Using palaeo-climate comparisons to constrain future projections in CMIP5

G. A. Schmidt (1) , J. D. Annan (2) , P. J. Bartlein (3) , B. I. Cook (1) , Éric Guilyardi (4, 5) , J. C. Hargreaves (2) , S. P. Harrison (6, 7, 8) , Masa Kageyama (9, 10) , Allegra N. Legrande (1) , B. Konecky (11) , S. Lovejoy (12) , M. E. Mann (13) , Valérie Masson-Delmotte (9, 14) , Camille Risi (15) , D. Thompson (16) , Axel Timmermann (17) , Pascal Yiou (9, 18)

1 GISS - NASA Goddard Institute for Space Studies
2 RIGC - Research Institute for Global Change
3 University of Oregon [Eugene]
4 NCAS-Climate [Reading]
5 LOCEAN - Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques
6 SAGES - School of Archaeology, Geography and Environmental Sciences
7 Macquarie University
8 CPCC - Centre for Past Climate Change
9 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
10 CLIM - Modélisation du climat
11 Brown University
12 McGill University = Université McGill [Montréal, Canada]
13 Penn State - Pennsylvania State University
14 GLACCIOS - Glaces et Continents, Climats et Isotopes Stables
15 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
16 Department of Geosciences [University of Arizona]
17 University of Hawaii, 2525 Correa Road, Honolulu, HI 96822, United States
18 ESTIMR - Extrèmes : Statistiques, Impacts et Régionalisation

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.©Author(s) 2014.

Domaines: Climatologie; Géophysique [physics.geo-ph]

G. A. Schmidt, J. D. Annan, P. J. Bartlein, B. I. Cook, Éric Guilyardi, et al.. Using palaeo-climate comparisons to constrain future projections in CMIP5. Climate of the Past, 2014, 10 (1), pp.221-250. ⟨10.5194/cp-10-221-2014⟩. ⟨hal-01089496⟩