All the blogosphere is abuzz with Advancing decadal-scale climate prediction in the North Atlantic sector. I don’t have much to say that JA hasn’t already said. But that isn’t going to stop me saying it.
Firstly they’ve done something very odd with the reference model data in fig 4. The std IPCC projections would be right on their obs verification (which stops in 1998 for some bizarre reason) and their “forecast” would be even more obviously an outlier. I assume that the black line on fig 4 must be their own model. Looking again, I’m really rather baffled how this can possibly be anything useful, because their model so obviously goes wrong after 1995.
Secondly, the Torygraph quotes them as saying Noel Keenlyside of the Leibniz Institute of Marine Sciences, Kiel, Germany, said: “The IPCC would predict a 0.3Â°C warming over the next decade. Our prediction is that there will be no warming until 2015 but it will pick up after that.” No, thats not what the IPCC “predicts”, and no, no-warming is not what your own model predicts. Just look at your own figure 4, you dolt. It quite clearly shows warming from 2005 to 2015.
Maybe we should read their own press release, entitled “Improved climate predictions suggest a reduced warming trend during the next 10 years” to which the obvious rejoinder is “in what sense, improved?” – in the sense that it got them into Nature? They say To date climate change projections, as published in the last IPCC report, only considered changes in future atmospheric composition. This strategy is appropriate for long-term changes in climate such as predictions for the end of the century. However, in order to predict short-term developments over the next decade, models need additional information on natural climate variations, in particular associated with ocean currents
Whats weird here is there total lack of reference to Smith et al. Or maybe it isn’t so surprising. Smith et al have already done what they’ve done, except better. Mind you, it was published in Science, and the me-too effect may account for why this has got into Nature. Presumably the passing reference to assimilating ocean currents justifies their novelty; otherwsie they would have mentioned SSTs.
They go on The improved predictions suggest that global warming will weaken slightly during the following 10 years but their own figure 4 shows no such thing! (but its better than the no-warming-till-2015 junk that the lead author is quoted as saying). Connect the dots from 2005-2015 and you end up with 0.2 oC/decade, which is fairly standard. Maybe the annual data shows different, but they don’t show that. Why are people lapping this stuff up without even comparing the words to the figures?
Conclusion: this appears to be a mildly interesting study, which may have some slight novelty although not much. But it looks to me like the obvious model flaws mean that it doesn’t tell you anything useful about the real world, and it shouldn’t be getting the publicity that it is.
[Update: well, it made R4 at 10 o’clock. They had that David King on. Sigh. Fairly clear that he’d read the press release but not the paper, and fell into the obvious holes -W]