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Tuesday, September 10, 2013

An independent confirmation of global land warming, not using temperatures from meteorological stations

It has been hypothesized in some scientific publications (e.g., Pielke et al, JGRA, 2007, doi:10.1029/2006JD008229) and sometimes outright asserted (by AGW "skeptics" or in some media outlets; e.g., here, here, and here) that temperature analyses like GISTEMP, HadCRUT, or NCDC were not reliable, and the global warming, seen in these analyses over the last century, using direct temperature measurements from meteorological stations was largely just an artefact of faulty measurements, data adjustments (homogenization), the urban heat island effect, and other factors.

Gilbert P. Compo, Prashant D. Sardeshmukh, Jeffrey S. Whitaker, Philip Brohan, Philip D. Jones, and Chesley McColl have just published a new study (for the abstract: Compo et al., GRL, 2013, doi:10.1002/grl.50425), where the land near surface air temperature is derived using a state-of-the-art data assimilation system (20th Century Reanalysis). The temperature is calculated from other variables (surface pressure) and parameters in the reanalysis. The measured land surface air temperature is not part of the input data. Thus, any possible contamination of the measured land near surface air temperature by other factors than the state of the atmosphere does not have any effect on the land near surface temperatures calculated in the reanalysis system. The correlation between the land near surface temperature, calculated from other variables in the data assimilation system, and the land near surface temperature data series, derived using direct measurements over land is very high. This increases the confidence in that the statistically significant global warming trend of the atmosphere near the surface, seen in the GISTEMP, HadCRUT, or NCDC analyses over the last century is real, and those data sets can be used as reliable references for other scientific analyses.


Wednesday, August 7, 2013

American Geophysical Union's statement on human-induced climate change

The American Geophysical Union (AGU) has revised and reaffirmed its position on climate change caused by human activities, which was adopted for the first time in the year 2003. Position statements like this by the AGU expire after four years, unless it is reaffirmed. I personally agree with this statement. Here, I document the text:

"Human-induced climate change requires urgent action.

Humanity is the major influence on the global climate change observed over the past 50 years. Rapid societal responses can significantly lessen negative outcomes.

'Human activities are changing Earth’s climate. At the global level, atmospheric concentrations of carbon dioxide and other heat-trapping greenhouse gases have increased sharply since the Industrial Revolution. Fossil fuel burning dominates this increase. Human-caused increases in greenhouse gases are responsible for most of the observed global average surface warming of roughly 0.8°C (1.5°F) over the past 140 years. Because natural processes cannot quickly remove some of these gases (notably carbon dioxide) from the atmosphere, our past, present, and future emissions will influence the climate system for millennia.

Extensive, independent observations confirm the reality of global warming. These observations show large-scale increases in air and sea temperatures, sea level, and atmospheric water vapor; they document decreases in the extent of mountain glaciers, snow cover, permafrost, and Arctic sea ice. These changes are broadly consistent with long-understood physics and predictions of how the climate system is expected to respond to human-caused increases in greenhouse gases. The changes are inconsistent with explanations of climate change that rely on known natural influences.

Climate models predict that global temperatures will continue to rise, with the amount of warming primarily determined by the level of emissions. Higher emissions of greenhouse gases will lead to larger warming, and greater risks to society and ecosystems. Some additional warming is unavoidable due to past emissions.

Climate change is not expected to be uniform over space or time. Deforestation, urbanization, and particulate pollution can have complex geographical, seasonal, and longer-term effects on temperature, precipitation, and cloud properties. In addition, human-induced climate change may alter atmospheric circulation, dislocating historical patterns of natural variability and storminess.

In the current climate, weather experienced at a given location or region varies from year to year; in a changing climate, both the nature of that variability and the basic patterns of weather experienced can change, sometimes in counterintuitive ways -- some areas may experience cooling, for instance. This raises no challenge to the reality of human-induced climate change.

Impacts harmful to society, including increased extremes of heat, precipitation, and coastal high water are currently being experienced, and are projected to increase. Other projected outcomes involve threats to public health, water availability, agricultural productivity (particularly in low-latitude developing countries), and coastal infrastructure, though some benefits may be seen at some times and places. Biodiversity loss is expected to accelerate due to both climate change and acidification of the oceans, which is a direct result of increasing carbon dioxide levels.

While important scientific uncertainties remain as to which particular impacts will be experienced where, no uncertainties are known that could make the impacts of climate change inconsequential. Furthermore, surprise outcomes, such as the unexpectedly rapid loss of Arctic summer sea ice, may entail even more dramatic changes than anticipated.

Actions that could diminish the threats posed by climate change to society and ecosystems include substantial emissions cuts to reduce the magnitude of climate change, as well as preparing for changes that are now unavoidable. The community of scientists has responsibilities to improve overall understanding of climate change and its impacts. Improvements will come from pursuing the research needed to understand climate change, working with stakeholders to identify relevant information, and conveying understanding clearly and accurately, both to decision makers and to the general public.'

Adopted by the American Geophysical Union December 2003; Revised and Reaffirmed December 2007, February 2012, August 2013."

Friday, July 12, 2013

Emerging new El Nino?

There has been some interesting development in the equatorial subsurface temperatures in the Pacific for the last two months. The positive temperature anomaly, which has been dominant in the upper 300 meters of the equatorial water body of the Western Pacific has spread eastward. Now we have a positive subsurface anomaly over the whole longitude range from 130E to 100 W. Only the far Eastern Pacific still shows a negative anomaly.

(Source:, pg. 11)

The last model simulations are from June 2013. Most of the models predicted ENSO neutral conditions through 2013 back then.

(Source:, pg. 26)

I am curious what the new model simulations, initialized with updated input data are going to say.

If one looks at the table of cold and warm episodes of ENSO, there has not been any period longer than four years from the end of an El Nino to the start of the following El Nino, going back to the year 1950. We are in the third year since the end of the last El Nino episode now. If it does not happen this year a new El Nino really will be due next year. Otherwise it would be unusual, if none occured compared to the frequency of occurrence for the period between 1950 and present.

Wednesday, July 10, 2013

AGW denier Marc Morano of Climate Depot and CFACT suggests, "global warming skeptics" are defined by fantasies about lynching climate scientists

Besides Morano did not get the facts right with respect to my employment, since I am not a NASA scientist (I am a Columbia University scientist at GISS), why am I saying this? Because Morano asserts on the Climate Depot website, "NASA scientist Jan Perlwitz publicly warns global warming skeptics, 'I shoot you dead'".

The actual fact is that I strongly responded on my own behalf to a lynch fantasy against climate scientists (which came combined with a delusional analogy to Nazi-Germany), articulated by a specific anonymous individual with the alias Allencic who said,

Morano's claim my response to Allencic's lynch fantasy was addressed at "global warming skeptics" is a lie. Thus, when Morano interprets my response to this as a "warning" against "global warming skeptics" in general, he suggests this kind of lynch fantasies against climate scientists was a defining feature of "global warming skeptics". I did not say, and I do not think it was.

Also, by displaying my statement as something condemnable, even though it was a conditional statement for the case the addressed individual really tried to tar, feather and torch me, i.e., murder me, because I was a climate scientist, Morano also suggests that I did not have any right to self-defense in such a situation. Thus, AGW denier Marc Morano, who is paid by the conservative think thank  Committee for a Constructive Tomorrow (CFACT) for spreading his propaganda and lies on his website, implicitly suggests that climate scientists did not have a right to self-defense, when someone tried to murder them.

Marc Morano is an appalling example of lack of ethics and honesty on the side of the AGW deniers.

Statement of Macquarie University regarding the termination of Professor Murry Salby

Yesterday, anti-science blogger Anthony Watts of posted an article, "Professor Murry Salby, who is critical of AGW theory, is being disfranchised, exiled, from academia in Australia", in which Watts claims that Murry Salby was wronged by Macquarie University. The claim is based solely on assertions in an email by Salby to Anthony Watts. I participated in this thread until I got permanently banned, saying that I do not believe Salby's accusations just at face value. The anti-science crowd of "skeptics", being not very skeptical at this point, rushed to the usual judgement, ranting about the evil establishment suppressing "the truth" and punishing critical scientists. In one case the desire of violence against those evil climate scientists who say anthropogenic global warming was real, was articulated.

I think, one should not just listen to what Salby claims, one also should listen what the other side has to say. If Salby was wronged he can and should choose the legal means available to him. But I am not going to assume he was wronged just because he claims so in some email to an AGW denier website.

Macquarie University has released following statement regarding the matter on July 10, 2013, which reads,

"Macquarie University does not normally comment on the circumstances under which employees leave the University. However, we feel in this instance it is necessary to do so in order to correct misinformation.

The decision to terminate Professor Murry Salby’s employment with Macquarie University had nothing to do with his views on climate change nor any other views. The University supports academic freedom of speech and freedom to pursue research interests.

Professor Salby’s employment was terminated firstly, because he did not fulfil his academic obligations, including the obligation to teach. After repeated directions to teach, this matter culminated in his refusal to undertake his teaching duties and he failed to arrive at a class he had been scheduled to take.

The University took this matter very seriously as the education and welfare of students is a primary concern. The second reason for his termination involved breaches of University policies in relation to travel and use of University resources.

The termination of his employment followed an extensive and detailed internal process, including two separate investigations undertaken by a committee chaired by a former Australian Industrial Relations Commissioner and including a union nominee."

The third time is the charm and the anti-science blog

Previously, I had reported here that I had been declared "persona non grata" on Anthony Watts' anti-science blog (WUWT). The story then developed with Anthony Watts posting a comment on the blog here to the previous posting on July 7, 2013, where he retracted the announcement previously made on his blog (here is a screenshot of the previous announcement once more),

and where he also made a pathetic attempt to present it as if the banning had been only in my head. Later, he also publicly claimed that the statement about my banning were "unsubstantiated facts on display", despite the evidence above to the contrary. But he basically said I was allowed to comment again at WUWT.

So, I went back to WUWT. It lasted only as long.

I am usually trying to reply with polite words, even when faced with the most vicious and hateful attacks or with displays of extreme ignorance, although I may not have always been successful with my tries. However, I have some problems with diplomatic approaches. I rather tend to speak my mind, sometimes up to a fault, which can escalate situations, and it has caused me some troubles and scary moments in the past, e.g., in the country where I came from.

There have been several instances, when commenters on WUWT articulated their wish that violence was applied against climate scientists, including me as a person. For instance, the late Robert E. Phelan who even was a moderator at WUWT, wrote on April 14, 2012, addressed at me, "When the peasants come for you with their pitchforks and torches, you will have brought it on yourselves."

Yesterday (July 10, 2013), some other commenter, posting under the alias Allencic, from the anti-science crowd on WUWT articulated a similar wish, (combined with the delusional notion that the AGW deniers were in a situation like Jewish scientists in Nazi-Germany. The articulation of the wish for violence against climate scientists needs a strong rationalization to justify it), even though the commenter claimed later it just had been irony.

"God help us from these fools who claim to be climate scientists. When this finally blows up and the public realizes how badly they’ve been had you might want to invest in pitchforks and torches and tar and feathers."

Anthony Watts is growing a quasi-religious anti-science cult with his blog. And he is not the only one who makes propaganda against the findings of climate science and against climate scientists, using a combination of disinformation, junk science, inciting accusations against scientists and outright lies. There are other anti-science blogs and groups who are publicly agitating (e.g., the Heartland Institute) in the same way. If Watts does not do it himself, he tolerates it when it comes from his guest authors or followers. Therefore, I consider it very possible that some AGW-denier fanatics are going to use violence against climate scientists and scientific institutions, equally motivated, for instance, as religious fanatics are attacking abortion clinics. The grounds are laid. The hate is there, the viciousness is there.

I am a peaceful person, but I am not a pacifist. I am in favor of the right to self-defense, including armed one, if someone tries to apply violence against climate scientists (or any other innocent people). I articulated this on Watts' blog, although not as elaborated and with different words. Now, I am banned again. Permanently.

Sunday, June 23, 2013

Is there evidence for a statistically significant trend change in the global surface temperature data?

Update: When one starts the trend analysis in 1999, using the the same tools as below, it takes the year 1998 with the strong El Nino out of the picture. Both the year 1999 and 2000 were years with La Nina present. One still gets some weak/medium statistical significance for the difference between the trends from 1975 to present and from 1999 to present.

Just to clarify. This has nothing to do with the denier talking point about a "global warming stop" or similar. Global warming has not stopped as one can see from the continuing increase in the ocean heat content also in recent years (the acceleration in the melting of the Arctic sea ice is another indicator):


It has more to do with how the additional energy available from the radiative perturbation from increasing greenhouse gases in the atmosphere is redistributed in the Earth system. There may be years, when the fraction of this energy that heats the deeper layers of the oceans increases at the expense of the fraction that heats the atmosphere. This may have been the case in the recent decade, and it could last a few more years. Some recent research supports this possibility (see Meehl et al., Journal of Climate (2013), doi: 10.1175/JCLI-D-12-00548.1).


Update: I have asked the question below also at Tamino's blog "Open Mind". He gave an interesting answer, pointing me to another post by him, according to which cherry-picking of a start year, which I exactly did by choosing 1998, actually changes the results from the statistical significance test and requires much higher t-values to be exceeded to make the result statistically significant. Keep this in mind, when doing such a thing. I learn something new every day.

Has anyone else noticed that the trend estimates in the data sets for the globally averaged surface temperature anomaly since 1998 have become statistically significantly different from the multi-decadal trend estimates since the mid 1970s? Not yet at the 95% level, but almost, except for the BEST land only data. This is different to the beginning of year 2012. Both the trend estimates and the 2 sigmas since 1998 have come down since then.

I use the Skeptical Science tool (, which is based on the methodology according to the Foster and Rahmstorf, IOPS (2011) paper ( For autocorrelation I use 1975 to present (What is the correct choice of the autocorrelation period?)

These are the trends and 2 sigmas in K/decade for the two time periods. The statistical Null-hypothesis is that there has been no change of the trends since 1975.

                    1975-present            1998-present         Significance level
GISTEMP:    0.169+/-0.039           0.057+/-0.14          >85%
NOAA:          0.159+/-0.036           0.033+/-0.131        >90%
HadCRUT4:  0.169+/-0.041          0.038+/-0.149        >90%

For land only data:
BEST:           0.264+/-0.063          0.144+/-0.26            < 1 sigma
NOAA:          0.275+/-0.052          0.101+/-0.205         >90%

This may be all just a statistical artifact due to the cherry picked start year of 1998 and the very strong El Nino in that year, the prevalence of La Ninas in recent years, and the deeper and prolonged solar minimum of cycle 23. The statistical significance may go away again with the adding of the data from coming years. Even a 95% significance level still allows for one false rejection of the Null-hypothesis out of 20. However, with these numbers I do not feel comfortable to reject that some empirical, statistical evidence for a significant trend change toward a lower warming trend in recent years has emerged. Those numbers actually indicate a quite high probability for such a change.

It is not inconsistent with the somewhat smaller increase in the ocean heat content (OHC) in the upper 700 m over the last decade compared to the decades before.

It may be worth to check whether the smaller slope of the 700 m OHC in recent years is statistically significantly different from the slope in the decades before.

Any opinions on those numbers and what conclusions can be drawn from it?

Saturday, June 15, 2013

Declared persona non grata at

Update, 07/07/2013: See Anthony Watts' comment below and my reply.

I just have tested the new approach, announced in April by Anthony Watts who is host of the blog, to the treatment of comments at, to see whether anything has changed for me. I commented on an article with the title "No significant warming for 17 years 4 months" by the notorious Christopher Monckton. Well, I tried. This is the result:

Thus, the only change for me is that me being banned is official now. They want to be more among themselves, without being too much interrupted by someone informed rebutting their pseudo-science. It is like with a cult. This is Anthony Watts' big change. I am certainly not the first one who actually works in the field of climate science and who got declared persona non grata over there. I feel honored.

Here is what I had submitted in reply to Monckton's article:

----- snip -----
Anthony Watts seems to think this article posted under the title "No significant warming for 17 years 4 months", written by Christopher Monckton has an important message to deliver to have it put as sticky first post on his blog for a number of days. But with closer examination, it is only the x-th repetition and variation of the "skeptic" talking point about the "global warming stop/pause" or "no warming", observed allegedly for x-number of years (the x varies according to convenience).

Mr. Monckton asserts in his article right away in the first paragraph, that "there has been no global warming statistically distinguishable from zero for getting on for two decades."

Now we are already up from 17 years and 4 months to alleged "two decades", which would make it 20 years, for which there hadn't been any warming that was statistically distinguishable from Zero, according to Mr. Monckton. Why not boldly claim "two decades", if he is at it, right?

On what does Mr. Monckton base his assertion about the alleged lack of warming for > 17 years? He bases this assertion on the fact that the temperature trend in the HadCRUT4 data set does not exceed the 95% statistical significance threshold. As correct this fact is, technically, it's also the point where Mr. Monckton misleads the audience. He equalizes a temperature trend, which does not pass the 95% significance threshold when a statistical test is done with "no warming" at all. And this is just jumping to conclusions.

Let's examine the trend since the start of 1996. There is a tool at the Skeptical Science blog, with which this can be done for the major temperature data sets:

HadCRUT4 shows a trend with a 2*sigma (=2*standard deviation, which is equal to about 95% statistical significance threshold) of 0.089+/-0.118 Kelvin/decade. Does this mean this warming is not distinguishable from Zero, generally, because the trend was smaller than 2 sigma? No, it does not necessarily mean that, because it is still possible that the trend exceeds a lower significance threshold.

So, let's check that. The trend of 0.089 in the HadCRUT4 data since the start of 1996 equals to about 1.51*sigma. The 80% threshold of statistical significance is about 1.28*sigma. Thus, even though the 95% threshold has not been exceeded (yet) since the start of 1996, one can distinguish the temperature trend in HadCRUT4 from Zero with more than 80% statistical significance. The probability to err is less than 20%. The other data sets, except for RSS that deviates to the cold side, show similar or higher warming trends since 1996, compared to HadCRUT4 (e.g., Spencer and Christy's UAH data: 0.12+/-0.2 Kelvin/decade). The satellite retrieved data have larger 2 sigma intervals, though. There is a larger interannual variability in the troposphere temperature data compared to the surface temperature data.

BTW: Even if the temperature trend was not statistically significant even at 1 sigma, this would not allow the conclusion that there was "a global warming stop/pause", since non-detectability of a trend in a time series, which is composed of trend and fluctuations is not sufficient to conclude absence of the trend in the time series. This is particularly true in this case, since there is a multi-decadal warming trend going back to the mid 70s, which is statistically significant with more than eight sigma in the surface temperature records.

Another point would be that the atmosphere is one thing, and not the major component regarding global warming. The oceans have continued to warm in the time period during which global warming allegedly has "stopped/paused". About 90% of the additional energy from the radiative perturbation due to increasing greenhouse gases in the atmosphere goes in the ocean. The ocean releases a part of this accumulated energy into the atmosphere over time. This energy release is not a linear process. A large part of this energy is released during El Ninos. And the ice caps at both poles of the planet (that includes the glaciers) have continued to melt. No one should have missed the melting trend of the Arctic sea ice, which has even accelerated over the last decade. These are strong indicators that global warming has continued also in recent years, contrary to what "skeptics" want to make believe.

In summary, Mr. Monckton's assertion of "no warming" for > 17 or even 20 years is false. It does not have any scientific validity, because it is not based on empirical, statistical evidence. And it ignores other indicators for global warming than the tropospheric/surface temperature trends.

Another assertion by Mr. Monckton is about something he calls "Dr. Santer's 17-year test", according to which "models may have failed", because the temperature trend hadn't exceeded the 95% threshold. Now, one could expect that Mr. Monckton provides some proof of source for this assertion about such a test, allegedly stated by Ben Santer. However, the link he provides leads only to another article in this opinion blog here, which was obviously not written by Ben Santer. So, is it the link to the one press release in the other article?

The press release states something that refers to 17 years. It states:

"In fingerprinting, we analyze longer, multi-decadal temperature records, and we beat down the large year-to-year temperature variability caused by purely natural phenomena (like El NiÃ'±os and La NiÃ'±as). This makes it easier to identify a slowly-emerging signal arising from gradual, human-caused changes in atmospheric levels of greenhouse gases," Santer said.

The LLNL-led research shows that climate models can and do simulate short, 10- to 12-year "hiatus periods" with minimal warming, even when the models are run with historical increases in greenhouse gases and sulfate aerosol particles. They find that tropospheric temperature records must be at least 17 years long to discriminate between internal climate noise and the signal of human-caused changes in the chemical composition of the atmosphere.

The talk in the press release is about the fingerprinting method applied by Santer. Regarding this method, it is said that one needs at least 17 years of observed tropospheric temperature data to detect the human-caused warming signal. However, there is no statement whatsoever in the press release according to which a lack of 95% statistical significance for more than 17 years meant that the model had "failed".

I actually have read Santer et al.'s paper (doi:10.1029/2011JD016263), I suspect, unlike Mr. Monckton. There is nothing in the original paper either that says anything about such a test for model predictions of the kind as asserted by Mr. Monckton. Apparently, Mr. Monckton has just made something up here, regarding the alleged "Dr. Santer's 17-year test" for model predictions using the 95% threshold of significance in the observed data.

Also, I seem to have a different understanding of the English language compared to many "skeptics", because, in my world, "at least" marks a lower boundary, whereas many "skeptics" seem to think that "at least" has equal meaning to "at most".

As for Mr. Monckton's assertion about the alleged IPCC predictions regarding the temperature increase since 2005. Mr. Monckton writes:

It is better to focus on the ever-widening discrepancy between predicted and observed warming rates. The IPCC’s forthcoming Fifth Assessment Report backcasts the interval of 34 models’ global warming projections to 2005, since when the world should have been warming at a rate equivalent to 2.33 Cº/century. Instead, it has been cooling at a rate equivalent to a statistically-insignificant 0.87 Cº/century:

Mr. Monckton asserts here that the IPCC had predicted the temperature would nearly linearly increase by 0.0233 Kelvin/year since 2005, and because the temperature in the real world had behaved differently, the model predictions were wrong. I can't call this claim by Mr. Monckton anything else than absurd nonsense. Mr. Monckton just takes the model ensemble average calculated from many individual model simulations and interprets this as a prediction of how the temperature will behave in the real world. Of course, the ensemble mean does not show the same variability as the temperature in Nature, because it's a mean! Nature only provides one single realization of all possible realizations for the same boundary conditions in a chaotic system. Each individual model simulation is like a single possible realization. It is nowhere predicted by anyone that the one single realization from Nature would follow the model ensemble mean from year to year, or even from decade to decade. A proper comparison, for instance, would be to take the full range of all model simulations, among which, BTW, there are some that actually show a "cooling" over the same time period as well, obtain the 95% range spanned by the model simulations, and then see whether the observed temperature record lies within this range, or marches outside of the range. Mr. Monckton has not done that. According to the real Figure 11.33a in the leaked draft of the AR5 report, the observed global mean surface temperature still lies within the range of the model simulations, although near the lower end.
----- snip -----

Thursday, May 23, 2013

Censored at Donner + Doria (partly in German)

Following reply to user Lollobrigida's comment got censored at the German "climate skeptic" blog "Donner + Doria", hosted by Die Welt journalist Ulrich Kulke, in the thread "Einheits-Klimaforschung - Teil 2: Das UBA Papier". It is not the only one of my comments that got censored over there. Even the ones that got finally posted needed more than one try. Here, we have another example for how informed comments that debunk fake skeptic claims are not liked at blogs of fake skeptics. The censorship happened after Mr. Kulke had written a long lamentation about how only a "unified" opinion was allegedly allowed in climate science, how critical opinions were allegedly suppressed, and he requested an "open discussion" instead. How ironic.

----- snip -----
In der Tat hatte ich die Namen von Herrn Kulke und Herrn Vahrenholt falsch geschrieben. Aber zumindest hatte ich das konsistent in dem ganzen Kommentar gemacht. Zu meiner Entschuldigung moechte ich vorbringen, dass ich mich mehr auf den Inhalt konzentriert hatte, so dass mir das nicht aufgefallen war. Es war keine Boeswilligkeit. Ich werde versuchen, die Namen in der Zukunft korrekt zu schreiben.

Sie behaupten:

"Es bleibt dabei: Das Ausmaß, inwieweit der Mensch an der Klimaerwärmung beteiligt ist, ist eben nicht unumstritten, da klaffen die einzelnen Studien weit auseinander."

Ihre Behauptung ist nun auch nicht sehr konkret. Wie weit ist denn "weit auseinander"? Wieviele Studien gibt es denn, die infragestellen, dass die globale Erwaermung real sei und die hauptsaechliche Ursache der statistisch signifikanten globalen Erwaermung der letzten Jahrzehnte menschliche Aktivitaeten, insbesondere Treibhausgasemissionen waeren? Gibt es mehr als den sehr kleinen Anteil an Studien, der auch von Cook et al., (2013) festgestellt wurde? Wenn Sie das behaupten, auf welche Belege stuetzt sich Ihre Behauptung?

"Selbst der Entwurf für den nächsten Assessment Report des IPCC, der im September herauskommt, geht inzwischen von nicht mehr als 50 Prozent als gesichert heraus, und das will schon viel heißen."

Abgesehen von der Ethik-Verletzung, die der/diejenige begangen hat, der/die den Entwurf oeffentlich verbreitet hat, wuerde ich doch gerne mal die Quelle wissen, wo Sie diese Behauptung herhaben. Ich vermute, von irgendeinem "Skeptiker"-Blog. Denn da sind Sie einer Luege aufgesessen, und Sie haben es anscheinend nicht fuer noetig gehalten, die Aussage zu ueberpruefen. Der draft report sagt naemlich etwas anderes. Der sagt aus, dass es extrem wahrscheinlich sei, dass mindestens 50% der globalen Erwaermung seit Mitte des letzten Jahrhunderts durch menschliche Aktivitaeten verursacht worden sei, und dass der Beitrag der Treibhausgase zum Trend von ca. 0.6 K von 1951 bis 2010 sehr wahrscheinlich zwischen 0.6 K und 1.4 K betraegt (Seite 10-3).

"Dabei sind darin noch nicht einmal die letzten Studien berücksichtlgt, die feststellten, dass die CO2-Sensitivität offenbar deutlich zu hoch bewertet wurden".

Relevant waeren fuer die Frage des Konsenses unter den Wissenschaftlern, ob AGW real ist, wenn es neue relevanten Studien zur Klimasensitivitaet gabe, die genau aus diesem Konsens herausfallen. Ansonsten gab es schon immer einige Studien mit niedrigeren Schaetzungen zur Klimasensitiviaet und andere mit hoeheren Schaetzungen. Es ist ja nicht so, dass da bisher nur ein einzelner fixer Wert als gueltig angesehen worden waere. Auch die neueren Schaetzungen werfen vorherige Aussagen, z.b im IPCC Report 2007 nicht ueber den Haufen, selbst wenn der Wert, dem die hoechste Wahrscheinlichkeit zugeschrieben wird, etwas niedriger ausfaellt.

"mal abgesehen von den Studien, die zwar eine menschliche Beteiligung konstatieren, aber den Ruß/Albedoeffekt deutlich in den Vordergrund rücken."

Worueber reden Sie? Es gibt keine Studien, die zu dem Ergebnis kommen, dass der Soot-Albedo Effekt auf das Klima groesser sei, als der Effekt der anthropogenen Treibhausgasemissionen, nicht mal gleich so gross. Es sei denn, ich habe da was uebersehen. Dann muessten Sie mir die Studie nennen, die zu so einem Ergebnis gekommen sein soll. Die Angabe des doi-keys genuegt.

"Hier eine Einheitlichkeit vorzugaukeln, wirkt reichlich hilflos."

Wer behauptet denn diese "Einheitlichkeit" bzgl. jeden Aspektes zur globalen Klimaaenderung? Oder ist diese Behauptung ueber die angebliche Behauptung einer "Einheitlichkeit" vielleicht nur ein Strohmannargument? Diejenigen, die das Wort "Einheitlichkeit" gebrauchen, sind doch auch nur Herr Kulke und Sie und vielleicht Ihnen gleichgesinnte Personen.

Dass bestimmte zentrale Aussagen in einem wissenschaftlichen Fachgebiet mit der Zeit den Status eines Paradigmas bekommen, ist nicht das gleiche wie "Einheitlichkeit" zu allen Fragen.

"Wo fangen eigentlich die "Skeptiker" an, und wo ist man noch im erlaubten Bereich? Und ab wann ist man "falscher Skeptiker", kein richtiger mehr?"

Das ist gar nicht so schwer auseinanderzuhalten, wer ein wahrer und wer ein falscher Skeptiker ist. Das haengt nicht davon ab, welcher wissenschaftlichen Hypothese oder Theorie man skeptisch gegenuebersteht, sondern davon, welche Form von Argumenten bzw. Pseudoargumente man gegen die Hypothese oder Theorie vorbringt. Man erkennt die falschen Skeptiker an der Methode. Wahre Skeptiker verwenden wissenschaftliche Argumente, und wenn sie eine Hypothese oder Theorie ablehnen, dann stellen sie eine alternative Hypothese auf, und testen diese mit der gleichen wissenschafltichen Rigorositaet, die sie von anderen Wissenschaftlern erwarten. Skeptizismus gehoert zum beruflichen Profil eines Wissenschaftlers.

Falsche Skeptiker greifen die wissenschaftlichen Hypothesen und Theorien, die von ihnen abgelehnt werden, mit unwissenschaftlichen Argumenten an, z.b, indem sie stattdessen persoenliche Angriffe auf die Wissenschaftler fahren, die diese Hypothesen oder Theorien in ihren Publikationen veroeffentlichen, oder sie bedienen sich logisch trugschluessiger Argumente, cherry picking, oder sie verbreiten schlichtweg tatsachenwidrige Behauptungen. Oft kommt das auch mit Verschwoerungsfantasien auf Seiten der falschen Skeptiker daher. Und aufgrund der stark politischen und ideologischen Motivierung, die viele der falschen "Skeptiker" antreibt, sieht man auch haeufig, dass politische und ideologische Argumente gegen die wissenschaftlichen Hypothesen und Theorien vorgebracht werden.

Sie, z.B., bedienen sich einer fuer falsche Skeptiker typischen Argumentationsfuehrung, in Ihrer Entgegnung auf meine Aussagen zu der angeblichen "Pause in der Klimaerwaermung". Waehrend ich inhaltliche Argumente dazu gebracht habe, wie mein Verweis auf die logisch und methodisch falsche Schlussfolgerung, die aus fehlender statistischer Signifikanz der Temperaturaenderung in der Troposphere ueber die letzten 15 Jahre gezogen wird, und mein Verweis auf andere Indikatoren dafuer, dass sich die globale Erwaermung fortsetzt, bedienen Sie sich des logisch trugschluessigen Arguments des Appells an die (angebliche) Mehrheitsmeinung, um meine Argumente vom Tisch zu wischen. Und mit extremer Wahrscheinlichkeit koennen Sie Ihre Behauptung, dass meine Argumente eine Aussenseiteransicht unter den Klimawissenschaftlern waere, auch gar nicht mal belegen.
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Friday, April 12, 2013

What got me snipped from - 11

Werner Brozek wrote a new article at about his research on noise in the global temperature record. The reply below to the article, which I submitted to the thread as a comment has not been published there. This is the second one of the couple of comments censored at Anthony Watts' blog, which I announced before to document here. Since I apparently have been blacklisted at Watt's blog by default, currently, I am not going to put any more efforts into trying to comment over there, unless I am not treated differently any more compared to how the ones are treated who agree with Anthony Watts and his friends.

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Werner Brozek wrote:

For example, do we mean that the slope of the temperature-time graph must be 0 or do we mean that there has to be a lack of “significant” warming over a given period? With regards to what a suitable time period is, NOAA says the following:

    ”The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”

To verify this for yourself, see page 23 here.

And once again the quote from the NOAA report is misrepresented by you. The quote still refers to the ENSO-adjusted temperature record as it has done in the past. However, you omit this information and use it here as if the quote had established some criterion for the unadjusted temperature record. You do so, although you have been pointed out already in the past that the quote applies to ENSO-adjusted data.

Your article does not hold what the headline promises. There is no analysis in there whatsoever that allows any conclusion with respect to whether climate models are "realistic". In order to do such an analysis one would have to do an actual comparison between model capabilities to simulate specific features of the climate system and real world data. Which you haven't done.

You only show some "flat lines" in the temperature record going back different numbers of years, depending on which specific record is chosen, which by itself does not allow any conclusion with respect to the presence or absence of a trend or regarding climate models, since one always will find periods with "flat lines" in any arbitrary time series that is composed of trend and fluctuations, if one chooses the time interval only short enough. One finds similar behaviour in individual simulations with climate models. You confine your examination on those time intervals, where the noise is still masking the long-term trend. This looks to me like a pointless undertaking, unless you want to study the features of the noise.

Models aside, your exercise doesn't even provide evidence for claims like "global warming stopped", or similar. Not being able to detect a trend, because the data set is too small does not allow the conclusion that the trend was not there. None of the seemingly "flat" temperature records, which you show here, can be statistically significantly distinguished from the multi-decadal surface or lower tropospheric warming trend, which itself is statistically significant with 3 sigma or more.

You state:

For this analysis, data was retrieved from This analysis indicates for how long there has not been significant warming according to their criteria. ... (To the best of my knowledge, SkS uses the same criteria that Phil Jones uses to determine significance.)

This looks to me like another misrepresentation of what others said. Or show me where Phil Jones or anyone at Skeptical Science supposedly claimed that "warming" was significant at 95% or 2 sigma, or there was no significant warming at all. Please provide a source where anyone said something like that, allegedly.

If warming is significant with, for instant higher than 90% probability, but lower than 95% probability, it is still statistically significant. Only the probability to have wrongly rejected the Null-hypothesis (which would be no significance warming in this case) is higher. To claim that there was no "significant warming" in such a case is just wishful thinking.

As for your conclusion:

After looking at the above facts, do you feel that we should spend billions to prevent catastrophic warming? Or do you feel we should take a “wait and see” attitude for a few years to be sure that future warming will be as catastrophic as some claim it will be?

You could have started with that in your posting. Then it would have been clear from the beginning, that your starting point is political and ideological preconception that you apply as a filter for your perception and examinations. That plausibly explains the motivation for your efforts here and for your misrepresentations.

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Wednesday, April 10, 2013

What got me snipped from - 10

The purpose of the post is merely to document the censored reply I gave to one of the participants in the thread. It was the repeated, and yet futile try to explain what institution employs me and which one does not. One could be astonished about the notorious refusal of many of the fake skeptics to let in anything that is in contradiction to their preconceived views, if it was not just another example of the usual modus operandi of this crowd, which can be observed at many occasions. I frankly admit that I may not be fully informed about all the nuances employment contracts can have, but I am pretty sure that if there is no contract that states an employment relationship between two parties, then there is no employment relationship in legal terms. The following is not particularly exiting. It is just for the record, since I was prevented to reply at the location where the claims were made.

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J. T. Jones wrote on April 8, 2013 at 7:16 pm in

If they were a contractor doing the work the government contracted them to do, it would be entirely legal and relevant to refer to them as being employed by the government as they (or the company that hired them) would indeed have a government employment contract. on the other hand, It wouldn’t be legal or relevant to refer to them as a federal employee, as they are not directly employed by the government.

You haven't answered my question whether you have an employment contract with the federal agency, and whether you could make legal claims against this federal agency regarding your employment. If you work for a company that has a contract with the federal agency to provide specific services to the federal agency, your employment contract is not with the federal agency. It's with the contracting company instead. You are employed with the contracting company. Or please explain to me based on what legal document you are claiming you were employed with the federal agency.

The simple facts of the matter is NASA is footing the bill for work that you do on their behalf. That is what is called employment.

No, employment is a legal contract between two parties. But it doesn't even work in the way you think regarding the relationship between Columbia University and NASA. It's not like the relationship between contractors who provide services for NASA (e.g., IT services) and NASA, and the contractors then employ people who do this work. Instead, it's a collaboration between Columbia and NASA to the benefit of both parties in the collaboration. The Columbia scientists working at GISS aren't even necessarily paid with money coming from NASA. They are paid from federal grant money like most researchers at Columbia, coming from various federal agencies, based on proposals that are submitted by the researchers and Columbia to the federal agencies, like NSF, DOE, NOAA, and also NASA, but not necessarily NASA. There is nothing in my contract that says I was employed to provide services to NASA. My legal status and my contract as a Columbia employee is not different to any contract of any other Columbia researcher who works in any other lab on the Columbia campus.

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Tuesday, April 9, 2013

Update Regarding My Posting Status at

As reported before, I had been banned from posting comments at the AGW-"skeptic" blog Yesterday, I was able to publish some comments again. However, this was only until last night. Since then, none of my comments I submitted there have appeared. I take from this that I am stilled banned from posting at the blog by default. Publishing some comments submitted by me yesterday seems to have been at a whim of Anthony Watts, which apparently did not last long. This prevents me from sending rebuttals to claims made over there by some of the fake skeptics, including the ones about my person, which have reached a new level of absurdity. I am not going to try again and again to find out when I am allowed to post something and when I am not. If Anthony Watts does not want me to write at his blog so be it.

I am going to publish a couple of the censored comments at this place here later.

Wednesday, February 27, 2013

What got me snipped from - 9

Today, I got (temporarily, I was told. I will see) banished from posting comments on the anthropogenic global warming (AGW) denier blog Anthony Watts, weather man and blog host, seems to have got upset (while seemingly projecting his own emotional reaction on me, which made him want to punish me). I apparently have been too critical toward him and his blog. I diagnosed hypocrisy after Watts had made accusations (in a reply at the end of the linked comment) against the hosts of the Skeptical Science blog. They allegedly were "fast and loose with spinning the truth to suit their agenda". The irony is that Watts writes such things below a post on his own blog written by the newspaper journalist and spin-doctor (well, he is not really a doctor of any profession) Christopher Monckton who is known for his notorious AGW denying propaganda and spread of disinformation with respect to empirical climate data and results from research in climate science. And this is only one post in Watts's blog. Disinformation, spin, and propaganda can be found in almost every single article that is posted on the blog.

I challenged Monckton's elaboration here and here with respect to their accuracy and scientific validity. The first comment by me got a reply by Monckton, in which he only repeated previous assertions without anything to back them up, plus some ad hominem arguments against my person. So far, I have not seen anything by Monckton after my second rebuttal to him.

In his announcement to punish me with banning, Watts declared I should not write there anymore, as someone who was funded with money coming from taxpayers. True it is, my whole life is publicly funded, all the expenses that are needed to sustain my lifelihood, everything I do is basically taxpayer funded, since I do not have any significant private income sources, only my salary funded with government grants. Of course, Watts is free to make whatever rules he likes for who is allowed to write on his blog, and no one's rights are violated by this. However, I wonder whether he thinks this should be the case in society generally that people whose incomes come from public funds should not have the same constitutional rights as the ones with income from private sources. And what other rights and entitlements should be limited for publicly funded people compared to privately funded ones, according to Watts.

I am going to see whether my banishment is going to be temporarily. I do not plan to back off from criticizing Watts's and friends's crooked approach toward science and truth on his own blog, from the perspective of someone who works in the field of climate science. If he does not want to have it there he will have to banish me permanently.

Here are the comments that got censored by Watts from the mentioned thread. The first one disputes the meaning of a quote from the NOAA State of the Climate Report 2008 (Attention, this file is 14.9 MB), how it had been presented in a previous comment by another user. The second one just states some facts about the trend of the near surface and lower tropospheric temperature trend over the time period of the last 17 years.

-----  snip -----

Werner Brozek, on February 26, 2013 at 8:42 am, in


"My purposes are at least two fold. I think it is fairer to say a slope is 0 than to say a slope could be 0 at a certain level of significance, but that it could also be much higher at the higher end."

I don't really understand what "fair" or "fairer" is supposed to mean in the context of assessing data as empirical evidence to support or contradict a scientific statement. What is required in science is to be precise. A statement about a slope of a trend, when it is supposed to be empirical evidence for something, is quite meaningless without any information about the error band of the slope. You can do a trend analysis, and when the result shows a Zero-trend, it is always only a statistical estimate. It does not mean that you really have the information that the trend was exactly Zero. You only have the information that it was Zero within a range of uncertainty for a specified probability. There is no other way here than to make a probability statement. If the statistical significant trend of the temperature increase since the 1970ies lies within the error band of the temperature record of the recent years, then the conclusion that both trends probably did not belong to the same statistical population cannot be validly drawn from such a statistical trend estimate.

If uncertainty ranges did not matter, I could equally claim that the warming trend was something between 1.2 and 4.7 K per decade now, because that's what the trend analysis currently gives as result for all the major data sets from the beginning of the year 2012.

"PDF document For anyone else who wants it, the exact quote from pg 23 is:
”The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”

So I admit that Hadcrut4 does NOT meet this criteria yet, but three other data sets do. See the bolded ones below."

You say everyone who wants can check the quote under the link. However, I wonder whether you yourself have bothered to check whether the quote really says what you assert here it says, because what you bring here is a misrepresentation of its meaning. I already have discussed this quote previously, like here:

This is the longer version of the quote:

"We can place this apparent lack of warming in the context of natural climate fluctuations other than ENSO using twenty-first century simulations with the HadCM3 climate model (Gordon et al. 2000), which is typical of those used in the recent IPCC report (AR4; Solomon et al. 2007). Ensembles with different modifications to the physical parameters of the model (within known uncertainties) (Collins et al. 2006) are performed for several of the IPCC SRES emissions scenarios (Solomon et al. 2007). Ten of these simulations have a steady long-term rate of warming between 0.15° and 0.25ºC decade–1, close to the expected rate of 0.2ºC decade–1. ENSO-adjusted warming in the three surface temperature datasets over the last 2–25 yr continually lies within the 90% range of all similar-length ENSO-adjusted temperature changes in these simulations (Fig. 2.8b). Near-zero and even negative trends are common for intervals of a decade or less in the simulations, due to the model’s internal climate variability. The simulations rule out (at the 95% level) zero trends for intervals of 15 yr or more, suggesting that an observed absence of warming of this duration is needed to create a discrepancy with the expected present-day warming rate.”
(, p. 23, Figure 2.8b on page 22 illustrates this graphically).

From the longer version you have only quoted the last sentence. The whole two pages where the quote is from are about the question whether there is a discrepancy between model simulations and observations. The report refers to a study (Collins et al., CD, 2006, doi: 10.1007/s00382-006-0121-0), where many simulations were carried out with one climate model, HadCM3, with varied configurations. The important information you have left out is that the comparison presented in the report is done for the temperature data after adjusting them for the contributions to the temperature series that come from ENSO variability. Therefore, your presentation that the bolded temperature series fulfill this criterion that you quoted is false, since you don't have calculated out those contributions of the temperature variability that come from ENSO.

If you wanted to see whether those temperature data sets fulfill this criterion, you would have to do the ENSO-adjustment exercise first.

Actually, if one really is precise this criterion of "15 years" would only apply to the simulations with the one model, HadCM3, that was used for the mentioned study. The internal variability of different climate models is not all the same. Thus, other models might have given a somewhat different answer, if the study had been performed with those models. Perhaps, the answer for some models, the ones with smaller internal variability, would have been 12 or 14 years, or for other ones, ones with higher internal variability, 17 or maybe 20 years. We don't know the answer for those other models.

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The second censored comment:

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The claim that there had been no temperature rise for 17 year isn't even factually correct, since all the trend estimates for the major data sets show a positive trend, with GISTEMP more than 90% probability of significance, and NOAA and HadCRUT4 with more than 80% probability of significance. The trend estimate for UAH is higher than for these surface data sets, but it is not statistically significant because of the higher variability of the tropospheric temperatures, compared to near surface temperatures. RSS only shows a small positive trend.
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Wednesday, February 13, 2013

What got me snipped from - 8

And yet another thread where a comment by me got vanished at The topic to which I replied are accusations against late climate scientist Stephen Schneider to have promoted lying to the public. The accusations have been stated by fake skeptics for years, mostly based on a falsified quote from an interview Stephen Schneider gave to the magazine Discover in 1989.

In my comment I replied to comments by four other participants. This is the comment that was seemingly disliked:

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Mark Bofill wrote on February 11, 2013 at 10:27 am in


Bofill, you just have crossed the line. You don't need to further pretend that you were seriously interested in a discussion with me.

richardscourtney wrote on February 11, 2013 at 7:41 am in


Every time when Courtney is exposed to have spread falsehoods or supporting falsehoods, like when he is exposed to make false claims about the NOAA Report from 2008, or here, he is shouting "Liar!" over and over again. He behaves like the thief who is loudly shouting, "Stop the thief!" to deflect the attention from himself.

D.B. Stealey, on February 11, 2013 at 10:44 am in

requests that I apologize to Gail Combs. Ridiculous. What for? I should apologize, because she posted a falsified quote? Anthony Watts may have tried to display this here as an innocent mistake, because the falsified quote had been spread before by some newspapers (and in the fake skeptic blogosphere). Only, this explanation is not believable to me, since Gail Combs provided a link together with the quote, which pointed to a correct version of the quote. Thus, she must have known about the not falsified version. Nevertheless, she presented the falsified one.

Bruce Cobb, on February 11, 2013 at 8:10 am in

expressed his regret that Stephen Schneider wasn't around anymore to tell climate scientists what he really meant.

However, that is not a problem, since he had done that already when he was still alive.

For instance in here:

Go to page 5, Stephen Schneider writes there:

"Vested interests have repeatedly claimed I advocate exaggerating threats. Their “evidence” comes from partially quoting my Discover interview, almost always -like Simon - omitting the last line and the phrase “double ethical bind.” They also omit my solutions to the double ethical bind: (1) use metaphors that succinctly convey both urgency and uncertainty (pg. xi of Ref. 3) and (2) produce an inventory of written products from editorials to articles to books, so that those who want to know more about an author’s views on both the caveats and the risks have a hierarchy of detailed written sources to which they can turn.3,4,5 What I was telling the Discover interviewer, of course, was my disdain for a soundbite communications process that imposes the double ethical bind on all who venture into the popular media. To twist my openly stated and serious objections to the soundbite process into some kind of advocacy of exaggeration is a clear distortion. Moreover, not only do I disapprove of the “ends justify the means” philosophy of which I am accused, but, in fact have actively campaigned against it in myriad speeches and writings. Instead, I repeatedly advocate that scientists explicitly warn their audiences that “what to do” is a value choice as opposed to “what can happen” and “what are the odds,” which are scientific issues (e.g. p. 213 of Ref. 3). I also urge that scientists, when they offer probabilities, work hard to distinguish which are objective which are subjective, as well as what is the scientific basis for any probability offered. For such reasons I was honored to receive, in 1991, the AAAS/Westinghouse Award for the Public Understanding of Science."
(Stephen Schneider, Don’t Bet All Environmental Changes Will Be Beneficial, APS News, 1996, 5(8), p. 5,

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Tuesday, February 12, 2013

What got me snipped from - 7

More than a week has already passed. Thus, it is safe to assume my following comment to the smear post by Anthony Watts against William Connolley got vanished back then after submission to Watts's blog. Here is my comment:

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Anthony Watts wrote:

"Wikipedia climate fiddler William Connolley is in the news again"

"in the news again" means here, Kopp-online, one of worst garbage publishers, which is known for spreading esoteric and pseudo-scientific views, conspiracy fantasies and outright lies, in the German language online world, published some dreck about Connolley, an opinion article filled with lies, filled with assertions not backed up with anything, filled with innuendo and conspiracy fantasy. Then the author quotes and references his own Kopp-article in his own blog, which then is quoted and referenced by Anthony Watts here. And soon, it likely is going to be further spread all around the "skeptic"-blogosphere. This is how some "news" are being created.

Unbelievable but true: The Wikipedia umpire on Climate Change was a member of the UK Green Party and openly sympathized with the views of the controversial IPCC. So it was not a referee, but the 12th Man of the IPCC team.

I’m not sure how accurate the translation is, but it suggests he was somehow part of the IPCC “short list” team.

What is "the IPCC 'short list' team"? The central committee of the evil "AGW hoax" conspiracy?

No, it means something else here. It's a sports metaphor, through which it is asserted that Connolley lacked objectivity as an author or administrator of Wikipedia because of his former Green Party membership and because "he openly sympathized with the views of the controversial IPCC".

"he openly sympathized with the views of the controversial IPCC". This statement is obviously derogatorily meant, but it comes as pure innuendo. What is this even supposed to mean? What are the alleged "views of the controversial IPCC", with which he "openly sympathizes"? The scientific views on climate change of mainstream climate science, as compiled and synthesized in the IPCC report? Or what else is meant?

So, people who agree with the mainstream views in a scientific field should not write or edit articles about topics in the field in an encyclopedia? And if they do anyhow, it's just "unbelievable"! How dare they!

It's really an irony that the crowd here is ranting about Wikipedia, and at the same time is taking something at face value, which comes from a garbage source like Kopp-online, as soon as it seems to confirm the preconceived views. Anyone who values science and truth should stay far away from such a source, though.

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Thursday, January 31, 2013

What got me snipped from - 6

This time a comment of mine, which I had submitted on January, 24, 2013, in reply to the posting "Burt Rutan: 'This says it all and clear'" got vanished or never appeared at Anthony Watts's blog "Watts Up With That?". My reply listed some major flaws of the posting. It is one of the many examples how fake skeptics lie using cherry picked data and flawed statistics. I addressed this pseudo-scientific approach also in the post "How to create a false 'global warming standstill'".

Here is the comment:

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Three major flaws in the post:

1. Cherry picking of data intervals and the data set to support the desired message.

2. Drawing scientifically invalid conclusions from changes in limited data, which are not statistically significant.

3. Straw man argumentation, where something is being "refuted" that is not being stated (as if any climate scientist has claimed that CO2 was the only factor influencing the global atmospheric or surface temperature record, and that there was a linear relationship between CO2 emission or CO2 mixing ratio in the atmosphere and observed temperature record).

But the crowd here is generally applauding. So much for the skepticism of "skeptics".

I don't know for what purpose Mr. Watts posted this. But if the purpose has been to expose what I am seeing here, it is a full success.

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Friday, January 25, 2013

How to create a false "global warming standstill"

  1. One choose a data set of global tropospheric (e.g., UAH, RSS) or surface temperature estimates (e.g., NASA/GISS, NOAA/NCDC, HadCRU), preferably one that has the strongest bias to the cool side.
  2. One finds a time interval in the data set, which is sufficiently short enough so that a statistical trend estimate does not provide any statistically significant warming trend. The large variability within the data on the short time interval makes sure of this. Even better, if the statistical estimate of the trend is close to Zero or negative. In latter case, one can claim "global cooling!" Statistical significance does not matter in this case. It only matters, if it comes to denying a global warming trend.
I have done this exercise for the RSS data of the lower troposphere temperature. And voila! There has not been just one global warming "standstill". There has been even two over the last 34 years, I have discovered using the woodfortrees tool.

According to this, the first "global warming standstill" occurred from 1979 to 1993 (inclusive). The statistical estimate (using this neat trend calculator at the Skeptical Science blog, which is based on [1]) of the trend is 0.012 Kelvin/Decade. The 2-sigma (about 95%) confidence interval is +/-0.229 Kelvin/Decade. As one can see, it is quite large. Then there is the recent "global cooling" from 1997 to today with a trend of (-0.003+/-0.229) Kelvin/Decade. No statistically significant cooling, but what "skeptic" is going to care about that, as long as "cooling" can be claimed.

What about the small interval between the "global warming standstills"? The positive trend estimate in this small time interval is not statistically significantly different from a Zero-trend either: (0.164+/-1.689) Kelvin/Decade. Therefore, since none of the separate time intervals shows any statistically significant global warming, the brave "skeptic" concludes, there has not been any global warming for 34 years at all! It is all a lie, a big global warming hoax! Invented by sinister forces for their own mean purposes.

What now? Now we repeat the statistical trend estimate for the whole time interval from 1979 to today:

The statistical estimate for the trend over the whole time interval is (0.133+/-0.073) Kelvin/Decade. There is a clear global warming trend, which is statistically significantly different from a Zero-trend by more than 3-sigma, which means that the probability to have a false positive signal relative to the noise in the data within the time interval is less than three out of a thousand.

No global warming and presence of global warming cannot be both true at the same time. A statement and its negation cannot be true at the same time. One of the two approaches must be wrong. And it is not the second one.

What does this teach us?
  1. One can get easily fooled by noise, if one chooses too short time intervals of the data in time series analysis. In any time series, once always can find a time interval short enough, for which the noise becomes so large it masks any trend in the data series.
  2. A failure to find a statistically significant trend in a time series does not refute the hypothesis of the presence of such a trend, since one cannot logically exclude the possibility that the lack of statistical significance is only due to a too small sampling size of the data.
  3. Empirical, statistical evidence for a true global warming "standstill" or at least for a trend change could be provided by showing that the trend over the recent shorter time interval is statistically significantly different from the statistically significant warming trend that has been observed over the whole of the recent decades. This is not the case for the RSS data set above (and neither for any of the other mentioned ones). The 2-sigma interval for the RSS temperature data since 1997 is +/-0.229 Kelvin/Decade. The multi-decadal trend from 1979 to today lies well within its boundaries. Therefore, claims about a "global warming standstill", using too short time intervals from these data sets and flawed conclusions from statistical trend analysis, do not have any scientific validity.
[1] Foster, G. and Rahmstorf. S, 2011, Global temperature evolution 1979–2010, Environ. Res. Lett. 6(4), 044022, doi:10.1088/1748-9326/6/4/044022