The Forum > Article Comments > Arguing about models and observations, with respect to global warming > Comments
Arguing about models and observations, with respect to global warming : Comments
By Don Aitkin, published 21/10/2013If the climate of our planet is technically 'chaotic', meaning that elements of it are unpredictable, then modelling it is bound to have have some inaccurate results, to say the least.
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Posted by cohenite, Tuesday, 29 October 2013 2:11:20 PM
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Oh Anthony, will you ever learn to read? My complaint about Spencer’s graph was that he used a base period that was likely to minimise temperature increase for the UAH data set for the lower troposphere. You correct this complaint by showing a graph for the tropical mid-troposphere that uses exactly the same base period? It is not only for a different bit of the atmosphere, it is for the tropics only and it uses the same base period. So as a correction it is completely useless.
You next mistake the problem of stratosphere bleeding into the mid-troposphere models of UAH data. This tends to make the modelled satellite data too cool, so of course they will fall below the mean of climate models. I thought everyone in climate science knew about this problem. As for Brozek’s analysis, I have already explained why it was cherry picked. If you want to test a hypothesis of no warming for 15 years, you test over a 15 year period, not 9 years, not 12 years, not 13 years and not 16 years. That is why Brozek’s analysis is embarrassingly wrong. Posted by Agronomist, Wednesday, 30 October 2013 2:06:33 PM
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The graph for this article begins in 1983; the graph I showed begins in 1979; both use 5 year running means; a running mean is NOT a base period. Why would Spencer use a 5 year running mean? Does a 5 year running mean advantage or disadvantage, that is produce bias, for or against AGW?
A running mean after 1976-78, when the step up in temperature occurred would not be biased in any respect because the heating produced by the Climate Shift is already in the system. In any event the graph in this article begins its running mean in 1983 not 1979. As for cooling from the lower Stratosphere "bleeding' into the Troposphere that is nonsense as Fu has showed: http://joannenova.com.au/2012/05/models-get-the-core-assumptions-wrong-the-hot-spot-is-missing/ As for the Mears and Wentz of RSS and Christy and Spencer of UAH debate see here: http://marshall.org/climate-change/some-convergence-of-global-warming-estimates/ And here: http://www.gfdl.noaa.gov/blog/isaac-held/2012/01/01/21-temperature-trends-msu-vs-an-atmospheric-model/ And here: http://www.worldclimatereport.com/index.php/2004/05/04/assault-from-above/ At the end of the day there is no THS and the surface temperature contradicts the models; see Stockwell: http://wattsupwiththat.com/2011/04/13/stockwell-asks-is-the-atmosphere-still-warming/ And Tisdale: http://wattsupwiththat.com/2013/10/29/ipcc-adjusts-model-predicted-near-term-warming-downwards/ Posted by cohenite, Wednesday, 30 October 2013 5:51:53 PM
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Oh dear Anthony, you are still struggling with this. I know math is hard, but this is deceptively easy. Have a look at the Y-axis on those graphs (that is the one going up and down). The units are in temperature anomaly from baseline – yes I know Spencer has left them off one of the graphs, but that is what they are. In both graphs the baseline is the average of 1979 to 1983.
In the graph that starts in 1979 all Spencer has done is change from a 5-year end moving average (1979-1983 period is averaged at 1983), to a 5-year beginning moving average (1979-1983 period is averaged at 1979). He should use a centred moving average, but that is another discussion. That article you link to by yourself and Jo Nova does not address the issue of stratospheric cooling and its effects on satellite data at all. It is not even mentioned. However, the link you give to the NOAA does: “These trend are smaller than the T2LT trends, in both the model and the observations, despite the fact that T2 weights the lower troposphere less strongly that T2LT. The model trends actually increase with height through the troposphere. The problem, long appreciated, is that T2 has significant weight in the stratosphere, where there is a cooling trend in both model and observations…” Posted by Agronomist, Friday, 1 November 2013 8:24:03 AM
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I also talk about the THS in respect of that 'corrected' Troposphere graph. IE. that is, the Tropical mid Troposphere.
The lack of Troposphere warming anywhere, at any level, contrary to the model predictions is a done deal.
As for surface temperatures and your disproof of Brozek's analysis. You still ignore what Brozek did. What he did was start at the furthest negative slope in each temperature indice.
Now, you're obviously a smart guy Agro, your arrogance clearly shows that, despite your troll tendencies; answer this, what does starting at a negative point, actually the month after the furthest negative slope, mean for the following anomalies?
If you're as smart as you condescend to be you'll know that is a more accurate way of presenting anomaly trends then based on a selected year or time span and applying OLS? Why? You should know, it has to do with favourite complaint against Spencer, base period selection.