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Monday, August 27, 2012

Is Soon To Be Hurricane Isaac Making Landfall At New Orleans?

Hurricane warnings have been issued for the gulf coast. According to the National Hurricane Center, current tropical storm Isaac is predicted to not become a major hurricane, unlike Hurricane Katrina, which hit New Orleans in 2005 with catastrophic consequences for the city. Nevertheless, anyone in a path of a hurricane should be properly prepared (see here).

Sunday, August 26, 2012

Fake Skeptics Versus True Skeptics

Since I have previously used the term Fake Skeptics, perhaps some explanation is required what is meant with this term. I am distinguishing between fake skeptics and true skeptics regarding scientific debates, based on the form of the arguments and the motivation behind the arguments. The phenomenon of a, if not necessarily large, but the more noisy group of people who act as fake skeptics is for instance particularly present regarding the findings in the field of climate science, since those findings have become highly politicized due to their implications for the human civilization and economics and politics all over the planet.

Fake Skeptics do not argue on the grounds of science, they mostly use non-scientific arguments to attack the findings of science. They misrepresent the science, use logical fallacies, acknowledge and interpret empirical data only very selectively, e.g., by cherry picking those, insofar those appear to be in support of their views. The thinking is governed by cognitive biases too a large degree. The driving force is not primarily scientific curiosity, and the motivation for arguing against findings of science is mostly not just some scientific disagreement. Findings from scientific research are rejected, because those findings are in contradiction to preconceived economical, political, ideological, or religious views. Consequently, since the scientific arguments are lacking, fake skeptics often resort to attacks not just against the results from research, but also against the scientists who have presented those results. Scientists who are presenting results from research which are not liked are being defamed and smeared. Accusations, insinuation, or the use of innuendo against those scientists, asserting or suggesting fraud and malicious manipulation of data and results from scientific studies are common. Resort to conspiracy theories fantasies is common too, which is explainable. How else can the worldview be made whole, if most scientists who work and publish in the field say something else? The ones who act as fake skeptics are mostly people who are not directly involved in the area of research the findings of which are being rejected. Since scientific arguments and rigorousness are lacking, fake skeptic arguments are usually not presented in scientific publications in specialist journals of the field due to the filter mechanism of the peer review process. Instead, they are mostly found in other venues, nowadays especially in Internet opinion blogs, since it is not mandatory in those to uphold strong scientific standards.

True Skeptics are, in contrast, driven by scientific curiosity and they wish to acquire knowledge about the cause-effect relationships that govern the workings of the object or system that is being studied and debated. They argue based on science. If they do not agree with findings presented by scientists, they do this using scientific arguments. They embrace the scientific method and test alternative explanations, if they hypothesize those, against empirical data. True skeptics present their alternative hypotheses and theories, once they have been worked out sufficiently, in the peer reviewed specialist journals of the field, i.e., they uphold for themselves high scientific standards. Personal attacks against scientists who are presenting alternative, competing hypotheses and theories are not being considered as legit arguments against those hypotheses and theories. Professional scientists need to be true skeptics in their daily work. It is part of their professional profile.

Thursday, August 23, 2012

Has global warming stopped? - An examination of a fake skeptic's argument

I'm documenting here my reply I gave somewhere else to a couple of talking points that are frequently used in the fake skeptic universe. One talking point is that global warming had allegedly stopped, based on the fact that statistical significance of the temperature trend on some short time scales like 10 years has been missing. The second one is the assertion that the observed temperature trend was in contradiction to the carbon dioxide change over time. Both are common straw man arguments applied to create doubt toward the results from research in climate science that there was a global warming trend which can be distinguished from noise due to natural variability, and that an increase in the mass of carbon dioxide gas in the atmosphere causes global warming.

Fake skeptic statements are in italic.

----- snip -----
A clear example of this falsehood has been debated in this thread. It is a fact that there has been no statistically discernible rise in global temperature over the last 10 years. However, there was statistically discernible rise in global temperature over each of the three previous 10-year periods. Clearly, the statistically discernible rise in global temperature in each decade from 1970 to 2000 has stopped while, importantly, the rise in atmospheric CO2 has not stopped.

So, we have had arguments on this thread concerning whether a 10-year period is – or is not – meaningful. Clearly, in this case it is meaningful: i.e. it means the observable global warming since 1970 has stopped. This is an incontrovertible conclusion.

Let me repeat with my own words. The speaker asserts that each 10-year period from 1970 to 2000 showed a statistically significant warming. He also asserts, the absence of a statistically significant warming in the decade after 2000 implies the conclusion there hadn't been any global warming after the year 2000, in contrast to the previous 10-year periods. This conclusion was incontrovertible.

Now let's check the facts and then let's examine the conclusion.

First the trends for each 10-period with their 2-sigma significance threshold. I use the trend calculator at the Skeptical Science Blog:

I split the 10-year periods as follows: 1971-1980, 1981-1990, 1991-2000, 2001-2010

Trends in K/decade.


GISTEMP:   0.144+/-0.330
NOAA:      0.152+/-0.333
HADCRUT3v: 0.134+/-0.389
HADCRUT4:  0.16+/-0.359

None of the trends in the four data sets is statistically significant at 95% probability or above over the 10-year period 1971-1980.


GISTEMP:   0.091+/-0.345
NOAA:      0.100+/-0.290
HADCRUT3v: 0.084+/-0.301
HADCRUT4:  0.082+/-0.291
RSS:       0.046+/-0.502
UAH:       0.058+/-0.531

None of the trends in the six data sets is statistically significant at 95% probability or above over the 10-year period 1981-1990.


GISTEMP:   0.298+/-0.381
NOAA:      0.314+/-0.338
HADCRUT3v: 0.356+/-0.382
HADCRUT4:   0.301+/-0.356
RSS:        0.447+/-0.594
UAH:        0.367+/-0.640

None of the trends in the six data sets is statistically significant at 95% probability or above over the 10-year period 1991-2000.


GISTEMP:   0.019+/-0.277
NOAA:      -0.021+/-0.244
HADCRUT3v: -0.069+/-0.234
HADCRUT4:   -0.012+/-0.249
RSS:        -0.161+/-0.376
UAH:         -0.065+/-0.410

None of the trends in the six data sets is statistically significant at 95% probability or above over the 10-year period 2001-2010.

So, in none of the consecutive decades 1971-1980, 1981-1990, 1991-2000, 2001-2010 had there been a statistically significant warming trend with a probability of 95% or above. According to the "logic" of the speaker, the absence of a statistically discernible warming trend implies that global warming "has stopped". Thus, no global warming at all for four decades.

Now let's do the trend analysis for all 4 decades together:


GISTEMP:   0.169+/-0.038
NOAA:      0.168+/-0.035
HADCRUT3v: 0.165+/-0.038
HADCRUT4:  0.177+/-0.036

Now we get a statistically significant trend with a probability of at least 95% for all four data sets from 1971 to 2010, although, according to the "logic" of the speaker, the absence of global warming in each of the four decades was "incontrovertible" due to the absence of a statistically discernible trend in each of the four decades.

Global warming present and global warming absent. Both can't be true at the same time. It appears to be a conundrum. But it is none. the speaker has just applied the same logically fallacious argument again, which had been applied by him before. The logical fallacy is to draw the conclusion that a trend was absent in a data set from the fact that a trend was not detectable in the data set on a given time scale. This conclusion is logically fallacious, since the non-detectability of a trend in a data set does not logically exclude the possibility that the trend is only masked by noise on the time range of the analysis and only detectable when the time range is increased.

The speaker's asserted conclusion, it was incontrovertible that global warming "has stopped" after the year 2000 is scientifically not valid, since it is based on a methodologically flawed analysis.

And that conclusion is important. More than 80% of anthropogenic GHG emissions were after 1940. There was no discernible rise in global temperature from 1940 until ~1970. And the rise from 1910 to 1940 is the same as the rise from 1970 to 2000 when it stopped. This indicates that there is no discernible effect of the anthropogenic GHG emissions on global temperature.

The speaker's repeated assertion the global temperature increase before 1940 despite the fact that most of the CO2 emission has occurred after 1940, and the absence of a discernible temperature increase between 1940 to 1970 despite increasing CO2 concentration in the atmosphere were in contradiction to the explanation that increasing CO2 concentration in the atmosphere causes global warming is also false. There is no contradiction here between empirical data and physical explanation given by mainstream climate science. There would be a contradiction, if a linear relationship between CO2 and observed temperature was claimed, and if it was claimed CO2 was the only climate driver that could cause changes in the temperature. No serious climate scientist says such a thing. The temperature record is the result of a combination of forcings from various climate drivers, e.g., greenhouse gases, aerosols, solar activity, land use, plus internal variability in the system. Thus, the speaker's argument is just a straw man argument, which he has repeatedly applied.

Monday, August 20, 2012

What got me snipped from - 2

This time two comments have been vanished from the thread "July was also the 329th consecutive month of positive upwards adjustment to the U.S. temperature record by NOAA/NCDC" at WUWT, either before posting or by deletion after my comment had already been appeared in the thread. Both comments were in reply to comments made by user "Smokey". I don't know why they were vanished. Perhaps, one of the WUWT moderators (e.g., dbs - David B Stealey, h/t Rob Decker) felt my replies may have exposed Smokey's suggestions coming with his comments as embarrassing nonsense.

The first of my comments that got vanished was in reply to a graph posted by Smokey, which he described as the global satellite record of temperature measurements:

----- snip -----

Smokey writes:

USHCN is only the U.S. ["adjusted"] data. But the central question concerns global warming. So let’s look at the global satellite record, which is by far the most accurate temperature measurement.

and gives us following link to look at:

I suppose Smokey shows us this temperature record, which has been derived from satellite retrievals of radiation data by applying mathematical algorithms with assumptions (since satellites do not measure temperatures) to assert that the global temperature has been decreasing over the satellite period.

Smokey is right. There is a negative temperature trend in the lower stratosphere over the whole satellite period. The graph he shows is for the lower stratosphere. The observed temperature change in the lower stratosphere has happened in parallel to the statistically significant positive temperature trend in the troposphere and at the surface over the same time period. The graph shown by Smokey is empirical data, which are consistent with the global warming at the surface and in the troposphere and show what has been predicted. Global warming in the troposphere comes with lower stratospheric cooling. That is the prediction. The data are in agreement with the physical explanation, which attributes those trends to the increasing concentration of greenhouse gases in Earth's atmosphere.

Thank you for showing this, Smokey.

----- snip -----

The second snipped reply was to a comment by Smokey, where he showed a figure with a temperature trend:

----- snip -----

Smokey wrote at August 19, 2012 at 8:52 pm:

Some folks didn’t like my previous chart. So they will probably hate this one.,

referring following link:

Yes, this is totally destroying “the global warming hoax”, isn’t it. /sarc

What about following one?

----- snip -----

On "Perception of Climate Change" in PNAS by Hansen et al.

A new paper has just been published by a team of scientists with James Hansen as lead author in Proceedings of the Academy of Sciences (PNAS) under the title "Perception of Climate Change".[1] The analysis is actually quite straightforward. Taking a reference period (1951-1980), representative for the climate state before the anthropogenically caused global warming of recent decades, assuming a normal distribution of the anomalies relative to the reference period, look at the change in the distribution and the frequency of the occurrence of extreme events, i.e., compare this frequency with the probability that these events would have happened under the climate conditions of the reference period. Doing this for each geographical location on the globe one can produce a map of the probabilities, e.g., for the seasonal average of the temperature, and study their change in time. One can also add up the area of the globe, which is covered by ranges of probabilities, and study by how much this area changes over time.

Events that have a very low probability to occur under the climate conditions of the reference period are of particular interest. Hansen et al. especially look at events that have a lower probability than three times the standard deviation (3-sigma events) of the normal distribution, and the area of the globe which is covered by those events. The probability of the occurrence of events outside of three times the standard deviation is about 0.13% at each tail of the normal distribution, or less than two times in a thousand years for either side. According to the analysis of the surface temperature anomalies by Hansen et al., the fractional area of the globe covered by hot events and by cold events has increased and decreased during Northern Hemispheric summer (June, July, August), respectively. The frequency distribution of the anomalies has become wider, i.e., the variability from year to year has increased over recent decades. The area covered by hot 3-sigma events, i.e., with a very low probability of occurrence has increased from almost 0% during the reference period to a range of 4 to 13% in the various years from 2006 to 2010. Analyzing land surface temperatures only, the fractional area covered by hot 3-sigma events has increased from almost 0% during the reference period to 9 to 21% in the recent years.

So, is the increase in the fractional area of the globe covered by hot 3-sigma events due to anthropogenically caused global warming? I would answer this question with Yes, the results of the study imply that most of the increase in the fractional area is due to it, if one accepts the evidence provided by a whole body of research in climate science that the global warming trend over recent decades compared to the reference period of 1951 to 1980 has been mostly man-made. The scope of the study by Hansen et al., itself is not to provide such evidence. Thus, it does not do that. If one does not accept the evidence from previous research in climate science, but believes in some other cause of the warming, then the metric applied by Hansen et al. would imply that the increase in the fractional area of hot 3-sigma events is due to this other cause.

A possible objection to the analysis that comes to my mind could be regarding the choice of the reference period. The period of 1951 to 1980 appears to be a reasonable choice, if one looks at the globally averaged temperature anomaly (e.g., from the analysis done at the NASA Goddard Institute for Space Studies, see here), since the temperature anomaly had reached a plateau after a previous warming period, although it was somewhat higher in the 1930ies and '40ies. However, is this also true for all the regions of the globe? For instance, surface temperatures in the contiguous United States (CONUS) were about in the same range in the 1930ies as in recent decades. The fractional area of CONUS is less than 1.6% of the globe, but it illustrates the point. Hansen et al. actually checked the robustness of the results from their analysis by looking at selected years of the 1930 and '40ies in the provided supplemental information. The fractional area of hot 3-sigma events goes up to about 3% of the total land surface areas of the globe in some years. This is still only a third or less of the fractional area of the total land surface of the globe, which was covered by hot 3-sigma events from 2006 to 2010.

The central panel of Figure 7 in the Hansen et al., paper shows the graph for the results from the analysis confined to the CONUS area. According to the time series starting in the year 1900 of the fractional area of CONUS covered by "Hot", "Very Hot", and "Extremely Hot" (3-sigma) events shown there, the fractional areas of CONUS covered by these events were about the same in the 1930ies or so as in recent years. Thus, indeed, if one looks only at the United States one can conclude recent heat waves with similar extreme temperatures could also have happened with about equal probability without anthropogenic global warming as backdrop. This also may be true for other regions of Earth due to the occurrence of regional warm anomalies during different time periods. It is still a problem to attribute the occurrence of single events to global warming. However, this misses the point of the analysis as I see it. The point is the simultaneity of the occurrence of extremely hot events at different locations all over the globe, as measured by the fractional area of the globe covered by such events. Extremely hot events can happen here and there also without global warming. But the probability is very low that those events would happen at different locations of the globe all at the same time without the global warming of recent decades.

I have not caught up yet with comments and possible criticism by other climate scientists of the Hansen et al. study. Thus, I am not going to comment here on those.

[1] Hansen, J., Mki. Sato, and R. Ruedy (2012), Perception of climate change, Proc. Natl. Acad. Sci., doi:10.1073/pnas.1205276109.

Sunday, August 5, 2012

What got me snipped from is a website that serves as one of the habitats of deniers of anthropogenic climate change. The website is maintained by Anthony Watts. Misrepresentation of climate science, and personal attacks like defaming, smearing, and libelous accusation of fraud and conspiracy against climate scientists are common. Criticism of such a practice on the blog is not liked as much, and one gets easily snipped by the moderators for such criticism, particularly if the host is criticized.
Thus, I decided to document comments that got snipped. I don't want to have written them for nothing.

Following comment that I submitted was snipped from the thread "Watts et al paper 2nd discussion thread" (with some typos corrected):

----- snip

"kadaka (KD Knoebel):

One full week after the last comment, you tried to slip in The Last Word

How this sounds. I "tried to slip". Like I did something in an secretive way through some backdoor.

Yes, I wrote my comment a week after the previous comment. I hadn't seen the article before. What's the problem? Is there a statue of limitation with respect to the time passed after which a misrepresentation of the results from scientific studies and personal attacks on climate scientists can't be rebutted anymore in a comment?

using an insulting tone from the start:

In the following, you quote some statements as examples, which I made. I just don't see how most of the statements could be reasonably interpreted as "insulting and spiteful".

Let's look at them:

Anthony Watts misleads the audience already in the title of his article:

I stated a fact. I provided an explanation for what the misrepresentation was.

And most of the devote followers here don’t notice or don’t care about being misled. They just want to get confirmed their preconceived views.

In the first sentence, I stated a fact again. If you and Anthony Watts feel insulted by those statements, I can only conclude that you two feel insulted by facts.

The second sentence is my explanation for the behavior of the crowd here. Nothing insulting in the statement.

Although I don’t really understand why the fake skeptics crowd, except the ones who dismiss tree ring proxies altogether, is so excited about this study.

The explanation for the statement followed. I see, though, that there may be people who could feel insulted by my use of the word "fake skeptic", since many here see themselves as part of a heroic resistance against some global and omnipotent evil conspiracy. But that's how I see it. I can't accept the majority here as true skeptics, because the majority doesn't use arguments and approaches true skeptics would use, if they didn't scientifically agree with results from research presented by scientists. Also, no one should expect that my comments here are cheerful after climate scientists like me have been defamed, smeared, insulted, accused of being liars and fraudsters again and again, in thread after thread, like in the mentioned one, often after Anthony Watts has provided the lead, and then in the trail of comments in his echo chamber.

These are the kind of personal, inciting statements, which don’t belong in a scientific argument.

Is this an insulting statement? I don't think so.

But this here is just an opinion blog. Anthony Watts doesn’t do any science. Thus, personal attacks against scientists are allowed.

The real science is done at other venues. It's not done in opinion blogs like this one, where no standards are mandated regarding methodological approach, logic, evidence, or proof of sources. One could try to make an effort to uphold standards of a scientific discussion also in an opinion blog, though, to improve the quality of the blog. But such a thing is not done here by Anthony Watts. He doesn't uphold these standards for himself, and the comment section is even worse."

----- snip

Another comment by me in which I challenged Anthony Watts regarding assertions in another thread he made without providing evidence got snipped as well, from an allegedly "Open Thread". Here it is:

----- snip

I'm still waiting for Anthony Watts to provide the evidence for following assertions, he boldly stated in

Jim Hansen and his sponsor actually did turn the thermostat up in June 1988:

This transcript excerpt is from PBS series Frontline which aired a special in April 2007. Here he admits his stagecraft in his own words:

In the following video, no word by Hansen or evidence of his involvement could be found.

2. directed at me:
The only circular reasoning is yours, courtesy of the taxpayers of the USA.

The surface network is a mess, and by extension so is GISTEMP.

----- snip

Update, Monday Aug 20, 2012: A very ugly smear by Anthony Watts against my person has been brought to my attention by arch in a comment below. Mr. Watts insinuated publicly on his blog that I somehow bear personal responsibility for the tragic passing of Robert E. Phelan, one of the WUWT moderators. The ethics of such a personal attack are discussed here.