dioxide emission. Tellus B Chem. Phys. Meterol. 66, 23616 (2014).
Keeling, R. F., Manning, A. C., Paplawsky, W. J. & Cox, A. C. On the long-term stability of reference gases for atmospheric O2/N2 and CO2 measurements. Tellus B Chem. Phys. Meterol. 59, 3–14 (2007).
Ballantyne, A. P. et al. Audit of the global carbon budget: estimate errors and their impact on uptake uncertainty. Biogeosciences 12, 2565–2584 (2015).
Bronselaer, B., Winton, M., Russell, J., Sabine, C. L. & Khatiwala, S. Agreement of CMIP5 simulated and observed ocean anthropogenic CO2 uptake. Geophys. Res. Lett. 44, 12298–12305 (2017).
Oeschger, H., Siegenthaler, U., Schotterer, U. & Gugelmann, A. A box diffusion model to study the carbon dioxide exchange in nature. Tellus 27, 168–192 (1975).
MacFarling Meure, C. et al. Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP. Geophys. Res. Lett. 33, L14810 (2006).
Wang, D., Gouhier, T. C., Menge, B. A. & Ganguly, A. R. Intensification and spatial homogenization of coastal upwelling under climate change. Nature 518, 390–394 (2015).
Ito, T., Nenes, A., Johnson, M. S., Meskhidze, N. & Deutsch, C. Acceleration of oxygen decline in the tropical Pacific over the past decades by aerosol pollutants. Nat. Geosci. 9, 443–447 (2016).
Jickells, T. D. et al. A reevaluation of the magnitude and impacts of anthropogenic atmospheric nitrogen inputs on the ocean. Glob. Biogeochem. Cycles 31, 289–305 (2017).
Somes, C. J., Landolfi, A., Koeve, W. & Oschlies, A. Limited impact of atmospheric nitrogen deposition on marine productivity due to biogeochemical feedbacks in a global ocean model. Geophys. Res. Lett. 43, 4500–4509 (2016).
Aumont, O., Ethé, C., Tagliabue, A., Bopp, L. & Gehlen, M. PISCES-v2: an ocean biogeochemical model for carbon and ecosystem studies. Geosci. Model Dev. 8, 2465–2513 (2015).
Talley, L. D. et al. Changes in ocean heat, carbon content, and ventilation: a review of the first decade of GO-SHIP global repeat hydrography. Annu. Rev. Marine Sci. 8, 185–215 (2016).
Sarmiento, J. L. & Gruber, N. Sinks for anthropogenic carbon. Phys. Today 55, 30–36 (2002).
Garcia, H. E. & Gordon, L. I. Oxygen solubility in seawater: better fitting equations. Limnol. Oceanogr. 37, 1307–1312 (1992).
Gruber, N., Sarmiento, J. L. & Stocker, T. F. An improved method for detecting anthropogenic CO2 in the oceans. Glob. Biogeochem. Cycles 10, 809–837 (1996).
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).
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).
Séférian, R., Iudicone, D., Bopp, L., Roy, T. & Madec, G. Water mass analysis of effect of climate change on air–sea CO2 fluxes: the Southern Ocean. J. Clim. 25, 3894–3908 (2012).
Kay, J. E. et al. The Community Earth System Model (CESM) large ensemble project: a community resource for studying climate change in the presence of internal climate variability. Bull. Am. Meteorol. Soc. 96, 1333–1349 (2015).
Keller, D. P., Oschlies, A. & Eby, M. A new marine ecosystem model for the University of Victoria Earth System Climate Model. Geosci. Model Dev. 5, 1195–1220 (2012).
Bopp, L. et al. Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models. Biogeosciences 10, 6225–6245 (2013).
Keller, D. P., Kriest, I., Koeve, W. & Oschlies, A. Southern Ocean biological impacts on global ocean oxygen. Geophys. Res. Lett. 43, 6469–6477 (2016).
Long, M. C., Deutsch, C. & Ito, T. Finding forced trends in oceanic oxygen. Glob. Biogeochem. Cycles 30, 381–397 (2016).
Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012).
Moore, J. K., Lindsay, K., Doney, S. C., Long, M. C. & Misumi, K. Marine ecosystem dynamics and biogeochemical cycling in the Community Earth System Model [CESM1(BGC)]: comparison of the 1990s with the 2090s under the RCP4.5 and RCP8.5 scenarios. J. Clim. 26, 9291–9312 (2013).
Rödenbeck, C., Le Quéré, C., Heimann, M. & Keeling, R. F. Interannual variability in oceanic biogeochemical processes inferred by inversion of atmospheric O2/N2 and CO2 data. Tellus B Chem. Phys. Meterol. 60, 685–705 (2008).
Hamme, R. C. Mechanisms controlling the global oceanic distribution of the inert gases argon, nitrogen and neon. Geophys. Res. Lett. 29, 35-1–35-4 (2002).
Trenberth, K. E., Fasullo, J. T., von Schuckmann, K. & Cheng, L. Insights into Earth’s energy imbalance from multiple sources. J. Clim. 29, 7495–7505 (2016).
WCRP Global Sea Level Budget Group. Global sea level budget 1993–present. Earth Syst. Sci. Data 10, 1551–1590 (2018).
Morice, C. P., Kennedy, J. J., Rayner, N. A. & Jones, P. D. Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: the HadCRUT4 data set. J. Geophys. Res. Atmos. 117, D08101 (2012).
Hansen, J., Ruedy, R., Sato, M. & Lo, K. Global surface temperature change. Rev. Geophys. 48, RG4004 (2010).
Vose, R. S. et al. NOAA’s merged land–ocean surface temperature analysis. Bull. Am. Meteorol. Soc. 93, 1677–1685 (2012).
Keeling, R. F., Körtzinger, A. & Gruber, N. Ocean deoxygenation in a warming world. Annu. Rev. Mar. Sci. 2, 199–229 (2010).
Helm, K. P., Bindoff, N. L. & Church, J. A. Observed decreases in oxygen content of the global ocean. Geophys. Res. Lett. 38, L23602 (2011).
Ito, T., Minobe, S., Long, M. C. & Deutsch, C. Upper ocean O2 trends: 1958–2015. Geophys. Res. Lett. 44, 4214–4223 (2017).
Schmidtko, S., Stramma, L. & Visbeck, M. Decline in global oceanic oxygen content during the past five decades. Nature 542, 335–339 (2017).
Acknowledgements
We thank M. Winton for useful suggestions. L.R. acknowledges support from the Climate Program Office of the National Oceanic and Atmospheric Administration (NOAA), grant NA13OAR4310219, and from the Princeton Environmental Institute. The National Center for Atmospheric Research (NCAR) is sponsored by the National Science Foundation (NSF). We also thank the people who maintain the APO time series at Scripps and the groups developing the models CESM, GFDL, IPSL and UViC, used in this study. The Scripps O2 program has been supported by a series of grants from the US NSF and the NOAA, most recently 1304270 and NA15OAR4320071. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF and NOAA. We thank the staff at the Cape Grim Baseline Air Pollution Station of the Canadian Greenhouse Gas program for collection of air samples.
Reviewer information
Nature thanks L. Cheng, F. Primeau and the other anonymous reviewer(s) for their contribution to the peer review of this work.
Author information
Authors and Affiliations
Contributions
L.R. directed the analysis of the datasets and models used here and shared responsibility for writing the manuscript; R.F.K. shared responsibility for writing the manuscript; R.W. performed simulations of anthropogenic aerosols; L.B., J.P.D., M.C.L., W.K. and A.O. provided model results. All authors contributed to the final version of the manuscript.
Corresponding author
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.
Extended data figures and tables
Extended Data Fig. 1 Effects of anthropogenic aerosols on APO.
a, Anomaly, relative to 1850 levels, in deposition of atmospheric anthropogenic aerosols (N, P and Fe) at the air–sea interface between 1960 and 2007, derived from model simulations with and without aerosols22. b, Impact of aerosol eutrophication on atmospheric O2 (solid lines) and CO2 (dashed lines) for all aerosols (black lines) and for each aerosol taken individually (coloured lines). c, Overall impact of aerosol eutrophication on ΔAPOClimate referenced to the first year that has observations (1991).
Extended Data Fig. 2 Solubility-driven changes in ocean oxygen and carbon concentrations.
a, Ocean observations of O2*, O2sat, Cpi* and Cpisat as a function of potential temperature in the Glodapv2 database32. b, OPOsat ( = O2sat + 1.1Cpisat, in grey) and the expected effects on APO owing to the combined effects of OPOsat and the thermal exchanges of N2 ( = O2sat + 1.1Cpisat – XO2 / XN2 [N2 – mean(N2)], in red). For clarity only 16 × 103 points randomly picked out of the 78,456 data points available are shown for each variable. Note that very low values of O2* (around 450 μmol kg−1) at low temperature (less than 10 °C) correspond to data collected in the Arctic Ocean, where phosphate concentrations (used for O2* calculation) are comparatively lower than in other cold ocean regions. Low O2* values in the Arctic explain the relatively low values of OPO shown in Extended Data Fig. 3a at temperatures below 10 °C.
Extended Data Fig. 3 Link between OPO, APOClimate and ocean heat.
a, c–f, OPO concentrations (yellow) and OPO concentrations at saturation based on O2 and CO2 solubility (OPOsat, grey) as a function of ocean temperature in the GLODAPv2 database32 (a) and four Earth-system models (IPSL, GFDL, CESM and UVic; c–f). Slopes give the OPO-to-temperature ratios in nmol J−1. b, The link between ΔAPOClimate and changes in ocean heat content (that is, ΔAPOClimate-to-ΔOHC ratio) in the four models is tied to their OPO-to-temperature ratios and can be constrained using the observed OPO-to-temperature of 4.45 nmol J−1 (vertical dashed lines). To avoid visual saturation, only 16,000 points, picked randomly, are shown for OPO.
Extended Data Fig. 4 Changes in APOClimate (ΔAPOClimate) and ocean heat content (ΔOHC) in four Earth-system models.
a, Simulated ΔAPOClimate (black outlines) are decomposed into the contributions (percentage of total) from changes in ocean thermal saturation (light blue) and biologically driven changes (dark blue), the latter including changes in photosynthesis/respiration and changes in ocean circulation that transport and mix gradients of biological origin. For each model, ΔAPOClimate is further decomposed into its O2, CO2 and N2 components—that is, how much of ΔAPOClimate is explained by changes in O2, CO2 and N2 air–sea fluxes due to ocean saturation changes and biologically driven changes. b, Model ΔAPOClimate-to-ΔOHC ratios over the 180 years of simulation (referenced to year 1991) in per meg per 1022 J units are: 0.85 ± 0.01 (CESM), 0.83 ± 0.01 (GFDL), 0.89 ± 0.03 (IPSL) and 0.99 ± 0.02 (UVic).
Source data
Rights and permissions
About this article
Cite this article
Resplandy, L., Keeling, R.F., Eddebbar, Y. et al. Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition. Nature 563, 105–108 (2018). https://doi.org/10.1038/s41586-018-0651-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41586-018-0651-8
Keywords
This article is cited by
-
The opportunity costs of the politics of division and disinformation in the context of the twenty-first century security deficit
SN Social Sciences (2022)
-
Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition
Scientific Reports (2019)
-
A refined model for the Earth’s global energy balance
Climate Dynamics (2019)
-
Beyond ‘Day Zero’: insights and lessons from Cape Town (South Africa)
Hydrogeology Journal (2019)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.