Guest post by Bob Tisdale
INTRODUCTION
Chapter 4-7 of If the IPCC was Selling Manmade Global Warming as a Product, Would the FTC Stop their deceptive Ads? included comparisons of the CRUTEM3 Land Surface Temperature anomalies to the multi-model mean of the CMIP3 climate models. For those who have purchased the book, see page 99. As you will recall, CMIP3 stands for Phase 3 of the Coupled Model Intercomparison Project, and CMIP3 served as the source of the climate models used by the Intergovernmental Panel on Climate Change (IPCC) for their 4th Assessment Report (AR4). CRUTEM3 is the land surface temperature data available from the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia.
This post compares the new and improved CRUTEM4 land surface temperature anomaly data to the same CMIP3 multi-model mean. CRUTEM4 data was documented by the 2012 Jones et al paper Hemispheric and large-scale land surface air temperature variations: An extensive revision and an update to 2010. I’ve used the annual time-series data, specifically the data in the second column here, changing the base years for anomalies to 1901 to 1950 to be consistent with Figure 9.5 of the IPCC’s AR4.
And, as I had with the other 20th Century Model-Observations comparisons, the two datasets are broken down into the 4 periods that are acknowledged by the IPCC in AR4. These include the early “flat temperature” period from 1901 to 1917, the early warming period from 1917 to 1938, the mid-20th Century ‘flat temperature” period from 1938 to 1976, and the late warming period. The late warming period in the chapter 4-7 comparisons in If the IPCC was Selling Manmade Global Warming as a Product, Would the FTC Stop their deceptive Ads? ended in 2000. For the late warming period comparisons in this post, I’ve extended the model and CRUTEM4 data to 2010.
COMPARISONS
As shown in Figure 1, and as one would expect, the models do a good job of simulating the rate at which the CRUTEM4-based global land surface temperatures rose during the late warming period of 1976 to 2010.
Figure 1
But like CRUTEM3 data, that’s the only period when the IPCC’s climate models came close to matching the CRUTEM4-based observed linear trends.
According to the CMIP3 multi-model mean, land surface temperatures should have warmed at a rate of 0.043 deg C per decade from 1938 to 1976, but according to the CRUTEM4 data, global land surface temperature anomalies cooled at a rate of -0.05 deg C per decade, as shown in Figure 2.
Figure 2
Figure 3 compares the models to the global CRUTEM4 data during the early warming period of 1917 to 1938. The observed rate at which global land surface temperatures warmed is almost 5 times faster than simulated by the IPCC’s climate models. 5 times faster.
Figure 3
And in Figure 4, the models are shown to be unable to simulate the very slow rate at which land surface temperatures warmed during the early “flat temperature” period.
Figure 4
According to the models, the linear trend of the global land surface temperatures during the late warming period should be 6.6 times higher than during the early warming period. See Figure 5.
Figure 5
Yet according to the new and improved CRUTEM4 land surface temperature data, Figure 6, the land surface temperatures warmed during the late warming period at a rate that was only 40% higher than during the early warming period.
Figure 6
CLOSING
The models show no skill at being able to simulate the rates at which global land surface temperatures warmed and cooled over the period of 1901 to 2010. Why should we have any confidence in their being able to project global land surface temperatures into the future?
ABOUT: Bob Tisdale – Climate Observations
ebook (pdf and Kindle formats): If the IPCC was Selling Manmade Global Warming as a Product, Would the FTC Stop their deceptive Ads?
SOURCES
The CMIP3 multi-model mean data is available through the KNMI Climate Explorer
http://climexp.knmi.nl/selectfield_co2.cgi?id=someone@somewhere
And as noted in the post, the annual CRUTEM4 data is available through the Met Office website:
http://www.metoffice.gov.uk/hadobs/crutem4/data/diagnostics/global/nh+sh/index.html
Specifically:
http://www.metoffice.gov.uk/hadobs/crutem4/data/diagnostics/global/nh+sh/global_n+s
Me thinks these people are simply masturbating the data in a corner ignoring the reality of reality and the foolishness of this unscientific modeling garbage.
Interesting first analysis Bob, however one think I think is dubious:
” These include the early “flat temperature” period from 1901 to 1917, the early warming period from 1917 to 1938″
Are you sure these are “4 periods that are acknowledged by the IPCC in AR4. ” ?
I don’t recall IPCC mentioning such precise dates. I think that is false attribution. It’s also cherry picking. Trough to peak period for calculating a linear trend. very naughty. If you went from 1915 to 1940 the result would not be quite the same, would it?
I am strongly critical of this sort of mis-representation by warmists and I’m not going to say I like it any more when you do it.
The forced response will show up in all model ensembles, so will be reinforced by the averaging involved in making the multi-model mean. Contributions to the global average temperature from internal variability will appear in various instances within an ensemble, but may not occur at the same time or to the same degree, so the process of averaging will reduce the contribution of internal variability.
The post 1975 warming is hypothesised to be a forced response to anthropogenic forcing. The earlier periods of warming do not show a similar global pattern. That the post 1975 warming shows up robustly in the ensemble mean supports the hypothesis that it is a forced response. That the preceding changes do not suggests they are not predominatly forced responses but are mainly due to internal variability.
It seems every day that some “official” agency is changing the data to suit the propaganda message. Is “science” now dead in the modern era?
I wish people would stop calling it ,”the rate of temperature change”
PLEASE can we use the proper terminology, “the rate of temperature manipulation”
I 2nd, 3rd and 4th, the sentiment below…
Louis Hooffstetter says:
March 20, 2012 at 1:05 pm
Steve Mosher says…
Steve: I enjoy your posts, primarily because you’re a straight shooter and also because I learn from them (although the details can be slightly over my head). I think most of us agree with Juaj V. who says “Models are laboriously tuned to match the latest warm AMO period. Period.” and johnmcguire who says “I am weary of the constant adjustment to exsisting data in order to make it fit the false models.”
What’s your opinion on the constant ‘tuning’ of the models & ‘adjusting’ of the data until they finally match?
Dr Burns says:
March 20, 2012 at 1:17 pm
Most importantly Hadcrut4 does away with Jonesy’s most embarrassing admission to parliament that there’s been no warming for the past 15 years.
I hope Hadcrut4 will be on woodfortrees soon. But in the meantime, RSS still shows no warming for 15 years and 3 months.
http://www.woodfortrees.org/plot/rss/from:1995/plot/rss/from:1996.9/trend
P.S. There are at least 3 different versions of Hadcrut3 and the one on woodfortrees right now is apparently NOT the one being adjusted. I wonder if that will still be around after Hadcrut4 is out. They deleted the January anomaly of 0.218 and the February one is not up yet. I wonder if we will ever see it.
I find it interesting (and suspicious) that a model temperature trend of the Earth and samples supposedly taken from the earth (without benefit of geostatistical interpolation to represent the volume of the Earth) match so gloriously well. I’ve never seen such a phenomenal (and most unlikely) correlation.
Consider the corrollary question: Is the model a sample-generating scheme? No?
Bob Tisdale – Curious; you don’t seem to have shown the range of model variations around your model mean (unlike http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-9-5.html and also http://www.realclimate.org/index.php/archives/2012/02/2011-updates-to-model-data-comparisons/).
Given that the temperature record falls within the range of variation of those models, your depiction here is a wee bit unfair.
[Steven Mosher says:
March 20, 2012 at 11:37 am
Did you MASK the output of the models to match the spatial coverage of the observations?
For example: in the early part of the record the entire globe is NOT sampled. So the average has some spatial bias in it. If you used the complete model output to come of with the average for this period, then you are doing the comparison wrong. First, you have to extract the MONTHLY observation mask from the observation dataset. That will tell you which GRIDS there are samples for. Since CRU do NOT interpolate or extrapolate U must extract this data.]
If this is enough to make a difference then there is no meaning in graphing the CRUTEM data at all. It would be like (this is of course an exaggeration) graphing Europe’s temp in 1910 then Asia’s temp in 1920 then North America’s in 1930. I.e. You’re graphing different measurements at different dates thus the composite graph has no meaning what so ever. Thus any trends drawn from it also have no meaning. Is that what you really intended to imply?
On the other hand if the differences in what is being measured is sufficiently small to draw trends etc. then I can’t see that it would make a noticible difference in Mr. Tisdale’s analysis.
“Bob, How does this ‘HalfCut 2.0’ performance using ‘CUT-EM-UP4’ data compare to Olympic performance using ‘HadCuT3’ data?” (<– fake quotes)
[I had a funny feeling people would ask Too]
JK
Sorry Bob, I know you were waiting for a question like this your entire life. 😉
Bloke down the pub says (March 20, 2012 at 12:13 pm)
Did they really think that no-one would notice that they had their thumb on the scales?
———————————–
Or the large checkout lady who had her breasts on the scales when charging for fruit! 🙂
Are you sure CMIP3 isn’t really CHIMP3 ??
johnmcguire says:
March 20, 2012 at 12:07 pm
I see that you, too, have discovered that Mosher has no instinct for raw data but is bustling with energy for endless adjustments to the statistics. Mosher, would you mind telling us in what way raw data finally snaps the leash and calls statistics to heel? Or is that impossible in your universe?
Steven Mosher says:
March 20, 2012 at 11:37 am
Did you MASK the output of the models to match the spatial coverage of the observations?
Did the the models used in the multimodel mean have their observations MASKED so they have the same coverage?
And, as you pointed out, spacial coverage in the early data was sparse and non uniform. So it’s basically worthless from a global standpoint. Hence there is no way anyone can validate whether the models on a global scale were valid during the early part of the last century.
KR says: “Bob Tisdale – Curious; you don’t seem to have shown the range of model variations around your model mean …Given that the temperature record falls within the range of variation of those models, your depiction here is a wee bit unfair.”
Unfair? I don’t believe anyone has ever before said my data presentations were unfair. Consider yourself a first.
Refer to the discussion here, under the heading of CLARIFICATION ON THE USE OF THE MODEL MEAN:
http://bobtisdale.wordpress.com/2011/12/12/part-2-do-observations-and-climate-models-confirm-or-contradict-the-hypothesis-of-anthropogenic-global-warming/
Which models are predicting new record high temps? Highs like the current record-breaking run in the US? In International Falls, which threatened suit when a Colorado city tried to steal its “Nation’s Icebox” moniker, the mercury went to 77 degrees on Saturday — which was 42 degrees above average, and 22 degrees above the old record.
Most climate models predict rising temps. Looks like they’re on the money!
P. Solar says: “Are you sure these are ‘4 periods that are acknowledged by the IPCC in AR4. ‘?”
The IPCC clearly states that there are two level temperature periods and two warming periods during the 20th Century. Refer to Chapter 3 Observations: Surface and Atmospheric Climate Change.
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter3.pdf
Under the heading of “3.2.2.5 Consistency between Land and Ocean Surface Temperature Changes”, the IPCC states with respect to the surface temperature variations over the period of 1901 to 2005 (page 235):
“Clearly, the changes are not linear and can also be characterized as level prior to about 1915, a warming to about 1945, leveling out or even a slight decrease until the 1970s, and a fairly linear upward trend since then (Figure 3.6 and FAQ 3.1).”
The years and approximations listed by the IPCC are for global land plus sea surface temperature data. They vary slightly if land or sea surface temperatures are presented separately.
Gillian, I hope you are being sarcastic – except for North America, temperatures during this winter in the Northern Hemisphere were below normal.
So what happened to your computers?
REPLY: I took them back to my office, repaired them to demo another day – Anthony
Barry,
Everyone knows that the data from the early part of the century are even more worthless than the data available for the following years, up to the satellite era. But for momentous policy decisions we need something to go on, so we just pretend that it is sufficient for the purpose.
Not yours! I meant Bob’s!!! From the confiscation! I’ve been dying to find out what happened to his computers after they were carted off to the Secret Service, or CIA, or was that the batcave? 007’s boss?
For KR and Mosher, you both need to be more clear about the obfuscations you are attempting.
Hadcrut3 and GISS and the NCDC are right now lower the lowest runs in the 23 models used in IPCC AR4. Hadcrut4 looks like it will not be more than 0.1C higher than Hadcrut3, so yeah, FAIL again.
http://img99.imageshack.us/img99/5937/ipccmodelspreadvshc3jan.png
http://img818.imageshack.us/img818/3300/ipccspreadhindforecast2.png
Of course, the lower troposphere satellite temps are off the charts below.
http://img827.imageshack.us/img827/8535/ipccforecastsobsfeb2012.png
An interesting reminder, and the only precedent I am aware of, where citizens (“sceptics”) took the Crown Research Institute, NIWA, to court over their updated adjustments. They eventually abandoned their adjustments and the country was apparently .7C cooler as a result.
http://www.scoop.co.nz/stories/SC1012/S00054/climate-science-coalition-vindicated.htm
Philip Finck says:
March 20, 2012 at 11:41 am
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Philip
The new Crutem4 which has been revised so that it is warmer than the earlier Crutem3 version at any rate warmer from the 1970s onwards does now show an accelerated rate of warming.
The 1920 to 1940 warming is now 0.2degC per decade, whereas the 1980 to 2000 warming is 0.28degC per decade.
This new upwardly revised data set (which also cools earlier periods) therefore overcomes one of the most significant arguments that sceptics use to have, namely where is the CO2 signature when the rate of warming between 1980 to 2000 (when manmade CO2 levels were rising and said to be significant) is no greater than the rate of warming bewteen 1920 to 1940 (when manmade CO2 was not a significant factor)? Crytem4 now allows then to say the rate of warming has increased by some 40% up from 0.2 degC per decade to 0.28 degC per decade. It is up by some 40% due to CO2.