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.
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The bigger question I have always had (but know the answer) is why did they send the poll to 11,000 scientists when by their own methodology they only planned to use 2.5% of them?
Answer: They didn’t like the outcome of the full poll and whittled it down until they got the number they wanted.
They asked if they think that temperatures have risen since the mid 1800s. It is almost inconceivable to think that someone would say no. On the other hand, if they asked have temperatures risen since the 1930s you certainly would get a larger number of respondents saying that the answer to that question is not 100% clear. Especially if you look at the United States, where it seems likely that temperatures have actually dropped since the 1930s. Worldwide? That’s another question.
I would like to see the answers from the “specialized and knowledgeable respondents”, to Q3:
“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)?”
How many “compelling arguments” where presented, and how many just left it blank, or regurgitated the “we can’t afford to wait” talking points. I wonder how “compelling” those arguments are today?
What the respondents to the survey really says is that of the scientific community, only 77 made it very clear that they are not scientists. However, 33,000 made it very clear they are scientists.
Back when I was still doing research, we considered any signal that was measureable as significant, even if we had to use a boxcar integrator to find it. The term ‘significant’ has different meanings, and is dependent on the person using the term.
Total Earth Scientists (ie people that might notice change in the earth due to climate) = 10257
Percentage that felt it important enough (or qualified enough) to answer poll = 3146 = 30.7% (less than a 1/3rd of scientists)
Percentage that were subjectively allowed (screened) to answer = 79 = 0.77 % of total earth scientists, or 2.5 % of those that felt qualified to answer. (basing this on a science professional would answer only if they felt qualified)
Those that felt AGW is real = 2.38% of those who both felt it necessary to answer and allowed to answer. Or 0.73% of total earth scientists.
Raving Concensus
Straining out a gnat (a few % points) and swallowing a camel (the fundamentally wrongheaded study).
Nice article. Nice to know someone has got the numbers right.
Q1 can be rephrased:
Has it been warming or cooling since the 1800s?
Most would say definitely. Maybe more or less than 0.1F, but definitely, yeah temp has changed.
Q2: rephrased:
If something has happened since the 1800s, do You think mankind had something to do with it?
Most would answer, Yes, definitely. Mankind has become a major ecological force since the 1800s. So it is only fair to believe some of our activities has had an impact.
But those who answered were not asked the questions the media claims were asked:
Q1 rephrased:
Has there been a temp increase since 1800?
Q2 rephrased:
Is mankind the most important factor in this temperature rise, through our emission of CO2 from burning fossil fuel?
The public, however, do believe that these were the questions, not those in my 1st rephrasing.
The surveyed were not asked if it has become warmer. Q1.
The surveyed were not asked weather they believe we contributed to 50% or more of the warming, as has been claimed. Is 1% significant? Maybe. Is 3% significant. Maybe. Is more than 50% significant, definitely.
So why not ask that question flat out: If You do think that there has been a rise in temperature, what potion of this increase has, in Your opinion, been caused by humans?
a) 75%, b) 50% c) 25%, d) 10%, e) 5%, f) less than 5%, g) I am not sure.
They did not ask this or any similar question, and as 1% can bee seen as significant, those who answered could have implied, mankind was responsible for 1% of the warming.
This survey then, is not statistics, and it is not science. It is not precise, it does not ask or answer any of the things the media has puffed it up to do. Anything significant arising out of this survey, can be dismissed totally as propaganda, not science, not precise, and not worthy of any statistical analysis.
I am going to respectfully disagree:
From the pdf file in the survey link above:
Also
Finally,
Now, I understand that these two government-paid “researchers” eliminated all replies (of those who were NOT employed at government institutions, accepting the prejudiced argument paraphrased as: “Any private money paid to researchers from private enterprise or from non-government institutions corrupts the results of that research, and therefore (the replies from non-government scientists) cannot be reported nor analyzed seriously by us in our paper. Government-paid “scientists” are NOT prejudiced nor can they be corrupted by the source of their (government-paid) grants and salaries and funding.”
Notice also that the “participants” ARE specifically mentioned as including skeptics, the 79 chosen “ANSWERS” to these two simplified questions do NOT include any skeptical replies. Those have been eliminated by requiring that 50% of the person’s “recent papers” be on “climate science”. ANY person who writes articles on well-rounded subjects has been eliminated. Notably also, since government-paid grants ARE the sole funding for “climate science” limited research topics, by requiring that 50% of a person’s recent papers (note the unclear criteria of “recent papers” as well!) these two propagandists further their methodology and prejudices.
For reference, 5% of 3146 replies is only 157 answers.
8.5 % of 3146 replies is only 267 people.
Assuming nobody deliberately circumvented the rules and answered two or more times. So, we could immediately and accurately claim that only 77 out of 267 (29% of “scientists”) VERY ACTIVE IN ACTUAL CLIMATE SCIENCE PEER_REVIEWED RESEARCH believe in their theory of man-caused temperature increases due to man’s release of CO2 into the atmosphere!
As others have noted, this poll was rigged from the start:
“…Margaret Zimmerman asked… 10,257 Earth Scientists… 3146 of them responded. …all but 79 of the respondents were excluded.” (because they weren’t climatologists).
Enough said. It’s crystal clear the only reason Earth Scientists (other than climatologists) were on the mailing list was to give the survey the appearance of legitimacy. They screened out everyone who wasn’t a climatologist because they didn’t want to know what real Earth Scientists believe. Remember, this BS was published in EOS, (the Journal of the American Geophysical Union) while Peter Gleick was head of the AGU task force on Scientific Ethics. No journal worth the paper it is printed on would publish such a blatantly skewed survey.
Any guesses as to who the two ‘denier’ climatologists were? My guess is Judy Curry and one of the Roger Pielkes
pappad says:
December 10, 2013 at 10:11 am
Anybody care to explain to me how CO2 can allow IR to REACH the surface but somehow “traps” it there and won’t allow it to reflect back into space??? Is it one-way reflective?
I would go a step further and ask the question –
Isn’t the altitude of the CO2 molecule important also since the earth’s surface is round and curves away from the emitted radiation?
There are 38 “notable” scientists alone on this list:
http://en.wikipedia.org/wiki/List_of_scientists_opposing_the_mainstream_scientific_assessment_of_global_warming
who go against the grain of “the science is settled” crowd. How many of these were part of the 79 who did the survey from where the 97% consensus was established?
Post 1990 climatologists are corruptly biased toward warmism
Here’s a counter-intuitive point. Doran tried to narrow it down to those most actively involved with climate change, as climatologists with the most published papers. From what I can sense and gather, the problem is that climatologists of the post ~ 1990 vintage were not admitted into their doctorate programs unless they agreed with science and preferably politics of the (leftist) Chicken Littles like James Hansen. So, any survey of post 1990 climatologists (of which most of them are) will find almost unanimous agreement with warmist “science” and goals.
The Hockey Schtick reports: Meteorologist’s poll finds no consensus on climate change & those with liberal political views far more likely to believe in man-made global warming. Only 52% overall believed global warming is happening and is mostly human-caused, while 48 percent did not. But they looked at those who “earned their living” via global warming, and found that to be a conflict of interest (instead of a positive and appropriate “specialization” or whatever), and reported how these respondents were biased toward the warmist position.
In my opinion, this whole exercise starts off with the logical fallacy of “begging the question”; i.e. “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).”
How did they determine that the chosen subgroup was the most “specialized and knowledgeable”?
(As to the former, I see climate scientists as generalists, not specialists.) If they tested “knowledgeable” by how they conformed to the current consensus, then the argument is indeed circular.
If the purpose of the poll was to study the opinions of published self described “climate scientists”, a group which turned out to be only 79 (or 77) members, why was it necessary to mail out the survey to over 10,000 scientists? Sure, not everyone responded, but Zimmerman still had a pool of over 3,000 respondents to pick from. Does this even make sense? If you were really interested in the religious opinions of, say, Jesuits, would you send out survey forms to 10,000 different ministers, priests and practitioners from all major religions — and then just pick out the answers from responding Jesuits? No, of course not.
Oh well, if it were an actual scientific survey they would not have used such ambiguous questions anyway. As many others have commented, the questions are so poorly phrased that most sceptics would have answered the same as the so-called experts.
97% or 94%, who cares? Sure, the study is crap anyway but the difference in percentages is insignificant.
…and yet a 0,07 degree increase in global temperatures over a 100-year period IS “significant?”
sorry for the decimal error. I’m having cataract surgery and things aren’t too clear on-screen these days.
Humorous thought of the day: In a few years, when CAGW is generally accepted as scientific fraud, some bright MSM reporter will “discover” how the 97% number was actually generated, providing yet another obscene example of how devious scientists defrauded the general public.
By that time, scientific credibility might be pretty well shot…the world will once again fill with astrologers, alchemists, palm readers and homeopathic witch doctors.
ps: I agree with previous Streisand effect comments – we don’t need MSM headlines saying “Even Deniers Think 95% of Scientists Agree…”.
Margaret Zimmerman sent survey to “Earth Scientists at academic and government institutions”, thus she had already picked “most specialized and knowledgeable respondents” for survey. In essence the survey started with bias. Margaret Zimmerman’s survey further tossing out 3,067 respondents amounts to cherry picking. Which makes whole 97% to 95% claim unscientific (aka bogus).
An honest survey/summary would acknowledge non-cherry picked result would amount to consensus of only 2.4%. To solely claim 97% is another example of constant misleading, unethical, dishonest, and/or unscientific, claims and results by proponents of Global Warming.
Almost 100% of scientists agreed at one point (in fact for almost 1000 years) that the Sun revolved around the Earth. That’s the best argument that consensus means nothing.
It would be difficult to list all the ways this study is meaningless. Over 10,000 scientists were asked. How were they chosen? Just over 3,000 responded. So already we have a self-selection problem.
After applying a subjective and (perhaps defensible but nevertheless) arbitrary set of filters, we examine the responses of 79. So a completely unscientific process is used to select a group representing 0.8% of the original group (itself chosen in an unscientific manner) and that 0.8% is allowed to speak for everyone in order to create an argument by authority.
Humm!
Q2. 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. Yes
2. No
3. I’m not sure
Since it is not the penguins that are manipulating the global temperature data, then you HAVE to answer YES.
It’s shocking but true, 75 doctors (out of 3,146) agree that brushing your teeth with brand x is better than brand y. And if you don’t agree to buy into our product, we will label you and blacklist you for life. Happiness and world peace be with you.
Heck, it’s just a minor technical ‘glitch’ (fashionable word these days) in their statistics. I have little doubt, that when it comes to the much more challenging, daunting, borderline impossible, statistical problem of determining a current global average temperature coupled with the even more daunting, virtually impossible, statistical problem of computing past global average temperatures and then detecting a change that these people are more than up to the challenge.
Ok, I better type this: (sarc).
Hell, that must be unprecedented all right.
TomL says:
December 10, 2013 at 8:44 am
The first question was trivial. 1800 was in the midst of the Little Ice Age, so OF COURSE it’s warmer now.
Even so, of these supposed knowledgeable “climate scientists”, there was not 100% agreement that we’ve warmed since the end of the LIA.
Amazing.