Articles | Volume 10, issue 1
Clim. Past, 10, 221–250, 2014

Special issue: Progress in paleoclimate modelling

Clim. Past, 10, 221–250, 2014

Research article 05 Feb 2014

Research article | 05 Feb 2014

Using palaeo-climate comparisons to constrain future projections in CMIP5

G. A. Schmidt1, J. D. Annan2, P. J. Bartlein3, B. I. Cook1, E. Guilyardi4,5, J. C. Hargreaves2, S. P. Harrison6,7, M. Kageyama8, A. N. LeGrande1, B. Konecky9, S. Lovejoy10, M. E. Mann11, V. Masson-Delmotte8, C. Risi12, D. Thompson13, A. Timmermann14, L.-B. Tremblay10, and P. Yiou8 G. A. Schmidt et al.
  • 1NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA
  • 2Research Institute for Global Change, JAMSTEC, Yokohama Institute for Earth Sciences, Yokohama, Japan
  • 3University of Oregon, Eugene, OR 97403, USA
  • 4NCAS-Climate, University of Reading, Whiteknights, P.O. Box 217, Reading, Berkshire, RG6 6AH, UK
  • 5Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques/Institut Pierre Simon Laplace, CNRS-IRD-UPMC – UMR7617, 4 place Jussieu, 75252 Paris Cedex 05, France
  • 6Centre for Past Climate Change and School of Archaeology, Geography and Environmental Sciences (SAGES), University of Reading, Whiteknights, P.O. Box 217, Reading, Berkshire, RG6 6AH, UK
  • 7Macquarie University, Sydney, NSW 2109, Australia
  • 8Laboratoire des Sciences du Climat et de l'Environnement, Institut Pierre Simon Laplace, CEA-CNRS-UVSQ – UMR8212, CE Saclay l'Orme des Merisiers, 91191 Gif-sur-Yvette, France
  • 9Brown University, 324 Brook St., P.O. Box 1846, Providence, RI 02912, USA
  • 10McGill University, 805 Sherbrooke Street West Montreal, Quebec, H3A 0B9, Canada
  • 11Pennsylvania State University, University Park, PA 16802, USA
  • 12Laboratoire de Météorologie Dynamique/Institut Pierre Simon Laplace, 4, place Jussieu, 75252 Paris Cedex 05, France
  • 13University of Arizona, Department of Geosciences, Gould-Simpson Building #77, 1040 E 4th St., Tucson, AZ 85721, USA
  • 14University of Hawaii, 2525 Correa Road, Honolulu, HI 96822, USA

Abstract. We present a selection of methodologies for using the palaeo-climate model component of the Coupled Model Intercomparison Project (Phase 5) (CMIP5) to attempt to constrain future climate projections using the same models. The constraints arise from measures of skill in hindcasting palaeo-climate changes from the present over three periods: the Last Glacial Maximum (LGM) (21 000 yr before present, ka), the mid-Holocene (MH) (6 ka) and the Last Millennium (LM) (850–1850 CE). The skill measures may be used to validate robust patterns of climate change across scenarios or to distinguish between models that have differing outcomes in future scenarios. We find that the multi-model ensemble of palaeo-simulations is adequate for addressing at least some of these issues. For example, selected benchmarks for the LGM and MH are correlated to the rank of future projections of precipitation/temperature or sea ice extent to indicate that models that produce the best agreement with palaeo-climate information give demonstrably different future results than the rest of the models. We also explore cases where comparisons are strongly dependent on uncertain forcing time series or show important non-stationarity, making direct inferences for the future problematic. Overall, we demonstrate that there is a strong potential for the palaeo-climate simulations to help inform the future projections and urge all the modelling groups to complete this subset of the CMIP5 runs.