David Burton writes:
I just realized the obvious answer to a question that has been nagging in the back of my mind for nearly a year and a half.
In 2008 Margaret Zimmerman asked two questions of 10,257 Earth Scientists at academic and government institutions. 3146 of them responded. That survey was the original basis for the famous “97% consensus” claim.
For the calculation of the degree of consensus among experts in the Doran/Zimmerman article, all but 79 of the respondents were excluded. They wrote:
“In our survey, the most specialized and knowledgeable respondents (with regard to climate change) are those who listed climate science as their area of expertise and who also have published more than 50% of their recent peer-reviewed papers on the subject of climate change (79 individuals in total). Of these specialists, 96.2% (76 of 79) answered “risen” to question 1 and 97.4% (75 of 77) answered yes to question 2.”
The basis for the “97% consensus” claim is this excerpt:
[of] “the most specialized and knowledgeable respondents (with regard to climate change)… 97.4% (75 of 77) answered yes to question 2.”
But that is a false statement.
The two questions were:
Q1: “When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?” 76 of 79 (96.2%) answered “risen.”
Q2: “Do you think human activity is a significant contributing factor in changing mean global temperatures?” 75 of 77 (97.4%) answered “yes.”
My nagging question was, why did different numbers of people (79 vs. 77) answer the two questions? What happened to the other two respondents?
The answer to that question is not in the Doran article.
But it is in the Zimmerman report, a copy of which I bought back in March, 2012. The reason I feel stupid is that I read it and even quoted the relevant part way back then, and it still took me until now to realize the obvious answer to my nagging question.
This was the full set of questions that Zimmerman asked in their survey:
Q1. When compared with pre-1800's levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?1. Risen2. Fallen3. Remained relatively constant4. No opinion/Don't knowQ2. Do you think human activity is a significant contributing factor in changing mean global temperatures? [This question wasn’t asked if they answered “remained relatively constant” to Q1]1. Yes2. No3. I'm not sureQ3. What do you consider to be the most compelling argument that supports your previous answer (or, for those who were unsure, why were they unsure)? [This question wasn’t asked if they answered “remained relatively constant” to Q1]Q4. Please estimate the percentage of your fellow geoscientists who think human activity is a contributing factor to global climate change.Q5. Which percentage of your papers published in peer-reviewed journals in the last 5 years have been on the subject of climate change?Q6. AgeQ7. GenderQ8. What is the highest level of education you have attained?Q9. Which category best describes your area of expertise?
Do you see it? If a respondent answered “remained relatively constant” to the first question, then he wasn’t asked the second question!
That’s obviously why only 77 answers were reported to the second question. Two of their 79 top climate specialists had answered “remained relatively constant” to the first question, and those two were not asked the second question, and were not included in the calculation of the supposed 97.4% agreement.
That means only 75 of 79 (94.9%) of their “most specialized and knowledgeable respondents” actually gave them the answers they wanted to both of their questions.
So, despite asking “dumb questions” that even most skeptics would answer “correctly,” and despite excluding over 97% of the responses after they were received, they still did not find 97% agreement. They actually found only 94.9% agreement.
I’ve updated my http://tinyurl.com/Clim97pct page to reflect that fact.
I’ve also emailed the editor of Eos, which published their article back in 2009, asking that they run a correction.
Re: An oopsie in the Doran/Zimmerman 97% consensus claim
Drilling down:
1. 1/1 Recent (respondent-provided) peer-reviewed papers on climate change = 100%, a sufficient publication record (> 50%) to be counted among “specialized and knowledgeable respondents”.
2. 3,067/3,146 Earth Scientists = 97.4% not admitting to being published Climate Scientists.
3. 7,111/10,257 Earth Scientists = 69.3% thought the survey was not worth answering at all.
4. 3/79 Climate Scientists = 3.8% unaware of the Little Ice Age
5. 75/10,257 Earth Scientists = 0.7% thought that human activity had enough of an effect on Earth’s mean global temperature to make the survey worth answering. (Accord Rob @ur momisugly 11:06 am, above.)
“Do you think human activity is a significant contributing factor in changing mean global temperatures?“. What does “significant” mean? I suspect that most people would have “significant” begin at around 10%. Even with “significant” beginning somewhat higher than that, virtually all those who are sceptical of mainstream climate science, because they think that the AGW effect has been exaggerated, would answer “yes” to that question.
That’s very interesting to see the full story & well spotted there David. The same thing had occurred to me in May when looking closer at the paper , about the actually being 95% http://joannenova.com.au/2013/05/cooks-fallacy-97-consensus-study-is-a-marketing-ploy-some-journalists-will-fall-for/?replytocom=1274625#respond
It’s great to understand why now too, from all your enquiries.
Harold Ambler says:
December 10, 2013 at 8:03 am
I personally made the Sun rise this morning. And this had never happened before.
Thank you Harold. Very kind of you to do this for us all…and our children…../ sarc lol
We all know the 97% figure is bogus, the problem is that there are far too many second rate politicians and scientists who think it is gospel.
This 97% figure is all too often is used as an excuse for implementing economically damaging ‘climate change’ policies. The problem is – as shown several times here – is that its obviously fatal flaws take a little too long to explain for the comfort of the average individual’s attention span.
97% is the magic consensus number. The 3% doubt-there is always one or two who do not agree. As people would know some of the dissenters, 100% would be an obvious fraud. If it were 98%, it would look too contrived-it would not be believable. If it were 96%, it would not be regarded as conclusive. I will bet that the next climate assessment will claim 97% certainty that man-made CO2 causes global warming or climate change, regardless of the actual growing disparity between measured results and model predictions. Maybe we can take a poll of what the poppycock excuse will be to explain away where the excess heat went when the discrepancy rises. The distribution to the ocean depths to an immeasurable degree has already been (ab)used.
How about a paper to dispel this poppycock.Perhaps a physicist demonstrating the heat would persist in the upper oceans for too long to explain the miraculous heat loss and measuring constraints make the theory invalid.
95% of those who call themselves climate scientists are actually marxist propagandists.
Which of these experts said no? Even I would say yes despite UHI etc. Little Ice Age.
[My emphasis] Now this is a tricky one. Does human activity include UHI, land use changes, soot? Why didn’t they substitute “human activity” for man-made greenhouse gases?
7,111 Earth scientists could not be bothered to respond. They obviously don’t think man-made greenhouse gases are a problem enough to bother responding about.
Of the 79 it would be interesting to know where they get their funding from. Seventy-nine turkeys were asked to vote for or against Christmas. There was a 100% consensus to ban Christmas.
I’d originally thought the D&Z paper to appear at least ‘plausible’ in the minds of the authors, notwithstanding the fatal flaws and inherent bias that they might fail to see in their selection methodology.
But now we can see from David’s revealing the full report that it was actually nothing but fraudulent.
The climate looks like it is 97% consensus changing, and this was always the joker in the pack. 😉
PS The consensus survey papers are just a pack of horse poop. What if you have a consensus that is shown years down the line to be wrong? I feel an stomach ulcer coming along.
I note that the questions asked in these surveys seem rather innocuous and leave all sorts of wiggle room. When the results are published is when the wild exaggerations and claims of calamity appear. No one ever asks THE question to wit : ” Is all of the alleged warming of the earth the fault of the burning of fossil fuels and CO2??” The reason for that is they don’t want to go on record as being obvious crackpots (or as our friends in the UK would say “barking mad”). The wild claims and accusations are left to those who do not have a scientific bone in their bodies — The journalists, the dyed in the wool leftists, the politicians, and the other liars like algore. I may not be talking about separate groups here.
This is the part I have trouble with.
Where’s the catastrophe questions?
People won’t fear AGW if there is no “C” in front of it.
Has there ever been a survey establishing the “catastrophe consensus?”
Where’s the questions asking:
Do you believe CO2 will boil the oceans and burn the earth?
Do you believe we can control the climate by regulating CO2?
Do you believe we need a category 6 for hurricanes because of CO2?
Do you believe malaria is on the rise due to CAGW caused by CO2?
At current rates, how much will the sea level change by 2050?
Let’s call ourselves “the three-percenters–the happy few.”
Actually, since the physically meaningless metric, “mean global temperatures” (There’s that ridiculous plural again. there is no global temperature, and definitely not multiple global temperatures) is a completely man-made thing, the answer should have been 100%.
To maximize their “consensus” number, Zimmerman & Doran:
1. Chose to survey only scientists at academic and government institutions (which generally lean Left), and
2. Asked “no-brainer” questions that almost everyone, even climate skeptics, would answer “correctly,” and
3. Did not ask any questions that would actually separate alarmists from skeptics, such as whether, in President Obama’s words, “climate change is real, man-made and dangerous,” and
4. Used only 79 out of the 3146 responses that they received, when calculating their degree-of-agreement percentage. They called those 79 “the most specialized and knowledgeable respondents (with regard to climate change).”
They reported that 75 of the “most specialized and knowledgeable respondents” agreed with the “consensus” position that “mean global temperatures have generally risen” (since the depths of the Little Ice Age!) and “human activity is a significant contributing factor in changing mean global temperatures.”
Note #1: by that measure, even I am part of the consensus.
Note #2: They concluded that, “It seems that the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes.”
Note #3: Their methodology could easily be used to reach the conclusion that “the debate on the authenticity of acupuncture is largely nonexistent among those who understand its nuances and scientific basis.”
But all that was insufficient. 75 of 79 is not 97%, it is only 94.9%.
So how did they get 97%?
The answer is that they simply didn’t count the two “most specialized and knowledgeable respondents” who had said they thought global temperatures “remained relatively constant.”
79 – 2 = 77, and 75 / 77 = 97.4% = mission accomplished.
On that basis they reported in the prestigious journal Eos, Transactions, American Geophysical Union, that:
I marvel that such an obvious blunder could get past peer review, or even pal review.
” I marvel that such an obvious blunder could get past peer review, or even pal review. ”
Peer review vested in interests ( Or is that interests vested in peer review ? )
” I marvel that such an obvious blunder could get past peer review, or even pal review. ”
Peer review vested in interests ( or is it interests vested in peer review ? ).
I don’t see much point in quibbling whether the number is 95 or 97, the whole exercise is so flawed as to be meaningless.
Q2: “Do you think human activity is a significant contributing factor in changing mean global temperatures?” 75 of 77 (97.4%) answered “yes.”
What does ‘significant’ mean? It could mean anything you like. Suppose I believed human activity caused a 0.1 degree rise. If I happened to believe 0.1 degree to be significant, then I would answer yes. You simply can’t let the person answering the survey decide what ‘significant’ means, it has to be clearly defined.
The obvious solution would be to ask what amount of warming was caused by humans, in one tenth of a degree values ranging from zero to 1.0.
I would answer either zero or 0.1 – and I certainly wouldn’t regard it as ‘significant’.
Chris
Indeed, is pee’er review merely a matter of territorial defence.
” Kevin and I will keep them out somehow – even if we have to redefine what the peer-review literature is ! “
What’s the consensus purity of the 79 scientists? It says part of the criteria for selecting the ‘top’ scientists were those that were peer reviewed. Didn’t the climategate emails shows a definite bias or exclusion of those that disagreed with global warming? Doesn’t that make the 79 chosen scientists pro global warming anyway? That sounds like asking the most fanatic Steelers fans who the greatest team is and then concluding 97% of football fans say the Steelers is the greatest team!
“Q8. What is the highest level of education you have attained?”
And when did you attain it? In the Golden Age of Climate Science (GACS)? Or before Before Academic Corruption of Climate Science (BACS). Asterisk required for former on scientific papers.
I sent the survey to my oldest brother a semiretired Ph.D. professor emeritus who taught, among other things, Research Methods. His comment:
“The survey is lousy. Whoever wrote this article is biased. “
The “article” referred to is the linked PDF article.
The standard of ‘evidenced ‘ for the 97% claim is equal to the standard of evidence to the claim nine out of ten cat prefer Whiskers cat food . For in both cases the actual total number of cats and scientists is a total unknown. therefore its impossible say what percentage this sub group are of the whole group . However in both cases you could take a guess that their dam site more cats or scientists that give no answer at all and that there is no honest way can use the views of this tiny sub group as a honest representation of the whole group.
But a t least if a cat craps in your garden you their not going to lie about it , climate ‘scientists’ on the other hand are another question.
I think it’s coined by this:
“Paul Homewood says:
December 10, 2013 at 9:03 am
75 scientists say the science is settled!”
The 97% consensus is based on only 75 people out of 10.257?
Why haven’t the journalists been all over this by now?
We have a none working climate science and a no working critical journalism.
Or it has all been politicized?
By in large, the American media is far, far left and HAS been for AT LEAST 50 years or so. Remember how they piled onto Joe McCarthy and drove him to drink himself to death? Well, turns out that McCarthy was RIGHT all along. Remember how Cronkite pronounced the 1968 Tet debacle as a “victory” for the VC and proof that they couldn’t be defeated? It was a “victory” in which they took 60% casualties to their fighting forces, didn’t win a single battle or take control of a single acre of South Vietnam for more than 2 days before being driven out. “Uncle” Ho was ready to quit until his Soviet advisors told him to hold on and the American media would fight his battles FOR him. They were right. EVERY anti-war group in the country was ultimately financed by the KGB and the press KNEW it…but kept silent. Look what they’re doing even today.
Is this article Poe?
The complaint is that a paper published nearly 5 years ago says 75 out of 77, when it should say 75 out of 79?
Really?
It’s no big deal Really. Just fascinating to watch the lengths one will go to, this last being but a previously undiscovered pinnacle, on top of all the other selective measures, to overwhelm in a scientific presentation.
Seriously, orion? This is a science blog. The math matters. It should bother you that in a prominent peer-reviewed journal the authors of a very, very widely cited paper about how many dissenters there are from the global warming “consensus” simply didn’t count half of the dissenters that they found.
There are only two possibilities:
1. it was an unintentional blunder, and they really didn’t know better than to do what they did. In that case, how could you possibly trust the competency of anything they (or their peer reviewers!) do? Or else,
2. it was intentional deception. In that case, recall Luke 16:10.
Which do you think it was, orion?
More fundamentally, the truth matters. Scripture calls lies the devil’s language. If you don’t think so, then that probably explains why you toss off insults directed at scientists who work intensely to discern the truth, and why you apparently aren’t bothered by things like Climategate, Gleick’s forgery-based Heartland smear, Mike’s Nature trick, etc.