|Shag on Rock|
Apologies to Josh
This idea has been around for yonks.
Cohenite looked at the idea in 2008. Basically the technique is detrend for all natural factors by removing the estimate of their temperature effect and what is left should be the pure AGW signal.
Lots of people have done this; the original paper was Keenlyside et al in 2008. Easterling and Wehner in 2009 extended this concept to the usual grotesque AGW exaggeration. The previous Keenlyside et al effort predicted masking of underlying AGW due to SST driven natural variation. Unfortunately, when the ENSO is removed from temperature trends there is no post 2000 underlying AGW. Easterling and Wehner revisit this trainwreck of an idea to prove that future cooling will still have underlying AGW. Their null hypothesis [NH] really settles the matter. The NH is that there will be an “equal percentage of statistically significant positive and negative trends” [p6]. This is high order virtual reality; the concept of the 100 year flood explains why. Pacific Decadal Oscillation [PDO] climate phases have greater probability of floods during a negative phase during which time [about 30 years] there may be several 1 in 100 year floods. During the positive, El Nino dominated PDO phase there will most likely be no 1 in 100 year flood.
The same principle applies to temperature. Positive PDOs will have increasing temperature trends and vice-versa for negative PDOs. The paper doesn’t consider ENSO at all apart from an admission that it is not modelled well [p6]. Table 1 shows more positive temperature trends in the 20thC. This was due to positive PDO dominance not, as the paper claims, AGW.
The recent definitive paper on this idea by Foster and Rahmstrof in 2011 supposedly extracted a pure AGW signal after removing all natural factors. F and R are a lot of fun.They removed all the natural factors that may have contributed to temperature increase and were left with a range of 0.014 to 0.018 K yr−1 as the pure AGW forcing. They calculated a rate which was constant from 1979. This should have set the alarm bells ringing for a start since CO2 was increasing exponentially during this period; if the dominant forcing factor was increasing the AGW temperature effect should also have been increasing. But it seems that their methodology was also flawed. By including a linear trend for warming in their analysis as an independent variable, Foster and Rahmstorf have demonstrated that global warming is well correlated with global warming. Furthermore Bob Tisdale shows Forster and Ramstorf were wrong to consider ENSO as an exogenous factor and to exclude it from their analysis.
Just when you think this nonsense is over along comes Lew. Lew says this:
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.
Credit where credit is due. This is smart. Lew doesn’t remove natural variation he selects models which have natural variation in phase with AGW. AGW is now proved because there is temperature increase when you factor in natural variation.
But seriously this is a dog’s breakfast. What is he saying; that AGW is only to be measured when there is natural warm phase such as in the +ve PDO:
That is AGW is only to be shown when the world is heating through a warm natural phase as shown in the red lines? Is this because natural variation in the cool phase eliminates any AGW signal as shown in the blue lines? And surely in the warm phases of natural variation wouldn’t the warming be especially high if AGW and natural variation are working together?
Desperation and absurdity is now the stock in trade of alarmists like Lewandowsky.
A real scientific paper about Ocean Heat Content [OHC] has just been published by leading oceanographic experts Wunsch and Heimbach. They show that the deep oceans are cooling and that, logically, heat in the ocean probably comes from the bottom of the ocean due to geothermal activity not from the surface down as AGW theory insists in the most ridiculous way [see here and here]. Figure 18 from Wunsch and Heimbach sums up the nonsense about OHC:
That’s it folks; AGW demolished and Lew left like a Shag on a rock.