Skip to main content

Advertisement

SpringerLink
Log in

Expert judgements on the response of the Atlantic meridional overturning circulation to climate change

  • Published:
Climatic Change Aims and scope Submit manuscript

Abstract

We present results from detailed interviews with 12 leading climate scientists about the possible effects of global climate change on the Atlantic Meridional Overturning Circulation (AMOC). The elicitation sought to examine the range of opinions within the climatic research community about the physical processes that determine the current strength of the AMOC, its future evolution in a changing climate and the consequences of potential AMOC changes. Experts assign different relative importance to physical processes which determine the present-day strength of the AMOC as well as to forcing factors which determine its future evolution under climate change. Many processes and factors deemed important are assessed as poorly known and insufficiently represented in state-of-the-art climate models. All experts anticipate a weakening of the AMOC under scenarios of increase of greenhouse gas concentrations. Two experts expect a permanent collapse of the AMOC as the most likely response under a 4×CO2 scenario. Assuming a global mean temperature increase in the year 2100 of 4 K, eight experts assess the probability of triggering an AMOC collapse as significantly different from zero, three of them as larger than 40%. Elicited consequences of AMOC reduction include strong changes in temperature, precipitation distribution and sea level in the North Atlantic area. It is expected that an appropriately designed research program, with emphasis on long-term observations and coupled climate modeling, would contribute to substantially reduce uncertainty about the future evolution of the AMOC.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

AMOC:

Atlantic meridional overturning circulation

NADW:

North Atlantic deep water

References

  • Broecker W (1991) The great ocean conveyor. Oceanograhy 4:79–89

    Google Scholar 

  • Bryden HL, Longworth HR, Cunningham SA (2005) Slowing of the Atlantic meridional overturning circulation at 25°N. Nature 438:655–657, doi:10.1038/nature04385

    Article  Google Scholar 

  • Budnitz RJ, Apostolakis G, Boore DM, Cluff LS, Coppersmith KJ, Cornell CA, Morris PA (1995) Use of technical expert panels: Applications to probabilistic seismic hazard analysis, Risk Analysis 18(4):463–469

    Google Scholar 

  • Curry R, Dickson B, Yashayaev I (2003) A change in the freshwater balance of the Atlantic Ocean over the past four decades. Nature 426:826–829

    Article  Google Scholar 

  • Curry R, Mauritzen C (2005) Dilution of the northern North Atlantic Ocean in recent decades. Science 308:1772–1774

    Article  Google Scholar 

  • Dalkey NC (1969) The use of self-ratings to improve group estimates. Technol Forecast 12:283–229

    Google Scholar 

  • Dansgaard W, Johnsen SJ, Clausen HB, Dahl-Jensen NS, Gundestrup NS, Hammer CU, Hvidberg CS, Steffensen JP, Sveinbjoernsdottir AE, Jouzel J, Bond G (1993) Evidence for general instability of past climate from a 250-kyr ice-core record. Nature 364:218–220

    Article  Google Scholar 

  • Dawes RM (1988) Rational choice in an uncertain world. Harcourt Brace Jovanovich, Orlando, FL

    Google Scholar 

  • Dickson B, Yashayaev I, Meincke J, Turrell B, Dye S, Holfort J (2002) Rapid freshening of the deep North Atlantic Ocean over the past four decades. Nature 416:832–837

    Article  Google Scholar 

  • Dickson RR, Lazier J, Meincke J, Rhines P, Swift J (1996) Long-term coordinated changes in the convective activity of the North Atlantic. Prog Oceanogr 38:241–295

    Article  Google Scholar 

  • Ganachaud A, Wunsch C (2000) Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature 408:453–457

    Article  Google Scholar 

  • Goosse H, Renssen H, Selten FM, Haarsma RJ, Opsteegh JD (2002) Potential causes of abrupt climate events: a numerical study with a three-dimensional climate model. Geophys Res Lett 29(18):1860, doi:10.1029/2002GL014993

    Article  Google Scholar 

  • Gregory J, Dixon K, Stouffer R, Weaver A, Driesschaert E, Eby M, Fichefet T, Hasumi H, Hu A, Jungclaus J, Kamenkovich I, Levermann A, Montoya M, Murakami S, Nawrath S, Oka A, Sokolov A, Thorpe R (2005) A model intercomparison of changes in the Atlantic thermohaline circulation in response to increasing atmospheric CO2 concentration. Geophys Res Lett 32:L12703.1–L12703.5, doi:10.1029/2005GL023209

    Article  Google Scholar 

  • Gregory J, Huybrechts P, Raper S (2004) Threatened loss of the Greenland ice-sheet. Nature 428:616

    Article  Google Scholar 

  • Häkkinen S, Rhines P (2004) Decline of subpolar North Atlantic circulation during the 1990s. Science 304:555–559

    Article  Google Scholar 

  • Hátún H, Sandø AB, Drange H, Hansen B, Valdimarsson H (2005) Influence of the Atlantic subpolar gyre on the thermohaline circulation. Science 309:1841–1844

    Article  Google Scholar 

  • Houghton J, Ding Y, Griggs D, Noguer M, van der Linden P, Dai X, Maskell K, Johnson C (eds) (2001) Climate change 2001: Scientific basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK

    Google Scholar 

  • Joughin I, Abdalati W, Fahnestock M (2004) Large fluctuations in speed on Greenland’s Jakobshavn Isbræ glacier. Nature 432:608–610

    Article  Google Scholar 

  • Kahneman D, Slovic P, Tversky A (eds) (1982) Judgments under uncertainty: Heuristics and biases. Cambridge University Press, Camridge, UK

    Google Scholar 

  • Keith DW (1996) When is it appropriate to combine expert judgments? Clim Change 33:139–143

    Article  Google Scholar 

  • Knutti R, Flüćkiger J, Stocker T, Timmermann A (2004) Strong hemispheric coupling of glacial climate through freshwater discharge and ocean circulation. Nature 430:851–856

    Article  Google Scholar 

  • Kuhlbrodt T, Griesel A, Montoya M, Levermann A, Hofmann M, Rahmstorf S (2007) On the driving processes of the Atlantic meridional overturning circulation. Reviews of Geophysics (in press)

  • Latif M, Röckner E, Mikolajewicz U, Voss R (2000) Tropical stabilization of the thermohaline circulation in a greenhouse warming simulation. J Climate 13:1809–1813

    Article  Google Scholar 

  • Levermann A, Griesel A, Hofmann M, Montoya M, Rahmstorf S (2005) Dynamic sea level changes following changes in the thermohaline circulation. Clim Dyn 24:347–354

    Article  Google Scholar 

  • Linstone H, Turoff M (1975) The Delphi Method: Techniques and applications. Addison-Wesley, Reading, MA

    Google Scholar 

  • Manabe S, Stouffer R (1988) Two stable equilibria of a coupled ocean-atmosphere model. J Climate 1:841–866

    Article  Google Scholar 

  • Manabe S, Stouffer R (1994) Multiple-century response of a coupled ocean-atmosphere mocel to an increase of atmospheric carbon dioxide. J Climate 7:5–23

    Article  Google Scholar 

  • McManus J, Francois R, Gherardi J-M, Keigwin L, Brown-Leger S (2004) Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes. Nature 428:834–837

    Article  Google Scholar 

  • Morgan MG, Adams PJ, Keith DW (2006) Elicitation of expert judgments of aerosol forcing. Clim Change 75:195–214

    Article  Google Scholar 

  • Morgan MG, Henrion M (1990) Uncertainty: A guide to dealing with uncertainty in quantitative risk and policy analysis. Cambridge University Press, New York

    Google Scholar 

  • Morgan MG, Keith D (1995) Subjective judgments by climate experts. Environ Sci Technol 29(10):468–476

    Google Scholar 

  • Morgan MG, Pitelka LF, Shevliakova E (2001) Elicitation of expert judgments of climate change impacts on forest ecosystems. Clim Change 49:279–307

    Article  Google Scholar 

  • Moss R, Schneider SH (2000) Uncertainties. In: Pachauri R, Taniguchi R, Tanaka K (eds) Guidance Papers on the Cross Cutting Issues of the Third Assessment Report of the IPCC. World Meteorological Organisation, Geneva, Switzerland

    Google Scholar 

  • Munk W, Wunsch C (1998) Abyssal recipes II. Deep-Sea Res, Part I 45:1977–2010

    Article  Google Scholar 

  • Petoukhov V, Claussen M, Berger A, Crucifix M, Eby M, Eliseev A, Fichefet T, Ganopolski A, Goose H, Kamenkovich I, Mokhov I, Montoya M, Mysak L, Sokolov A, Stone P, Wang Z, Weaver A (2005) EMIC Intercomparison Project (EMIP-CO2): Comparative analysis of EMIC simulations of climate and of equilibrium and transient responses to atmospheric CO2 doubling. Clim Dyn 25(4):363–385, doi:10.1007/s00382-005-0042-3

    Article  Google Scholar 

  • Rahmstorf S (1996) On the freshwater forcing and transport of the Atlantic thermohaline circulation. Clim Dyn 12:799–811

    Article  Google Scholar 

  • Rahmstorf S (1997) Risk of sea-change in the Atlantic. Nature 388:825–826

    Article  Google Scholar 

  • Rahmstorf S, Crucifix M, Ganopolski A, Goosse H, Kamenkovich I, Knutti R, Lohmann G, Marsh R, Mysak LA, Wang Z, Weaver AJ (2005) Thermohaline circulation hysteresis: a model intercomparison. Geophys Res Lett 32:L23605, doi:10.1029/2005GL023655

    Article  Google Scholar 

  • Schaeffer M, Selten FM, Opsteegh JD, Goosse H (2002) Intrinsic limits to predictability of abrupt regional climate change in IPCC SRES scenarios. Geophys Res Lett 29(16), doi:10.1029/2002GL015254

  • Spetzler CS, Stal von Holstein CAS (1975) Probability encoding in decision analysis. Manage Sci 22:340–352

    Article  Google Scholar 

  • Stocker T (1998) The seesaw effect. Science 282:61–62

    Article  Google Scholar 

  • Stommel H (1961) Thermohaline convection with two stable regimes of flow. Tellus 13:224–230

    Article  Google Scholar 

  • Stouffer R, Yin J, Gregory J, Dixon K, Spelman M, Hurlin W, Weaver A, Eby M, Flato G, Hasumi H, Hu A, Jungclaus J, Kamenkovich I, Levermann A, Montoya M, Murakami S, Nawrath S, Oka A, Peltier W, Robitaille D, Sokolov A, Vettoretti G, Weber S (2006) Investigating the causes of the response of the Thermohaline Circulation to past and future climate changes. J Climate 19:1365–1387

    Article  Google Scholar 

  • Talley L, Reid J, Robbins P (2003) Data-based meridional overturning streamfunctions for the global ocean. J Climate 16:3213–3226

    Article  Google Scholar 

  • Toggweiler J, Samuels B (1993) Is the magnitude of the deep outflow from the Atlantic Ocean actually governed by southern hemisphere winds? In: The Global Carbon Cycle. Springer, Berlin

    Google Scholar 

  • Toggweiler J, Samuels B (1995) Effect of drake passage on the global thermohaline circulation. Deep-Sea Res, Part I 42:477–500

    Article  Google Scholar 

  • Trenberth K, Caron J (2001) Estimates of meridional atmosphere and ocean heat transport. Clim Dyn 14:3433–3443

    Google Scholar 

  • Vellinga M, Wood R (2002) Global climatic impacts of a collapse of the Atlantic thermohaline circulation. Clim Change 54:251–267

    Article  Google Scholar 

  • Winton M (2003) On the climatic impact of ocean circulation. J Climate 16:2875–2889

    Article  Google Scholar 

  • Wood RA, Keen AB, Mitchell JFB, Gregory JM (1999) Changing spatial structure of the thermohaline circulation in response to atmospheric CO2 forcing in a climate model. Nature 399:572–575

    Article  Google Scholar 

  • Wu P, Wood R, Stott P (2004) Does the recent freshening trend in the North Atlantic indicate a weakening in the thermohaline circulation? Geophys Res Lett 31:L027301, doi:10.1029/2003GL018584

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. School of Earth and Ocean Sciences, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W3P6, Canada

    Kirsten Zickfeld

  2. Potsdam Institute for Climate Impact Research, Potsdam, Germany

    Kirsten Zickfeld, Anders Levermann, Till Kuhlbrodt & Stefan Rahmstorf

  3. Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, CA, USA

    M. Granger Morgan

  4. Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, Canada

    David W. Keith

Authors
  1. Kirsten Zickfeld
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Anders Levermann
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. M. Granger Morgan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Till Kuhlbrodt
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Stefan Rahmstorf
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. David W. Keith
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Kirsten Zickfeld.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Zickfeld, K., Levermann, A., Morgan, M.G. et al. Expert judgements on the response of the Atlantic meridional overturning circulation to climate change. Climatic Change 82, 235–265 (2007). https://doi.org/10.1007/s10584-007-9246-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10584-007-9246-3

Keywords

Search

Navigation