This was directed at me from a gent over at the skepticforum.com:
"I'd rather like you to discuss the substance of Christy's assertions. Again, specifically, what assertion does he make, regarding AGW, that you classify as "political pronouncement" and dispute? What scientific assertion does he make that you dispute, and why do you dispute it?"I gave a detailed reply:
This post is already too long, so my Christy quotes are very short but they all come from the same source for easy reference. Since "my pronouncements" don't have much weight, I'll defer to the scientists. Although this was in response to a “sceptical” challenge, I imagine it’ll be ignored, or they’ll find a typo, or the length, to ridicule and call it good.
Therefore, this was actually written for those wanting to learn, who are willing to take the energy to look up the links and actually read and think about what the record has to offer.
Knowledge don’t come easy.
US House Ways and Means Committee
Written Testimony ~ 25 February 2009
John R. Christy, University of Alabama in Huntsville
ChristyJR_WM_Written_090225.pdf
The download pdf doesn’t work, but “Quick View” does
The first page is filled with politicking, for instance what in the world does a quote like this have to do with a discussion of climate science?
Energy and Life ~
"We utilize energy from carbon, not because we are bad people, but because it is the affordable foundation on which the profound improvements in our standard of living have been achieved.”
On page 2 he lobbies against California’s gas mileage rules.
The worst part is its extreme one sidedness and ignore-ance of all contra-indicators.
To be clear John Christy has added to the science of atmospheric modeling, but he has undercut his credibility by making claims far exceeding his data and by ignoring findings that disagree with his arguments. Then he sins by distorting his testimony for a purely political agenda.
Furthermore, the fact that he allowed serious errors at his UAH database to continue uncorrected for years, (nor does he do anything to correct this misconception that continues circulating through the AGWHoaxer's echo-chamber), does not reflect too well on him either.
~ ~ ~ ~ ~ ~ ~
page 3~ ~ ~ ~ ~ ~ ~
Overstated warming in current climate models ~
“... in the real world – the world of observations from satellites...”
poor representation of clouds in models {...} have significantly overshot what has actually happened..."
"... enough cooling to offset a significant amount of human-caused global warming...”
That's not what you'll hear from other climate scientists, SkepticalScience has a long list of evidence.
“Dessler (2010) used cloud measurements over the entire planet by the Clouds and the Earth’s Radiant Energy System (CERES) satellite instruments from March 2000 to February 2010 to attempt to determine the cloud feedback. Dessler concluded that although a very small negative feedback (cooling) could not be ruled out, the overall short-term global cloud feedback is probably positive (warming), and may be strongly positive...”
The dynamics of clouds and how they effect GCM results is an area of intense study and from what scientists have learned one that deserves a much more nuanced public explanation, rather than being morphed it into a dishonest political bludgeon.
A Cloudy Outlook for Low Climate Sensitivity
Stowasser et al.(2006)
Chang and Coakley (2007)
Eitzen et al. (2008)
Clement et al. (2009)
A Positive Outlook For Clouds
An Even Cloudier Outlook for Low Climate Sensitivity
~ ~ ~ ~ ~ ~ ~
Figure 2 projections made in 1988 of rapid temperature rises {...} assumed high sensitivity to CO2, overshot the actual temperature trend by a significant amount.~ ~ ~ ~ ~ ~ ~
This is at odds with what other studies are indicating.
Atmoz: Christy’s Nobel Moment Revisited
“. . . At the beginning of this paragraph (Christy) says that climate is too complex to understand, and then in the the same paragraph he disputes the theory using one number. Either the climate is complex or it isn’t. But if it is, then you can’t use one number to disprove global warming. . .”
“. . . Notice that the rates of changes in the troposphere and below are all relatively the same value. The RSS group has higher trend values {...} but they are obviously the same order of magnitude. So we have these two disparate viewpoints. One from Dr. Hansen (GISS) who from his organizations observations (GISTEMP) and modelling work conclude that there is extreme global warming and one from Dr. Christy (UAH) who from his observations (UAH MSU temp) concludes that there is no global warming. Given the extreme similarity in the temperature trend numbers, how do the two groups come to such differing conclusions?. . .”
Satellite measurements of warming in the troposphere
Also see Underestimate of variability in McKitrick et al
~ ~ ~ ~ ~ ~ ~
Figure 3 most recent set of climate models is not faring any better.~ ~ ~ ~ ~ ~ ~
This is simply a false statement - a review of the data does not support it.
For an excellent primer see "Yale Forum on Climate Change and Media"
Fact File
Common Climate Misconceptions
Modeling the Climate
By Zeke Hausfather | January 3, 2008
“Few climate change topics arouse more passion than the seemingly dry field of climate modeling. . .”
SkepticalScience.com also has a number of articles looking at this question in depth
Models Are Unreliable.
Does model uncertainty exaggerate global warming projections?
Over at RealClimate.org where real climate modelers dialogue you’ll find a number of informative papers, just type ‘models’ into their search engine.
~ ~ ~ ~ ~ ~ ~
“... Overstated warming in surface temperature datasets...”~ ~ ~ ~ ~ ~ ~
&
“... a few popular stations for which the data are easy to find, leads to too much warming when the averages are constructed...”
&
page 4
“... data sets based on a few popular stations overstate the warming by up to a factor of three.
&
“... the current, popular land-based {...} overstate the actual warming of the basic atmosphere. (Christy 2001, Christy et al. 2006, Christy et al. 2007, Pielke et al. 2007, Christy et al 2009)...”
Again, doing a search finds many more legitimate sources (as opposed to the echo-chamber that avoids science in favor of agenda driven rhetoric and emotionalism.) pointing out the flaws in Christy's assessment, and reflecting a much different reality than Christy et al. offers.
Are surface temperature records reliable?
"... Similar results can be obtained using different software and methods...
"... Over the past year, there has been quite a flurry of "do-it-yourself" temperature reconstructions by independent analysts, using either land-only or combined land-ocean data. In addition to the previously-mentioned work by Ron Broberg and Clear Climate Code, these include the following:
• Nick Stokes
Updating GHCN Stations Aren't Dying
Monitoring global temperatures
Reduction of station numbers in GHCN
Temperature Data Collection
• Zeke Hausfather
Comparing Global Land/Ocean Reconstructions
• Joseph at Residual Analysis
GHCN Processor
• Chad Herman
Better Late Than Never
• JeffId and RomanM
Roman’s Temperature Reconstruction: Higher trends than HadCRUT
• Tamino
Global Update
(There are probably others as well that we're omitting!)
Most recently, the Muir Russell investigation in the UK was able to write their own software for global temperature analysis in a couple of days.
For all of these cases, the results are generally quite close to the "official" results from NASA GISS, CRU, and NOAA NCDC. Figure 3 shows a collection of seven land-only reconstructions, and Figure 4 shows five global (land-ocean) reconstructions.
A Graph
~ ~ ~ ~ ~ ~ ~
Figure 4 shows the very different impact of surface development on daytime and night time temperatures in the example from Central California {...} which is then erroneously attributed to the effects of increased CO2 concentrations.(Christy et al. 2006, 2009).~ ~ ~ ~ ~ ~ ~
This is another example of Christy reporting only selected factors that support C’s position and ignoring pieces to the puzzle that are inconvenient to C’s thesis:
Bonfils, C., P. Duffy, and D. Lobell (2007b), Comments on “Methodology and results of calculating central California surface temperature trends: Evidence of human-induced climate change? by J. R. Christy et al., J. Clim., 20, 4486-4489.
“Understanding the causes of observed regional temperature trends is essential to projecting the human influences on climate, and the societal impacts of these influences. In their recent study, Christy et al. (2006, hereafter CRNG06) hypothesized that the presence of irrigated soils is responsible for the rapid warming of summer nights occurring in California’s Central Valley over the last century (1910–2003), an assumption that rules out any significant effect due to increased greenhouse gases, urbanization, or other factors in this region. Their interpretation is based on an apparent contrast in summer nighttime temperature trends between the San Joaquin Valley (+0.3 ± 0.1°C decade−1) and the adjacent western slopes of the Sierra Nevada (−0.25 ± 0.15°C decade−1).
Here, we question the interpretation of the difference in temperature trends between the valley and the Sierra Mountains (and other regions of California), as well as the amplitude, sign, and uncertainty of the Sierra nighttime temperature trend itself. . .” read on
~ ~ ~ ~ ~ ~ ~
Regarding Christy’s basic simplistic claim that correlation between CO2 and global temperatures is poor, agwobserver.wordpress.com has a long list of studies on the topic, that in sum total do find correlation between CO2 and temperatures.
“Here is a list of papers on the correlation between carbon dioxide concentration and temperature. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.”
also: “... However, the long-term causality shows that the rise in GST during the last decades can be explained only if the anthropogenic factor (CO2) is taken into account in a model.”
Exploring Granger causality between global average observed time series of carbon dioxide and temperature – Kodra et al. (2010)
From Granger causality to long-term causality: Application to climatic data – Smirnov & Mokhov (2009)
Correlation Analysis between Global Temperature Anomaly and two main factors (CO2 and an index) – Moon (2008)
Assessing causality from multivariate time series – Verdes (2005)
with many more listed read on. . .
~ ~ ~ ~ ~ ~ ~
Finishing his testimony Christy degenerates back into political evangelizing ...
It is fair to ask: is the man a scientists, or is he a political animal and “free market" lobbyist?
“Energy and Life~ ~ ~ ~ ~ ~ ~
Finally, we utilize energy from carbon not because we are bad people, but because it is the affordable foundation on which profound improvements in our standard of living have been achieved – our health and our welfare.
...without energy life is brutal and short.
The message here is that if energy costs rise, the price the American economy will pay, especially the poorest among us, will be high – yet there will be virtually no impact on emissions or climate...”
There is also the matter of significant errors in Christy’s own UAH database, the same database that years worth of AGW deniers have and continue to tout as proving global warming is not a problem:
Yale Climate and Media Forum does a good job of explaining the details.
". . . The UAH team pioneered the approach in 1979, combining temperature measurements from multiple satellites to produce an estimate for monthly global mean temperatures. UAH published data showing significantly lower tropospheric cooling from 1979 till 1998, contradicting the warming trend observed by the surface stations. . . read on
Real Climate.org does a nice job of dissecting the details for us.
“... In the first Science Express paper, Mears et al produce a new assessment of the MSU 2LT record and show that one of the corrections applied to the UAH MSU 2LT record had been applied incorrectly, significantly underplaying the trend in the data. This mistake has been acknowledged by the UAH team who have already updated their data (version 5.2) so that it includes the fix. This correction (related to the drift in crossing times at the equator) mainly affects the tropics, and was most important for one particular satellite (NOAA-11).
"Interestingly, Fu and Johansen (2005) singled out this same satellite and this same correction as being the source of divergence between the different records, though without being able to say exactly what the problem was. The fix leads to an increase of about 50% in the UAH global mean trend (0.086 to 0.12 deg/decade). The new RSS version of the 2LT record still shows a higher trend (0.19 deg/decade), with the difference being due to the methodology used to splice the different satellites...”
“... It will not have escaped the notice of keen observers that the satellite/model discrepancy has been used extensively in certain circles to cast doubt on the models, surface temperature record and our understanding of basic physics. Some recent examples for instance, used the UAH 2LT record absolutely uncritically (despite the fact that there have been many previous revisions, and that other analyses give very different results)...”
~~~~~~~~~~~
Finally, this Climate Progress write up regarding a 12/9/09 CNN’s Wolf Blitzer interview with John Christy and Gavin Schmidt offers some excellent closing thoughts:
Earth to John Christy: Misleading for free is wrong, too.
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