Update 2: I've now written the promised article. You can read it here. And you can click here to see the previous HotWhopper article on the subject.
Update: The devastating rebuttal is out (archived here). It is, as expected, not devastating at all, unless you were under the mistaken impression that Bob Tisdale understood climate models and global warming. If that were the case - be devastated. It's not a rebuttal either. All it is is Bob Tisdale missing the point and contradicting himself a few times in the process. He seems to think that the authors are dividing models into "good" and "bad". By my reading, he's missing the point. What the authors were doing is providing further evidence that the so-called "pause" is the result of natural variation (see below).
Anthony's own promised rebuttal hasn't appeared. I wonder if he was hoping that Bob Tisdale would let him appear as joint author? You can read the archived WUWT article here if you want to. I've got other things to do so won't be able to rebut Bob's rebuttal for a while yet (see PS below).
While I'm away, if anyone can send me a copy of the paper I'd be grateful (sou at hotwhopper.com). I've emailed the authors, which is a bit hit and miss and/or it may be a while before they see my request. Got it now, thanks.
We're waiting for pseudo-science journalist Anthony Watts to write his "denier-blog-peer-reviewed" rebuttal to the new Risbey & co paper, describing the fatal blunder they think they've discovered. In the meantime, here is what looks to be the essence of the paper as described by Stephan Lewandowsky. (I'm not as clever as Anthony Watts and Bob Tisdale because I don't have a clue what the fatal blunder could be.)
First the abstract to the paper in Nature Climate Change (my paras):
The question of how climate model projections have tracked the actual evolution of global mean surface air temperature is important in establishing the credibility of their projections. Some studies and the IPCC Fifth Assessment Report suggest that the recent 15-year period (1998–2012) provides evidence that models are overestimating current temperature evolution. Such comparisons are not evidence against model trends because they represent only one realization where the decadal natural variability component of the model climate is generally not in phase with observations.
We present a more appropriate test of models where only those models with natural variability (represented by El Niño/Southern Oscillation) largely in phase with observations are selected from multi-model ensembles for comparison with observations. These tests show that climate models have provided good estimates of 15-year trends, including for recent periods and for Pacific spatial trend patterns.
Stephan described how in order to compare models to observations, they "must be brought into phase with the oceans. In particular, the models must be synchronized with El Niño – La Niña". He described three approaches to doing this, which have already been published, including one that I've written about here. He then goes on to describe this new analysis:
The fourth approach was used in a paper by James Risbey, myself, and colleagues from CSIRO in Australia and at Harvard which appeared in Nature Climate Change today.
This new approach did not specify any of the observed outcomes and left the existing model projections from the CMIP5 ensemble untouched. Instead, we select only those climate models (or model runs) that happened to be synchronized with the observed El Niño - La Niña preference in any given 15-year period. In other words, we selected those models whose projected internal natural variability happened to coincide with the state of the Earth’s oceans at any given point since the 1950’s. We then looked at the models’ predicted global mean surface temperature for the same time period.
For comparison, we also looked at output from those models that were furthest from the observed El Niño - La Niña trends.
The results are shown in the figure below, showing the Cowtan and Way data (in red) against model output (they don't differ qualitatively for the other temperature data sets):
Stephan posted these charts - click to see them enlarged:
The data represent decadal trends within overlapping 15-year windows that are centered on the plotted year. The left panel shows the models (in blue) whose internal natural variability was maximally synchronized with the Earth’s oceans at any point, whereas the right panel shows the models (in gray) that were maximally out of phase with the Earth.
The conclusion is fairly obvious: When the models are synchronized with the oceans, they do a great job. Not only do they reproduce global warming trends during the last 50 years, as shown in the figure, but they also handle the spatial pattern of sea surface temperatures (the figure for that is available in the article).
In sum, we now have four converging lines of evidence that highlight the predictive power of climate models.
You can read Stephan Lewandowsky's full article here - it's worth it.
Now what problems Anthony Watts and Bob Tisdale think they have found is still a mystery, which we will unravel in due course. I can't fathom what it could be.
I wonder if they both think that all climate models should mimic natural variability in synchronisation with what is observed? That would be an unrealistic expectation, though it would be nice to have. It would also suggest that they don't understand climate models. My favourite description of models is provided by Scott K. Johnson at Ars Technica.
I'll add to this article once Anthony has written his devastating rebuttal :) Meanwhile, try to get your head around what Anthony finds "of interest". His brain is positively addled with conspiratorial ideation. He added this to his earlier article, where the paper describes the contributions from the various authors:
of interest is this:
J.S.R. and S.L. conceived the study and initial experimental design. All authors contributed to experiment design and interpretation. S.L. provided analysis of models and observations. C.L. and D.P.M. analysed Niño3.4 in models. J.S.R. wrote the paper and all authors edited the text.
And this will amuse:
The rebuttal will be posted here shortly.
PS I've now got
Sou 11:24 am AEST 21 July 2014
James S. Risbey, Stephan Lewandowsky, Clothilde Langlais, Didier P. Monselesan, Terence J. O’Kane & Naomi Oreskes. "Well-estimated global surface warming in climate projections selected for ENSO phase." Nature Climate Change (2014) doi:10.1038/nclimate2310