New paper finds climate models are unable to reproduce the known climate of the past 6,000 years — Published in Climate of the Past

New paper finds climate models are unable to reproduce the known climate of the past 6,000 years

http://hockeyschtick.blogspot.com/2013/08/new-paper-finds-climate-models-are.html

A new paper published in Climate of the Past finds climate models are unable to reproduce the climate change of the past 6,000 years found by temperature proxies. According to the authors, “Independently of the choice of the climate model, we observe significant mismatches between modelled and estimated SST [Sea Surface Temperature] amplitudes in the trends for the last 6,000 years,” and climate model “SST trends underestimate the [proxy] SST trends by a factor of two to five. For [a different proxy], no significant relationship between model simulations and proxy reconstructions can be detected.” The paper adds to many other peer-reviewed papers finding climate models are unable to reproduce the known climate of the past, much less the future. 

Clim. Past, 9, 1807-1839, 2013www.clim-past.net/9/1807/2013/doi:10.5194/cp-9-1807-2013

A model–data comparison of the Holocene global sea surface temperature evolutionG. Lohmann1, M. Pfeiffer1, T. Laepple1, G. Leduc2, and J.-H. Kim31Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bussestrasse 24, 27570 Bremerhaven, Germany2Kiel University, Institute of Earth Sciences, Ludewig-Meyn-Str. 10, 24118 Kiel, Germany3Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, the NetherlandsAbstract. We compare the ocean temperature evolution of the Holocene as simulated by climate models and reconstructed from marine temperature proxies. We use transient simulations from a coupled atmosphere–ocean general circulation model, as well as an ensemble of time slice simulations from the Paleoclimate Modelling Intercomparison Project. The general pattern of sea surface temperature (SST) in the models shows a high-latitude cooling and a low-latitude warming. The proxy dataset comprises a global compilation of marine alkenone- and Mg/Ca-derived SST estimates. Independently of the choice of the climate model, we observe significant mismatches between modelled and estimated SST amplitudes in the trends for the last 6000 yr. Alkenone-based SST records show a similar pattern as the simulated annual mean SSTs, but the simulated SST trends underestimate the alkenone-based SST trends by a factor of two to five. For Mg/Ca, no significant relationship between model simulations and proxy reconstructions can be detected. We test if such discrepancies can be caused by too simplistic interpretations of the proxy data. We explore whether consideration of different growing seasons and depth habitats of the planktonic organisms used for temperature reconstruction could lead to a better agreement of model results with proxy data on a …