Skip to main content

Thank you for visiting 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.

Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability


An Erratum to this article was published on 02 May 2012


Systematic climate shifts have been linked to multidecadal variability in observed sea surface temperatures in the North Atlantic Ocean1. These links are extensive, influencing a range of climate processes such as hurricane activity2 and African Sahel3,4,5 and Amazonian5 droughts. The variability is distinct from historical global-mean temperature changes and is commonly attributed to natural ocean oscillations6,7,8,9,10. A number of studies have provided evidence that aerosols can influence long-term changes in sea surface temperatures11,12, but climate models have so far failed to reproduce these interactions6,9 and the role of aerosols in decadal variability remains unclear. Here we use a state-of-the-art Earth system climate model to show that aerosol emissions and periods of volcanic activity explain 76 per cent of the simulated multidecadal variance in detrended 1860–2005 North Atlantic sea surface temperatures. After 1950, simulated variability is within observational estimates; our estimates for 1910–1940 capture twice the warming of previous generation models but do not explain the entire observed trend. Other processes, such as ocean circulation, may also have contributed to variability in the early twentieth century. Mechanistically, we find that inclusion of aerosol–cloud microphysical effects, which were included in few previous multimodel ensembles, dominates the magnitude (80 per cent) and the spatial pattern of the total surface aerosol forcing in the North Atlantic. Our findings suggest that anthropogenic aerosol emissions influenced a range of societally important historical climate events such as peaks in hurricane activity and Sahel drought. Decadal-scale model predictions of regional Atlantic climate will probably be improved by incorporating aerosol–cloud microphysical interactions and estimates of future concentrations of aerosols, emissions of which are directly addressable by policy actions.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Atlantic surface temperatures.
Figure 2: External forcing of surface temperature and surface shortwave radiation linked to aerosol and volcanic changes.
Figure 3: Differences in spatial response between warm and cold Atlantic phases.
Figure 4: Magnitude and origin of forced changes in net surface shortwave radiation.


  1. Baines, P. & Folland, C. K. Evidence for a rapid global climate shift across the late 1960s. J. Clim. 20, 2721–2744 (2007)

    Article  ADS  Google Scholar 

  2. Goldenberg, S. B., Landsea, C. W., Nunez, A. M. M. & Gray, W. M. The recent increase in Atlantic hurricane activity: causes and implications. Science 293, 474–479 (2001)

    Article  ADS  CAS  Google Scholar 

  3. Ackerley, D. et al. Sensitivity of twentieth-century Sahel rainfall to sulfate aerosol and CO2 forcing. J. Clim. 24, 4999–5014 (2011)

    Article  ADS  Google Scholar 

  4. Hoerling, M. J., Hurrell, J., Eischeid, J. & Phillips, A. Detection and attribution of 20th century Northern and Southern African rainfall change. J. Clim. 19, 3989–4008 (2006)

    Article  ADS  Google Scholar 

  5. Knight, J. R., Folland, C. K. & Scaife, A. A. Climate impacts of the Atlantic Multidecadal Oscillation. Geophys. Res. Lett. 33, L17706 (2006)

    Article  ADS  Google Scholar 

  6. Knight, J. R. The Atlantic Multidecadal Oscillation inferred from the forced climate response in coupled general circulation models. J. Clim. 22, 1610–1625 (2009)

    Article  ADS  Google Scholar 

  7. Knight, J. R., Allan, R. J., Folland, C. K., Vellinga, M. & Mann, M. E. A signature of persistent natural thermohaline circulation cycles in observed climate. Geophys. Res. Lett. 32, L20708 (2005)

    Article  ADS  Google Scholar 

  8. Sutton, R. T. & Hodson, D. L. R. Atlantic Ocean forcing of North American and European summer climate. Science 309, 115–118 (2005)

    Article  ADS  CAS  Google Scholar 

  9. Ting, M., Kushnir, Y., Seager, R. & Li, C. Forced and internal twentieth-century SST trends in the North Atlantic. J. Clim. 22, 1469–1481 (2009)

    Article  ADS  Google Scholar 

  10. Trenberth, K. E. & Shea, D. J. Atlantic hurricanes and natural variability in 2005. Geophys. Res. Lett. 33, L12704 (2006)

    Article  ADS  Google Scholar 

  11. Mann, M. E. & Emanuel, K. A. Atlantic hurricane trends linked to climate change. Eos 87, 233–244 (2006)

    Article  ADS  Google Scholar 

  12. Evan, A. T., Vimont, D. J., Heidinger, A. K., Kossin, J. P. & Bennartz, R. The role of aerosols in the evolution of tropical North Atlantic Ocean temperature anomalies. Science 324, 778–781 (2009)

    Article  ADS  CAS  Google Scholar 

  13. Folland, C. K., Palmer, T. N. & Parker, D. E. Sahel rainfall and worldwide sea temperatures, 1901–85. Nature 320, 602–607 (1986)

    Article  ADS  Google Scholar 

  14. Zhang, R. & Delworth, T. L. Impact of Atlantic multidecadal oscillations on India/Sahel rainfall and Atlantic hurricanes. Geophys. Res. Lett. 33, L17712 (2006)

    Article  ADS  Google Scholar 

  15. Enfield, D. B., Nunez, A. M. M. & Trimble, J. P. The Atlantic multidecadal oscillation and its relation to rainfall and river flows in the continental US. Geophys. Res. Lett. 28, 2077–2080 (2001)

    Article  ADS  Google Scholar 

  16. Curtis, S. The Atlantic multidecadal oscillation and extreme daily precipitation over the US and Mexico during the hurricane season. Clim. Dyn. 30, 343–351 (2008)

    Article  Google Scholar 

  17. Chylek, P., Folland, C. K., Lesins, G. & Dubey, M. K. Twentieth century bipolar seesaw of the Arctic and Antarctic surface air temperatures. Geophys. Res. Lett. 37, L08703 (2010)

    Article  ADS  Google Scholar 

  18. Dong, B. W., Sutton, R. T. & Scaife, A. A. Multidecadal modulation of El Nino-Southern Oscillation (ENSO) variance by Atlantic Ocean sea surface temperatures. Geophys. Res. Lett. 33, L08705 (2006)

    ADS  Google Scholar 

  19. Chen, W., Dong, B. & Lu, R. Impact of the Atlantic Ocean on the multidecadal fluctuation of El Nino–Southern Oscillation–South Asian monsoon relationship in a coupled general circulation model. J. Geophys. Res. 115, D17109 (2010)

    Article  ADS  Google Scholar 

  20. Bjerknes, J. Atlantic air-sea interaction. Adv. Geophys. 10, 1–82 (1964)

    Article  ADS  Google Scholar 

  21. Kerr, R. A. A North Atlantic climate pacemaker for the centuries. Science 288, 1984–1985 (2000)

    Article  CAS  Google Scholar 

  22. Otterå, O. H., Bentsen, M., Drange, H. & Suo, L. External forcing as a metronome for Atlantic multidecadal variability. Nat. Geosci. 3, 688–694 (2010)

    Article  ADS  Google Scholar 

  23. Chang, C. Y., Chiang, J. C. H. & Wehner, M. F. Friedman, A. & Ruedy, R. Sulfate aerosol control of tropical Atlantic climate over the 20th century. J. Clim. 24, 2540–2555 (2011)

    Article  ADS  Google Scholar 

  24. Collins, W. J. et al. Development and evaluation of an Earth-system model - HadGEM2. Geosci. Model Dev. 4, 1051–1075 (2011)

    Article  ADS  Google Scholar 

  25. Bellouin, N. et al. Aerosol forcing in the Climate Model Intercomparison Project (CMIP5) simulations by HadGEM2-ES and the role of ammonium nitrate. J. Geophys. Res. 116, D20206 (2011)

    Article  ADS  Google Scholar 

  26. Jones, C. D. et al. The HadGEM2-ES implementation of CMIP5 centennial simulations. Geosci. Model Dev. 4, 543–570 (2011)

    Article  ADS  Google Scholar 

  27. Smith, T. M., Reynolds, R. W., Peterson, T. C. & Lawrimore, J. Improvements to NOAA’s historical merged land-ocean surface temperature analysis (1880–2006). J. Clim. 21, 2283–2296 (2008)

    Article  ADS  Google Scholar 

  28. Lohmann, U. & Feichter, J. Global indirect aerosol effects: a review. Atmos. Chem. Phys. 5, 715–737 (2005)

    Article  ADS  CAS  Google Scholar 

  29. Quaas, J. et al. Aerosol indirect effects - general circulation model intercomparison and evaluation with satellite data. Atmos. Chem. Phys. 9, 8697–8717 (2009)

    Article  ADS  CAS  Google Scholar 

  30. Sato, M., Hansen, J. E., McCormick, M. P. & Pollack, J. B. Stratospheric aerosol optical depths, 1850–1990. J. Geophys. Res. 98, 22987–22994 (1993)

    Article  ADS  Google Scholar 

Download references


We are grateful for discussion and input from D. Smith, D. Sexton, J. Murphy, M. Palmer, C. Roberts and J. Knight during the analysis and writing of this paper. We acknowledge the modelling groups, the Program for Climate Model Diagnosis and Intercomparison and the WCRP’s Working Group on Coupled Modelling for their roles in making available the WCRP CMIP3 multimodel data set. Support of this data set is provided by the Office of Science, US Department of Energy. The authors were supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101) and the EU FP7 THOR project.

Author information

Authors and Affiliations



B.B.B.B., N.J.D. and P.R.H. jointly led the analysis, produced figures and wrote the paper. T.A. and N.B. contributed additional experiments to diagnose different aspects of the aerosol forcing, provided technical and scientific insight and commented on the manuscript.

Corresponding author

Correspondence to Ben B. B. Booth.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains a Supplementary Discussion, Supplementary Figures 1-8, Supplementary Tables 1-2 and additional references. (PDF 1263 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Booth, B., Dunstone, N., Halloran, P. et al. Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability. Nature 484, 228–232 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

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