Climatic Change

, Volume 85, Issue 1–2, pp 71–88 | Cite as

The importance of the geophysical context in statistical evaluations of climate reconstruction procedures

  • Caspar M. AmmannEmail author
  • Eugene R. Wahl


A portion of the debate about climate reconstructions of the past millennium, and in particular about the well-known Mann-Bradley-Hughes (“MBH” 1998, 1999) reconstructions, has become disconnected from the goal of understanding natural climate variability. Here, we reflect on what can be learned from recent scientific exchanges and identify important challenges that remain to be addressed openly and productively by the community. One challenge arises from the real, underlying trend in temperatures during the instrumental period. This trend can affect regression-based reconstruction performance in cases where the calibration period does not appropriately cover the range of conditions encountered during the reconstruction. However, because it is tied to a unique spatial pattern driven by change in radiative balance, the trend cannot simply be removed in the method of climate field reconstruction used by MBH on the statistical argument of preserving degrees of freedom. More appropriately, the influence from the trend can be taken into account in some methods of significance testing. We illustrate these considerations as they apply to the MBH reconstruction and show that it remains robust back to AD 1450, and given other empirical information also back to AD 1000. However, there is now a need to move beyond hemispheric average temperatures and to focus instead on resolving climate variability at the socially more relevant regional scale.


Calibration Period Proxy Data Climate Reconstruction Northern Hemisphere Temperature Amplitude Loss 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Adams JB, Mann ME, Ammann CM (2003) Proxy evidence for an El Niño-like response to volcanic forcing. Nature 426:274–278CrossRefGoogle Scholar
  2. Ammann CM, Joos F, Schimel D, Otto-Bliesner BL, Tomas R (2007) Solar influence on climate during the past millennium: results from transient simulations with the NCAR Climate System Model. Proc Nat Acad Sci 104(10):3713–3718CrossRefGoogle Scholar
  3. Briffa KR, Osborn TJ, Schweingruber FH, Harris IC, Jones PD, Shiyatov SG, Vaganov EA (2001) Low-frequency temperature variations from a northern tree ring density network. J Geophys Res 106(D3):2929–2941CrossRefGoogle Scholar
  4. Büntgen U, Esper J, Frank DC, Nicolussi K, Schmidhalter M (2005) A 1052-year tree-ring proxy for Alpine summer temperatures. Clim Dyn 25:141–153CrossRefGoogle Scholar
  5. Bürger G, Cubasch U (2005) Are multiproxy climate reconstructions robust? Geophys Res Lett 32:L23711, doi:10.1029/2005GL024155 CrossRefGoogle Scholar
  6. Bürger G, Fast I, Cubasch U (2006) Climate reconstruction by regression – 32 variations on a theme. Tellus 58A:227–235Google Scholar
  7. Casty C, Wanner H, Luterbacher J, Esper J, Boehm R (2005a) Temperature and precipitation variability in the European Alps since 1500. Int J Climatol 25:1855–1880CrossRefGoogle Scholar
  8. Casty C, Handorf D, Sempf M (2005b) Combined winter climate regimes over the North Atlantic/European sector 1766–2000. Geophys Res Lett 32:L12801CrossRefGoogle Scholar
  9. Cobb KM, Charles CD, Cheng H, Edwards RL (2003) El Niño/Southern Oscillation and tropical Pacific climate during the last millennium. Nature 424:271–276CrossRefGoogle Scholar
  10. Cook ER, D’Arrigo RD, Mann ME (2002) A well-verified, multiproxy reconstruction of the Winter North Atlantic Oscillation Index since A.D. 1400. J Climate 15:1754–1764CrossRefGoogle Scholar
  11. Corti S, Molteni F, Palmer TN (1999) Signature of recent climate change in frequencies of natural atmospheric circulation regimes. Nature 398:799–802CrossRefGoogle Scholar
  12. Crowley TJ (2000) Causes of climate over the past 1000 years. Science 289:270–277CrossRefGoogle Scholar
  13. Esper J, Wilson RJS, Frank DC, Moberg A, Wanner H, Luterbacher J (2005) Climate: past ranges and future changes. Quat Science Rev 24:2164–2166CrossRefGoogle Scholar
  14. Evans MN, Kaplan A, Cane MA (2002) Pacific sea surface temperature field reconstruction from coral d18O data using reduced space objective analysis. Paleoceanography 17(7):1–7,13Google Scholar
  15. Fischer EM, Luterbacher J, Zorita E, Tett SFB, Casty C, Wanner H (2007) European climate response to tropical volcanic eruptions over the last half millennium. Geophys Res Lett 34:L05707, doi:10.1029/2006GL027992 CrossRefGoogle Scholar
  16. Folland CK, Karl TR, Christy JR, Clarke RA, Gruza GV, Jouzel J, Mann ME, Oerlemans J, Salinger MJ, Wang S-W (2001) Observed climate variability and change. In Houghton JT et al. (eds.) Climate Change 2001: The scientific basis. Cambridge Univ. Press, Cambridge, pp 99–181Google Scholar
  17. Goosse H, Rensen H, Timmermann A, Bradley RS (2005) Internal and forced climate variability during the last millennium: a model-data comparison using ensemble simulations. Quat Sci Rev 24:1345–1360CrossRefGoogle Scholar
  18. Graham NE, Hughes MK, Ammann CM, Cobb KM, Hoerling MP, Kennett DJ, Kennett JP, Rein B, Stott L, Wigand PE, Xu T (2007) Tropical Pacific – mid-latitude teleconnections in medieval times. Climatic Change doi:10.1007/s10584-007-9239-2 (in press)
  19. Hansen et al. (2005) Earth’s energy imbalance: confirmation and implications. Science 308:1431–1435CrossRefGoogle Scholar
  20. Hegerl GC, Crowley TJ, Allen M, Hyde WT, Pollack HN, Smerdon J, Zorita E (2007) Detection of human influence on a new, validated 1500-year temperature reconstruction. J Climate 20:650–666CrossRefGoogle Scholar
  21. Hegerl GC, Crowley TJ, Baum SK, Kim K-Y, Hyde WT (2003) Detection of volcanic, solar and greenhouse gas signals in paleo-reconstructions of Nothern Hemispheric temperature. Geophys Res Lett 30(5):1242 doi:10.1029/2002GL016271 CrossRefGoogle Scholar
  22. Hurrell JW, Hoerling MP, Phillips AS, Xu T (2004) Twentieth century North Atlantic climate change. Part I: assessing determinism. Clim Dyn 23:371–389CrossRefGoogle Scholar
  23. Huybers P (2005) Comment on “Hockey sticks, principal components, and spurious significance” by McIntyre and McKitrick. Geophys Res Lett 32:L20705, doi:10.1029/2005GL023395 CrossRefGoogle Scholar
  24. Jansen E, Overpeck J, Briffa KR, Duplessy J-C, Joos F, Masson-Delmotte V, Olago D, Otto-Bliesner B, Peltier WR, Rahmstorf S, Ramesh R, Raynaud D, Rind D, Solomina O, Villalba R, Zhang D (2007) Paleoclimate. In: Solomon S., Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate Change 2007: The Physical Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USAGoogle Scholar
  25. Juckes MN, Allen MR, Briffa KR, Esper J, Hegerl GC, Moberg A, Osborn TJ, Weber SL, Zorita E (2006) Millennial temperature reconstruction intercomparison and evaluation. Clim Past Discuss 2:1001–1049Google Scholar
  26. Kaplan A, Kushnir Y, Cane MA, Blumenthal MB (1997) Reduced space optimal analysis for historical data sets: 136 years of Atlantic sea surface temperatures. J Geophys Res 102(C13):27,835–27,860CrossRefGoogle Scholar
  27. Küttel M, Luterbacher J, Zorita E, Xoplaki E, Riedwyl N, Wanner H (2007) Testing a European winter surface temperature reconstruction in a surrogate climate. Geophys Res Lett 45:L07710CrossRefGoogle Scholar
  28. Li B, Nychka DW, Ammann CM (2007) The “Hockey Stick” and the 1990s: a statistical perspective on reconstructing hemispheric temperatures. Tellus A, TeA-07-03-0034 (in press)Google Scholar
  29. Luterbacher J, Dietrich D, Xoplaki E, Grosjean M, Wanner H (2004) European seasonal and annual temperature variability, trends and extremes since1500. Science 303:1499–1503CrossRefGoogle Scholar
  30. Luterbacher J, Xoplaki E, Dietrich D, Jones PD, Davies TD, Portis D, Gonzalez-Rouco JF, von Storch H, Gyalistras D, Casty C, Wanner H (2002) Extending North Atlantic Oscillation Reconstructions back to 1500. Atmos Sci Lett 2:114–124CrossRefGoogle Scholar
  31. Mann ME, Bradley RS, Hughes MK (1998) Global-scale temperature patterns and climate forcing over the past six centuries. Nature 392:779–787CrossRefGoogle Scholar
  32. Mann ME, Bradley RS, Hughes MK (1999) Northern Hemisphere temperatures during the past millennium: inferences, uncertainties, and limitations. Geophys Res Lett 26:759–762CrossRefGoogle Scholar
  33. Mann ME, Bradley RS, Hughes MK (2000) Long-term variability in the El Niño Southern Oscillation and associated teleconnections. In Diaz HF, Markgraf V (eds) El Niño and the Southern Oscillation: Multiscale Variability and its Impacts on Natural Ecosystems and Society, Cambridge University Press, Cambridge, UK, pp 357–412Google Scholar
  34. Mann ME, Cane MA, Zebiak SE, Clement A (2005a) Volcanic and solar forcing of the tropical Pacific over the past 1000 years. J Climate 18:447–456CrossRefGoogle Scholar
  35. Mann ME, Rutherford S, Wahl E, Ammann C (2005b) Testing the fidelity of methods used in "proxy"-based reconstructions of past climate. J Climate 18:4097–4107CrossRefGoogle Scholar
  36. Mann ME, Rutherford S, Wahl ER, Ammann CM (2007) Robustness of proxy-based climate field reconstruction methods. J Geophys Res (in press)Google Scholar
  37. McIntyre S, McKitrick R (2003) Corrections to the Mann et al (1998) proxy data based and Northern Hemispheric average temperature series. Energy and Environment 14:751–771CrossRefGoogle Scholar
  38. McIntyre S, McKitrick R (2005a) Hockey sticks, principal components, and spurious significance. Geophys Res Lett 32:L03710, doi:10.1029/2004GL021750 CrossRefGoogle Scholar
  39. McIntyre S, McKitrick R (2005b) The M&M critique of the MBH98 Northern Hemisphere climate index: update and implications. Energy and Environment 16:69–100CrossRefGoogle Scholar
  40. McIntyre S, McKitrick R (2005c) Reply to comment by Huybers. Geophys Res Lett 32:L20713, doi:10.1029/2005GL023586 CrossRefGoogle Scholar
  41. Mears CA, Wentz FJ (2005) The effect of diurnal correction on satellite-derived lower tropospheric temperature. Science 309:5740, doi:10.1126/science.1114772 CrossRefGoogle Scholar
  42. Meehl GA, Washington WM, Ammann CM, Arblaster JM, Wigley TML, Tebaldi C (2004) Combinations of natural and anthropogenic forcings in twentieth-century climate. J Climate 17:3721–3727CrossRefGoogle Scholar
  43. Moberg A, Sonechkin D, Holmgren K, Datsenko N, Karlén W (2005) Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data. Nature 433:613–617CrossRefGoogle Scholar
  44. National Research Council Report (2006) Surface temperature reconstructions for the last 2,000 years. Committee on surface temperature reconstructions for the last 2,000 years, Board on Atmospheric Sciences and Climate, Division of Earth and Life Studies. The National Academies PressGoogle Scholar
  45. Osborn TJ, Briffa KR (2006) The spatial extent of 20th-century warmth in the context of the past 1200 years. Science 311:841–844CrossRefGoogle Scholar
  46. Palmer TN (1999) A nonlinear perspective on climate change. J Clim 12:575–591CrossRefGoogle Scholar
  47. Pauling A, Luterbacher J, Casty C, Wanner H (2006) 500 years of gridded high-resolution precipitation reconstructions over Europe and the connection to large-scale circulation. Clim Dynam 26:387–405CrossRefGoogle Scholar
  48. Rutherford S, Mann ME, Delworth TL, Stouffer RJ (2003) Climate field reconstruction under stationary and nonstationary forcing. J Climate 16:462–479CrossRefGoogle Scholar
  49. Rutherford S, Mann ME, Osborn TJ, Bradley RS, Briffa KR, Hughes MK, Jones PD (2005) Proxy-based Northern Hemisphere surface temperature reconstructions: sensitivity to method, predictor network, target season, and target domain. J Climate 18:2308–2329CrossRefGoogle Scholar
  50. Santer BD, Wehner MF, Wigley TML, Sausen R, Meehl GA, Taylor KE, Ammann CM, Arblaster J, Washington WM, Boyle JS, Brüggemann W (2003) Contributions of anthropogenic and natural forcing to recent tropopause height changes. Science 301:479–483CrossRefGoogle Scholar
  51. Schneider T (2001) Analysis of incomplete climate data: estimation of mean values and covariance matrices and imputation of missing values. J Climate 14:853–887CrossRefGoogle Scholar
  52. Stephenson DB, Hannachi A, O’Neill A (2004) On the existence of multiple climate regimes. QJR Meteorol Soc 130:583–606CrossRefGoogle Scholar
  53. Stott PA, Jones GS, Lowe JA, Thorne P, Durman C, Johns TC, Thelen J-C (2006) Transient climate simulations with the HadGEM1 climate model: causes of past warming and future climate change. J Climate 19(12):2763–2782CrossRefGoogle Scholar
  54. Tett SFB, Stott PA, Allen MR, Ingram WJ, Mitchell JFB (1999) Causes of twentieth-century temperature change near the Earth’s surface. Nature 399:569–572CrossRefGoogle Scholar
  55. Von Storch H, Zorita E, Jones JM, Gonzalez-Rouco F, Tett SFB (2006) Response to Comment on “Reconstructing past climate from noisy data. Science 312:529CrossRefGoogle Scholar
  56. Von Storch H, Zorita E, Jones JM, Dimitriev Y, Gonzalez-Rouco F, Tett SFB (2004) Reconstructing past climate from noisy data. Science 306:679–682CrossRefGoogle Scholar
  57. Wahl ER, Ritson D, Ammann CM (2006) Comment on ’Reconstructing Past Climate from Noisy Data. Science 312, doi:10.1126/science.1120866, 2006
  58. Wahl ER, Ammann CM (this volume) Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence. Climatic Change, (in press)Google Scholar
  59. Wegman EJ, Scott DW, Said YH (2006) Ad hoc committee report on the “Hockey Stick” global climate reconstruction. Report delivered to the Chairman of the United States House of Representatives Committee on Energy and Commerce, as well as the Chairman of the Subcommittee on Oversight and Investigations , July 14, 2006. (non peer-reviewed). Available:
  60. Xoplaki E, Luterbacher J, Paeth H, Dietrich D, Steiner N, Grosjean M, Wanner H (2005) European spring and autumn temperature variability and change of extremes over the last half millennium. Geophys Res Lett 32:L15713CrossRefGoogle Scholar
  61. Zorita E, von Storch H (2005) Methodical aspects of reconstructing non–local historical temperatures. Mem SA It 76:794. Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.Climate and Global Dynamics DivisionNational Center for Atmospheric ResearchBoulderUSA
  2. 2.Environmental Studies and Geology DivisionAlfred UniversityAlfredUSA

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