There is an excellent summary of the skill of the IPCC multi-decadal global models to predict climate over this time period in
Assessment of the reliability of climate predictions based on comparisons with historical time series by Koutsoyiannis et al. of the Department of Water Resources and Environmental Engineering at the National Technical University of Athens.
One of their conclusions is that
“….future climate projections [are] not credible”.
There is another study that can be used to assess the skill of the multi-decadal global IPCC models that are being used to define climate policy. It is
Hoerling, M.P., J.W. Hurrell,T. Xu, G.T. Bates, A.S., Phillips, 2004: Twentieth century North Atlantic climate change. Part II: Understanding the effect of Indian Ocean warming. Climate Dynamics, 23: 391–405
DOI 10.1007/s00382-004-0433-x
The abstract of that paper reads
“Ensembles of atmospheric general circulation model (AGCM) experiments are used in an effort to understand the boreal winter Northern Hemisphere (NH) extratropical climate response to the observed warming of tropical sea surface temperatures (SSTs) over the last half of the twentieth Century. Specifically, we inquire about the origins of unusual, if not unprecedented, changes in the wintertime North Atlantic and European climate that are well described by a linear trend in most indices of the North Atlantic Oscillation (NAO). The simulated NH atmospheric response to the linear trend component of tropic-wide SST change since 1950 projects strongly onto the positive polarity of the NAO and is a hemispheric pattern distinguished by decreased (increased) Arctic (middle latitude) sea level pressure. Progressive warming of the Indian Ocean is the principal contributor to this wintertime extratropical response, as shown through additional AGCM ensembles forced with only the SST trend in that sector. The Indian Ocean influence is further established through the reproducibility of results across three different models forced with identical, idealized patterns of the observed warming. Examination of the transient atmospheric adjustment to a sudden switch-on of an Indian Ocean SST anomaly reveals that the North Atlantic response is not consistent with linear theory and most likely involves synoptic eddy feedbacks associated with changes in the North Atlantic storm track. The tropical SST control exerted over twentieth century regional climate underlies the importance of determining the future course of tropical SST for regional climate change and its uncertainty. Better understanding of the extratropical responses to different, plausible trajectories of the tropical oceans is key to such efforts.”
They write in the conclusion
“….the recent warming there contains a signature of anomalous greenhouse gas forcing is suggested through analyses of ‘‘historical’’ integrations with coupled ocean-atmosphere climate models. We examined one such integration in P1, in which the NCAR Climate System Model (CSM; Boville and Gent 1998) was forced with estimates of observed time-dependent changes in sulfate aerosol and greenhouse gas concentrations. In that run, the linear trend of the simulated JFM Indian Ocean SST time series since 1950 was statistically equivalent to the observed rate of warming over the same period (see Fig. 13 of P1). Moreover, this conspicuous agreement does not appear to arise as a result of a coincidental natural variation in the CSM. Analysis of a long, control integration with this model reveals that the largest increase in tropical Indian Ocean SSTs over any 50 year period of a 1,000 year record is 0.24 C, which is less than half of the magnitude of the simulated 1950–1999 trend.
……The ability of the greenhouse-forced coupled models to replicate the observed Indian Ocean SST warming over the last half of the twentieth Century is striking. The CSM, ECHAM and HadCM3 simulated trends are 0.55 ± 0.15 C, 0.67 ± 0.11 C and 0.69 ± 0.27 C per 50 years, respectively, compared to the observed trend of 0.60 ± 0.10 C.”
Two figures from that paper present values of sea surface temperature anomalies for January through March that are the basis for their conclusions, are reproduced below
Fig. 13: Linear trends (January–March) of observed (1975–2003) and simulated (1975–2024) tropical SST from six coupled models forced under the A2 emission scenario of the IPCC TAR (2001). The contour increment is 0.3°C per 50 year, values exceeding +0.6°C per 50 year are shaded, negative trends are dashed, and the zero contour has been omitted. The model acronyms are those used by IPCC. Details for each model are at: http://ipcc-ddc.cru.uea.ac.uk/dkrz/dkrz_index.html
It is clear that the consensus of the models is for a warming of the Indian Ocean and for this to be more-or-less monotonic warming, which Hurrell et al. attribute this to greenhouse gas warming.
However, what do the the observations show? The first three figures are the SST anomaly for the globe for January 3, February 4 and March 3 2008.
From: http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.1.3.2008.gif
From: http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.2.4.2008.gif
From: http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.3.3.2008.gif
The clear conclusion is that the warming of the Indian Ocean has reversed which is a clear disagreement with the model predictions. This is yet another failure of the IPCC models and further supports the conclusion by Koutsoyiannis et al that “….future climate projections [are] not credible.”