Wednesday, December 02, 2015

Ted Cruz Stacks the Deck

Here are Cruz's four witnesses for an upcoming hearing of the Congressional Subcommittee on Space, Science, and Competitiveness, December 8th. Notice a pattern:


Not one scientist from the vast majority of scientists who know the evidence and proof for AGW.

Now imagine if this neo-fascist became president.

The hearing will be streamed live at http://www.commerce.senate.gov.

65 comments:

Unknown said...

Judith Curry is an expert on climate science by any conceivable measure: training, experience, awards, participation on IPCC panels, scientific publications, etc. I'm quite sure she knows the evidence and proof for AGW. As you know, she agrees that the earth has been warming and man has contributed to that warming. However, her judgment is that there's quite a bit of uncertainty, that the true value of climate sensitivity may be fairly low, and that we lack understanding of the impact of natural forces to global warming. Christy is another prestigious expert in climate science who surely understands the climate models.

Happer is a brilliant physicist with a point of view that I happen to agree with. Namely, that the rise and fall of Lysenkoism is a pretty good parallel to the current approach to climate science. Steyn, of course, is no scientist, but he's clever and amusing. I somehow doubt the the lawsuit between him and Michael Mann will ever get to court. But, if it ever does, I have two predictions: Steyn will make it entertaining. And, Steyn will perform better than Mann.

As you say, David, this is a stacked deck of skeptics. I read elsewhere that the Sierra Club was invited to send a representative and declined to do so. I don't know whether any other warmists were invited to testify on Dec. 8.

Cheers
David in Cal

David Appell said...

Ted Cruz only wants one point of view at his hearing. It's outrageous.

Michael Mann knows science. Mark Steyn does not. He has no business at such a hearing; it's only for propaganda purposes. Congressional hearings aren't supposed to be about "clever and amusing" -- they're about experts presenting their views.

Why is Happer a "brilliant physicist?" His views on climate change are not very well thought out, and wrong.

Christy won't even release his computer code or the details of his algorithm. No deniers care, though they made a huge stink about Mann's code. Double standard.

There are many many experts Cruz could have asked to appear. But he's not interested in the actual science, he only wants to hear the ridiculous claim that there's been no warming for 20 years.

Unknown said...

There will be one warmist testifying - David Titley. Wiki says: He was formerly a climate change skeptic, but later changed his mind after looking at the evidence of what factors influence climate--which are, according to Titley, "what are the larger things doing - what is the ocean doing? What is the sun doing? And what's our atmosphere doing?"[3] Since then, he has described climate change as "one of the driving forces in the 21st century" and said that it contributed to the 2011 Arab Spring.[4]

Cheers
David in Cal

David Appell said...

David in Cal: Your moniker of "Unknown" is rude. Choose a nickname (since you are afraid to use your real name) or else.

Unknown said...

I hope Happer doesn't testify on climate models, but rather on the pressure for scientists to conform to a certain narrative. Coincidentally, I just got back from a talk by Professor John Ioannidis at Stanford. As you may know, Dr. Ioannidis has become famous for pointing out the huge percentage of scientific papers with results that could not be reproduced. His talk was in the same vein. He showed how a review of p-values could give an indication of biased research.

He pointed out the motivation. Academics must get grants and publish in order to have a career. Positive, new results are a lot more likely to get published. So, there's a lot of pressure for researchers to manipulate their work so as to get a desired result.

The same is true in climate research. Huge amounts of funding are available for science research showing harmful, man-made global warming. OTOH, coming out against that view can lead to retaliation. Academics without tenure need to be very careful not to advance a point of view that could kill their career.

Cheers
David in Cal

Unknown said...

David, I would be happy to use some name other than "unkonwn", but I'm afraid I do not know how to use this program to do so. I will try to reach my daughter in the next day or two and see if she can tell me what to do.

Cheers
David in Cal

David Appell said...

David in Cal: Learn how to use a real name. Not using a moniker is rude. Last warning.

David Appell said...

Ioannidis's study was almost all about papers in the field of medicine, right?

Does the same reservation apply to Ioannidis's paper -- it is too likely wrong?

If not, why not?

David Appell said...

Unknown wrote:
"He pointed out the motivation. Academics must get grants and publish in order to have a career. Positive, new results are a lot more likely to get published. So, there's a lot of pressure for researchers to manipulate their work so as to get a desired result."

When I see people like you write this, my first thought is that YOUR opinions and work is for sale, so you naturally think everyone's is.

But it's not true. Unlike you, many of us care about the truth and are not willing to sell our views at any price.

In my experience, scientists are the most honest people I have ever met.

Claiming corruption without providing any evidence is cowardly.

David in Cal said...

After almost an hour, my daughter figured out how to get my ID to be David in Cal. I don't sell my views on climate, since I'm retired. Besides, nobody would pay for my views on that topic.

I do believe that scientists are almost all honest. However, according to Ioannidis and to a talk I heard recently by Helena Kraemer, there's lots of bad statistics being done in various fields of medicine and psychology. One suggested remedy is to have a qualified statistician involved in the study design and the data analysis. That's what my wife did, as a bio-statistician. Top medical journals have this requirement. However, a lot of climate statistical work is done non-statisticians, all too often resulting in subtle errors.

Recall that Mann's original Hockey Stick came from a flawed formula that would produce a Hockey Stick shape output from any input. A professional statistician might have helped Mann avoid this embarassing error. Here's a quote from an article that mentions Ioannidis:

Scientists who fiddle around like this — just about all of them do, Simonsohn told me — aren’t usually committing fraud, nor are they intending to. They’re just falling prey to natural human biases that lead them to tip the scales and set up studies to produce false-positive results.

Since publishing novel results can garner a scientist rewards such as tenure and jobs, there’s ample incentive to p-hack. Indeed, when Simonsohn analyzed the distribution of p-values in published psychology papers, he found that they were suspiciously concentrated around 0.05. “Everybody has p-hacked at least a little bit,” Simonsohn told me.

But that doesn’t mean researchers are a bunch of hucksters, a la LaCour. What it means is that they’re human. P-hacking and similar types of manipulations often arise from human biases. “You can do it in unconscious ways —I’ve done it in unconscious ways,” Simonsohn said. “You really believe your hypothesis and you get the data and there’s ambiguity about how to analyze it.” When the first analysis you try doesn’t spit out the result you want, you keep trying until you find one that does. (And if that doesn’t work, you can always fall back on HARKing — hypothesizing after the results are known.)

Subtle (or not-so-subtle) manipulations like these plague so many studies that Stanford meta-science researcher John Ioannidis concluded, in a famous 2005 paper, that most published research findings are false. “It’s really difficult to perform a good study,” he told me, admitting that he has surely published incorrect findings too. “There are so many potential biases and errors and issues that can interfere with getting a reliable, credible result.” Yet despite this conclusion, Ioannidis has not sworn off science. Instead, he’s sworn to protect it.
http://fivethirtyeight.com/features/science-isnt-broken/#part2

One of Helena Kraemer's papers about avoiding a certain class of errors in statistical analysis is at http://eduratio.be/TMP/kraemer.pdf

Ioannidis's famous paper, "Why Most Published Research Findings Are False", is at http://journals.plos.org/plosmedicine/articleid=10.1371/journal.pmed.0020124

Cheers

David Appell said...

David in Cal wrote:
"However, a lot of climate statistical work is done non-statisticians, all too often resulting in subtle errors."

Examples of these subtle errors?

David Appell said...

"Recall that Mann's original Hockey Stick came from a flawed formula that would produce a Hockey Stick shape output from any input."

Says who?

Other researchers have found the same hockey stick result using different mathemetical techniques:

Marcott et al
PAGES 2k
Tingley and Huybers

David Appell said...

"Scientists who fiddle around like this — just about all of them do, Simonsohn told me"

Examples?

Who is Simonsohn?

Does his accusation include himself, or is he the lone exception?

David Appell said...

"They’re just falling prey to natural human biases that lead them to tip the scales and set up studies to produce false-positive results."

Does this also include skeptics and deniers like Christy, Spencer, Curry, Lindzen, Dyson?

David Appell said...

"Recall that Mann's original Hockey Stick came from a flawed formula that would produce a Hockey Stick shape output from any input."

Which formula was that, specifically?

David Appell said...

"Since publishing novel results can garner a scientist rewards such as tenure and jobs, there’s ample incentive to p-hack."

Are you saying Einstein, Feynman and Weinberg lied about their results?

Manabe? Callendar? Plass?

Hubble? Penzias & Wilson?

Revelle? Broecker? Lindzen? Keeling?

Budyko? Schneider? Christy?

Bert Bolin? Spencer?

Who is guilty, David?

David Appell said...

"Subtle (or not-so-subtle) manipulations like these plague so many studies that Stanford meta-science researcher John Ioannidis concluded, in a famous 2005 paper, that most published research findings are false."

Ioannidis's paper was published, righti?

So is it also false?

If not, why is it the exception?

David Appell said...

"P-hacking"

P?

David Appell said...

"When the first analysis you try doesn’t spit out the result you want, you keep trying until you find one that does."

So all published science is wrong, yes?

If not, why not?

David Appell said...

And your biases, David?

What are they?

David in Cal said...

My bias is to be particualarly opposed to bullshit. As an actuary married to a bio-statistician, you can imagine that I'm biased in favor of including qualified statisticians in the study design and data analysis. Statistics looks easy, especially with today's statistical analysis programs, but there are subtleties that a professional statistician would recognize.

As you know, the National Academy of Science had established a committee of statisticians headed by Dr. Wegman to review Mann's Hockey Stick. The Hockey Stick I was addressing was the one reviewed by that committee. One quote from this report:

In most datasets, the first principal component should be the least smooth (because of the higher variance). However, in MBH98, MBH99, the proxy data are incorrectly centered, which inflates the variance of certain proxies and selectively chooses those decentered proxies as the temperature reconstruction....

It is important to note the isolation of the paleoclimate community; even though they rely heavily on statistical methods they do not seem to be interacting with the statistical community. Additionally, we judge that the sharing of research materials, data and results was haphazardly and grudgingly done. In this case we judge that there was too much reliance on peer review, which was not necessarily independent. Moreover, the work has been sufficiently politicized that this community can hardly reassess their public positions without losing credibility. Overall, our committee believes that Mann’s
assessments that the decade of the 1990s was the hottest decade of the millennium and
that 1998 was the hottest year of the millennium cannot be supported by his analysis.


I think that first paragraph means that the incorrect centering produces an artificial hockey stick. Full report at https://climateaudit.files.wordpress.com/2007/11/07142006_wegman_report.pdf

Cheers

Dano said...

Will Christy use his data and what will he say about it? Version 6??

Best,

D

David in Cal said...

David, did your questino mark mean you were asking what P-hacking is? Many journals require a statistical result to meet a 5% confidence in order to accept a paper for publication. Suppose the research yields the desired result, but the p-value is a little short of the 5% standard. The p-hacker re-structures the analysis and finds a way to get the p-value to satisfy the 5% standard.

This practice is hard to detect, because everything looks proper. The new method of analysis would have been valid if it had been used in itially. The mistake is that the analysis method was chosen after the data had been looked at. This is the wrong order. It invalidates the basic assumptions underlying statistical analysis. But, it's said to be a common error.

Cheers

David Appell said...

Dano, good question. I seem to recall that Christy used non-peer reviewed data in a previous Congressional testimony, but now I can't recall the details.

David Appell said...

In any case, it would be fair to ask Christy why he won't share his model's code.

David Appell said...

David: You avoided answering all my other questions.

What evidence do you have that any climate scientist has ever done "p-hacking?"

BTW, there is nothing magical about any particular p value. It's not like a result is true if p=0.049 but false if p=0.051.

David in Cal said...

I didn't mean to claim that any climate scientist had used p-hacking. I just meant to say it's a not uncommon error. I agree that there's nothing magical about 5%. That's just a commonly accepted standard.

I did answer some of your questions. You may have ignored those comments, because they were made as "anonymous". But, I'll give them a quick try:

Examples of these subtle errors? Mann's incorrect centering. Mann's misleading "hide the decline" graph. But, IMHO most climate scientists are doing good work. It's the way their work is publicly reported and promoted that leads to most of the problems. E.g., I think it's very important that the IPCC scientists, in their latest report, were unable to agree on a best estimate of climate sensitivity and were unable to guarantee that the true value lies within their likely range of 1.5 to 4.5 deg C. That means, in English, that although we know that CO2 has an impact on climate, we don't know how big the impact is. Few people know that this is what the IPCC scientists concluded.

Who said that Mann's original Hockey Stick came from a flawed formula that would produce a Hockey Stick shape output from any input? Steve McIntyre was first. He was confirmed by the National Academy of Science committee of statisticians headed by Dr. Wegman.

Which Hockey Stick formula was wrong the one evlaulated by the Wegman Committee.

Am I saying that all science is wrong? Of course not. But, a surprisingly large amount is erronious. Generally, science is confirmed when other scientist repeat the experiment and reproduce the results. Dr. John Ioannidis found that a very large percentage of medical research could not be reproduced. He found large numbers of errors. These led him to write his famous paper. See http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0020124

A writeup said, Ioannidis has been named “one of the most influential scientists alive” by The Atlantic, which also awarded him the Brave Thinker scientist honor in 2010. His thought-provoking article, “Why Most Published Research Findings Are False,” has been the most-accessed article in the history of the Public Library of Science with over 1 million hits. In the talk of Ioannidis that I attended yesterday, he showed how one could deduce a high amount of p-hacking by looking a the distribution of p-values in published papers.

Why is Ioannidis's paper right and others are wrong? Because they are. I mean, there's no magical way to state that all papers are wrong or to automatically say which ones are right. However, when the results can't be reproduced, that's a good clue that something is wrong. My wife has a particular interest in Multiple Sclerosis, because our niece suffers from that disease. She found an error in a paper by Dr. Zamboni on this subject. See http://www.jvascsurg.org/article/S0741-5214(10)01922-1/abstract

What are my biases? I am biased against bullship and illogic. I'm biased in favor of having statistical work done by qualified people. (That shouldn't be surprising, since I'm an actuary and my wife is a biostatistician.)

Cheers

Dano said...

David, you can be sure that the Wingnut Noise Machine will trumpet the denier talking points uttered to Cruz to high heaven. And the WNM will combine that with video of Cruz grandstanding to the Sierra Club to declare warming over.

Best,

d

David Appell said...

David in Cal wrote:
"I didn't mean to claim that any climate scientist had used p-hacking. I just meant to say it's a not uncommon error."

If it's an error, why give it the perjorative label of "hacking?"

David Appell said...

David in Cal wrote:
"Mann's incorrect centering."

Why was that choice of centering "incorrect?"

David Appell said...

David in Cal wrote:
"Mann's misleading "hide the decline" graph."

The graph was clearly labeled. So how was it misleading?

David Appell said...

David in Cal wrote:
"I think it's very important that the IPCC scientists, in their latest report, were unable to agree on a best estimate of climate sensitivity and were unable to guarantee that the true value lies within their likely range of 1.5 to 4.5 deg C. That means, in English, that although we know that CO2 has an impact on climate, we don't know how big the impact is. Few people know that this is what the IPCC scientists concluded."

Why is this a problem, David? That's the conclusion the science allows.

You clearly prefer a conclusion that the science does not allow. You seem to prefer that scientists state some different finding, that the science does not support. Why do you prefer that?

"That means, in English, that although we know that CO2 has an impact on climate, we don't know how big the impact is."

If people don't know what the IPCC wrote, it's because they haven't taken the time to read and learn. Their fault, no one else's.

David Appell said...

"Who said that Mann's original Hockey Stick came from a flawed formula that would produce a Hockey Stick shape output from any input?"

"Steve McIntyre was first. He was confirmed by the National Academy of Science committee of statisticians headed by Dr. Wegman."

WRONG, David. McIntyre published a paper. Wegman -- who it turns out is a plagarist -- gave his thoughts. That doens't mean they are right.

In fact, the several published studies since -- Tingley and Huybers, Marcott et al, PAGES 2k, and more -- come to the same conclusions as Mann et al.

Why are you ignoring these papers, David? I think it's because, as a denier, you are highly biased and only see evidence you think supports your beliefs, and you ignore the evidence that doesn't.

David Appell said...

David in Cal wrote:
"Why is Ioannidis's paper right and others are wrong? Because they are."

Ha. What a foolish answer.

David Appell said...

"I am biased against bullship and illogic."

No you're not. As a denier you are biased against what the science says.

"I'm biased in favor of having statistical work done by qualified people. (That shouldn't be surprising, since I'm an actuary and my wife is a biostatistician.)"

Baloney. Statistics isn't actually that difficult to learn and do. Scientists of the hard scientists are almost all easily smart enough to understand the math -- which isn't that complicated -- and apply it.

You just don't like the conclusions the scientists have come to, so you look for any opportunity to disparage them, even if you have to make up claims without any evidence. That's the ethical low that deniers have come to these days, because they are livid they can't disprove the science.

David in Cal said...

David -- Clearly we disagree on what and who to believe about certain questions. I see no way to resolve these questions here.

Here are a few minor comments, quibbles perhaps.

If [p-hacking] is an error, why give it the perjorative label of "hacking?" Don't understand the question. It seems appropriate to give a pejorative label to an error.

Why was that choice of centering "incorrect?" I am quoting the work of others. It was wrong because
1. It produced artificial hockey stick shape output from any input.
2. National Academy of Science committee said so.

I read the description some years back. As I recall, Mann was using a complex statistical method that required centering. He used a non-standard method to do this. What he did probably appeared to him like an OK modification of the usual approach.

The graph was clearly labeled. So how was it misleading?

1. Because it never should have been included. Instead, Mann ought to have included a consistent graph and pointed out the lack of agreement between tree rings and actual temperatures for recent years, when the actual temperature was known. He should have stated that this lack of agreement meant that his model was uncertain, at best.

2. Because that graph was reproduced elsewhere without the full labeling.

3. Because IMHO that graph was intended to make Mann's model look stronger than it actually was.

4 Because Mann's colleague Phil Jones recognized it a trick to hide the fact that Mann's model didn't match actual temperatures. Jones wrote, "I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith's to hide the decline."

David in Cal said...

(continued from above)
Statistics isn't actually that difficult to learn and do. Scientists of the hard scientists are almost all easily smart enough to understand the math -- which isn't that complicated -- and apply it.

I sympathize with this sentiment. Statistics looks a lot easier than physics or medicine. However, statistics isn't as easy as it appears. Most medical researchers are very smart. Yet, all the top medical journals require a qualified statistician to sign off on the statistical work. Otherwise, they won't accept the paper. Lloyds of London essentially went broke 20 years ago, because non-actuaries were doing the rate-making, which turned out not to be as easy as it appeared.

I think p-hacking is a good example. It's not difficult to learn to use one of the standard statistical analysis programs. But, how many non-statisticians would know they had to avoid choosing a method of analysis that would make the given data show what they wanted. E.g., Mann probably thought his centering method was valid. He obviously chose a non-standard method, because the standard method didn't give him the he wanted.

You just don't like the conclusions the scientists have come to
What I mostly dislike is that much of the public has been misled about the scientific conclusions.

E.g. 1. Dr. Cook did a study purporting to show 97% consensus on global warming. His techniques were flawed, but set that aside. The only consensus he looked at was that the planet has been warming and that man contributes some non-zero amount to global warming. Yet, many people mistakenly think that there's a 97% consensus that man contributes a large amount or a dangerous amount or even a catastrophic amount to global warming.

E.g. 2. Climatologists don't know that much. They don't know what the sensitivity of climate to CO2 is. They don't know how rising temperatures will affect other weather. They know very little about natural causes of temperature variation. Yet, the public is told that this is "settled science."

E.g. 3. The public has been told that global warming causes more general climate change. That's just a theory. There is no consensus about global warming causing more windstorms, droughts, floods, weather extremes, etc. There's no study, not even a flawed one, claiming to show a consensus that global warming will have any of these effects.

Cheers

David Appell said...

David in Cal wrote:
"It seems appropriate to give a pejorative label to an error."

"Hacking" is a pejorative word with the scent of doing something illicit.

An error is a mistake, not done on purpose.

David Appell said...

"Why was that choice of centering "incorrect?" I am quoting the work of others. It was wrong because"
1. It produced artificial hockey stick shape output from any input."

Says who?

"2. National Academy of Science committee said so."

Where? Quote from the citation.

David Appell said...

David in Cal wrote:
"Mann was using a complex statistical method that required centering. He used a non-standard method to do this. What he did probably appeared to him like an OK modification of the usual approach."

Prove it was wrong.

David Appell said...

"Because that graph was reproduced elsewhere without the full labeling."

Where?

How is that Mann's fault?

David Appell said...

""The graph was clearly labeled. So how was it misleading?""
"1. Because it never should have been included."
Instead, Mann ought to have included a consistent graph and pointed out the lack of agreement between tree rings and actual temperatures for recent years, when the actual temperature was known."

Why? He was writing for experts who already understood the divergence problem. His graph used different colors for different lines, clearly showing they were...different.

"He should have stated that this lack of agreement meant that his model was uncertain, at best."

In what way did this lack of agreement mean his model was "uncertain?" Specifically.

The fact is, Mann's model doesn't go past about 1960, BECAUSE of the divergence problem. But his result drove deniers like you so mad that you lie about his what his model actually meant and where it applied.

David Appell said...

"3. Because IMHO that graph was intended to make Mann's model look stronger than it actually was."

This shows you didn't understand Mann's work, while lots of others did. Your fault, not his.

David Appell said...

David in Cal wrote:
"What I mostly dislike is that much of the public has been misled about the scientific conclusions."

What I don't like is you lying like this.

You distort the science, and then blame scientists for that distortion. You should be ashamed of yourself.

David Appell said...

I couldn't care less what John Cook said, and have said so on this blog.

In any case, the agreement on consensus is over 99%:

http://cleantechnica.com/2015/07/31/human-climate-link-still-97-nope-99-video/

"E.g. 2. Climatologists don't know that much. They don't know what the sensitivity of climate to CO2 is."

David -- this is your last warning. If you do not stop lying like this, all of your subsequent comments will be immediately deleted.

Got it?

"They don't know how rising temperatures will affect other weather. They know very little about natural causes of temperature variation."

So tell us, David, in your expert opinion as an actuarial, what are the natural causes of global warming that climate scientists are overlooking?

"E.g. 3. The public has been told that global warming causes more general climate change. That's just a theory. There is no consensus about global warming causing more windstorms, droughts, floods, weather extremes, etc. There's no study, not even a flawed one, claiming to show a consensus that global warming will have any of these effects."

Bullshit. A more energetic system has larger fluctuations -- that's basic thermodynamics.

Did you ever study thermodynamics, David?

David in Cal said...

David, which science do you claim I distorted?
Cheers

David Appell said...

David in Cal wrote:
"Because Mann's colleague Phil Jones recognized it a trick to hide the fact that Mann's model didn't match actual temperatures."

You are really scrapping the shit off the bottom of the barrel now, aren't you.

Do you know what the word "trick" means in science, David? No, of course you don't.

It means a clever idea.

That's all. Liars like you are distorting this for your own ends because you cannot compete on the science. It's dispicable.

David Appell said...

"David, which science do you claim I distorted?"

Read my comments above.

David Appell said...

David in Cal wrote:
"I sympathize with this sentiment. Statistics looks a lot easier than physics or medicine. However, statistics isn't as easy as it appears. Most medical researchers are very smart. Yet, all the top medical journals require a qualified statistician to sign off on the statistical work. Otherwise, they won't accept the paper."

Physical scientists are a lot better at math than medical researchers.

Sorry to burst your self-centered bubble, but statistics isn't that difficult to learn. Or to do. Physicists are very smart and very good at math, and statistics is just applied math.

And there isn't even that much of it, because doing climate research is fundamentally different from doing medical research -- it's an observational science, not an experimental science. Climate scientists don't set up a sytem in a controlled/initial state and see what changes. There is only one Earth, so that is impossible. So, in fact, you see very few p-values quoted in climate science, because that simply isn't how data in an observational science is done.

David in Cal said...

David -- It's conceivable that Dr. Jones was using the word "trick" to mean "clever idea", rather than its main definition, "a crafty procedure or practice meant to deceive or defraud." However, if you're right, the question arises, What is it that was clever about Mann's mixing of graphs?

The only cleverness I saw was to make it harder to see that the tree rings didn't match recent temperatures. If your interpretation is correct, then there was a scientifically valid clever reason to splice the graph in this way. What was that reason?

David Appell said...

David in Cal wrote:
"It's conceivable that Dr. Jones was using the word "trick" to mean "clever idea""

Why is it inconceivable?

David Appell said...

David in Cal wrote:
"It's conceivable that Dr. Jones was using the word "trick" to mean "clever idea""

David: I've taken a lot more science courses than you have, and math courses, and listened to a lot more seminars, colloquia, and talks than you, and talked to a lot more scientists.

Innumerable times I've heard the word "trick" used to mean "a clever idea."

Are you calling me a liar?

David Appell said...

David in Cal wrote:
"The only cleverness I saw was to make it harder to see that the tree rings didn't match recent temperatures."

That reflects your inability to understand the science.

Scientific papers aren't written for amateur like you.

"If your interpretation is correct, then there was a scientifically valid clever reason to splice the graph in this way. What was that reason?"

Because the model's conclusions about some tree rings after about 1960 weren't valid because of the divergence problem:

“On the ‘Divergence Problem’ in Northern Forests: A review of the
tree-ring evidence and possible causes,” Rosanne D'Arrigo et al, Global and Planetary Change 60 (2008) 289–305.
http://www.ldeo.columbia.edu/~liepert/pdf/DArrigo_etal.pdf

David Appell said...

http://www.skepticalscience.com/Mikes-Nature-trick-hide-the-decline.htm

David Appell said...

David in Cal wrote:
"...the question arises, What is it that was clever about Mann's mixing of graphs?"

It put all the information on one graph.

Scientific papers usually strive to be concise. Page space, page charges, general scholarship, and all that.

Again, these papers are written for professionals, not amateurs. Watson and Crick's famous paper on the structure of DNA spanned only two pages, and was barely a single page long in length:

http://www.nature.com/nature/dna50/watsoncrick.pdf

David in Cal said...

Are you calling me a liar? No, indeed. I said is wasconceivable that the word "trick" was used as you believe it was. BTW I tend to doubt that you've taken more math courses than I. I spent 5 years as a math grad student at Berkeley. I am a kind of scientist, if you call Actuarial Science a science. My bistatistician wife of 50 years is a real scientist. She co-authored over 100 papers in scientific journals. So, I too am familiar with how mathematicians and scientists talk.

David in Cal said...

REviewing your comments, David, I see that my statement that your interpretation was conceivable was misread as if I had written "inconceivable".

On reflection, Mann didn't put all the information on one chart. In fact, what was noteworthy was that the chart omitted a key bit of information-- namely, what his tree-ring model would have shown for recent years. IMHO a better chart would have shown both series: measured temperature for recent years and modeled temperature for recent years.

Cheers

David Appell said...

"I said is wasconceivable that the word "trick" was used as you believe it was."

You're wrong and don't know what you're talking about. When are you going to admit it?

http://davidappell.blogspot.com/2009/11/word-trick.html

"So what is "Mike's Nature trick"? This refers to a technique (in other words, "trick of the trade")...."
https://www.skepticalscience.com/Mikes-Nature-trick-hide-the-decline-advanced.htm

"Regarding the “hide the decline” email, Jones has explained that when he used the word “trick”, he simply meant “a mathematical approach brought to bear to solve a problem”."
http://www.skepticalscience.com/Climategate-hide-the-decline.html

David Appell said...

A statistician who understood the word "trick" as used by Jones:

http://is.gd/ZAbrds

https://books.google.com/books?id=g_S_AwAAQBAJ&pg=PA302&lpg=PA302&dq=the+word+trick+in+science&source=bl&ots=2kKPuv_df0&sig=Ai6MvrcfwmHAJHnuo9X_lNReluQ&hl=en&sa=X&ved=0ahUKEwjN96mkg8jJAhUFoYMKHT7ABu4Q6AEITzAM#v=onepage&q=the%20word%20trick%20in%20science&f=false

JoeT said...

David Appell,

Did you watch the hearing today? I wasn't able to so I was hoping that you might say a bit what you found interesting (or not so interesting, as the case may be).

I can't even find online a recorded video of the hearing. Does one exist that we can still watch?

[uggh, if I have to read one more boring objection to Michael Mann's reconstruction I'm going to puke. Seriously, principal component analysis is not that difficult to understand]

David Appell said...

Joe: I wasn't able to watch today's hearing, but have tried to catch up via Twitter.

Eli live-blogged it here:

http://rabett.blogspot.com/2015/12/senate-hearing-live-blog.html

David in Cal said...

Joe T - you can find 5 1/2 minutes of Mark Steyn's comments on a video at https://www.youtube.com/watch?v=bTM13sI2BFQ

Cheers

David in Cal said...

Joe T. and David Appell -- This looks like the entire hearing on You Tube https://www.youtube.com/watch?v=5KVTmo2Vxnk

Cheers

JoeT said...

David in Cal,

Thanks for the link. I appreciate it.

Since you seem like a reasonable person (in some ways), I'll throw in my 2 cents about Mann's paper. You can respond if you like, but I won't since I pretty sick of this subject myself.

You should actually read the Mann paper. You can find a copy of it somewhere on the internet that is not behind a paywall. You'd be surprised as to what the paper is actually about. Mann's intent was not to show the world a hockey stick. He didn't need to do a principal component analysis to do that. He could have merely showed the data and that would have been sufficient. What he was actually interested in was unraveling the natural patterns in NH climate. That's the reason for the PCA. We use it in plasma physics to reconstruct plasma equilibrium. It's been a while since I read the paper, but from memory he was interested in looking at things like ENSO and the North Atlantic Oscillation.

When you do a PCA you get a set of eigenvalues that correspond to a set of eigenfunctions. Using his centering the warming component was the first and therefore the largest eigenvalue. There is a criteria for how many eigenvalues you should use in the reconstruction. The essential point is that when you do the full reconstruction you should get very close to the original data that you started with.

What M&M (McIntyre and McKitrick) did was to change the centering. What that does is change to order of the eigenvalues. The warming component is still there, but it's not longer the largest eigenvalue. M&M simply threw it away, which is nothing less than fraud.

David Appell said...

David in Cal wrote:
"IMHO a better chart would have shown both series: measured temperature for recent years and modeled temperature for recent years."

That's your opinion. Mann had a different opinion.

Having a different opinion does not mean Mann committed fraud.