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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No, it “should” say “75 out of 157” … or “Only 47% of climate scientists believe CO2 is the cause of CAGW ..”
(157 is that 5% of the replies who claim to be climate scientists.)
Or, it “should” say “75 out of 267” or “Only 28% of climate scientists believe CO2 is the cause of CAGW ..”
(267 is that 8.5% who have written 50% or more of their papers in the past 5 years covering climate science research.)
Or, it “should” say “75 out of 3,146” or “Only 2.4% of climate scientists believe CO2 is the cause of CAGW ..”
(All of those who bothered to reply to the on-line survey.)
Or, it “should” say “75 out of 10,257” or “Only 0.7 % of climate scientists believe CO2 is the cause of CAGW ..”
(which includes all of the people who were asked to complete the survey.)
Daveburton
You claim this is a science blog, then quote the bible to me.
Well done – that was better Poe than the article itself!
Orion, Christian-bashing is not an answer to the question. When Doran & Zimmerman counted only half of the dissenters, do you think it was an unintentional blunder or intentional deception?
pappad says: “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?”
It’s because when CO2 molecules are floating in the air, the C is lighter than the O and the C side points toward the sky. So they are like little tiny arrows that only allow the IR go one direction.
Well that’s about as “sane” as anything coming out of the Greenie movement.
RACookPE1978 says:
….
Or, it “should” say “75 out of 3,146″ or “Only 2.4% of climate scientists believe CO2 is the cause
…
Hi All,
A very quick google search found the Wikipedia page which says of the 2009 survey:
“Among all respondents, 90% agreed that temperatures have risen compared to pre-1800 levels, and 82% agreed that humans significantly influence the global temperature.”
http://en.wikipedia.org/wiki/Surveys_of_scientists'_views_on_climate_change
You can also read this in the reference which is linked in Wikipedia.
The wikipedia site also has info about other surveys from 1990s to 2013.
Cheers
R.
Pippen Kool says:
December 12, 2013 at 10:36 am
It’s because when CO2 molecules are floating in the air, the C is lighter than the O and the C side points toward the sky.
Without adding “sarc”, we do not know if you mean it. But for the record, CO2 is linear, but H2O has an angle of 104.5 degrees between H and O.
pappad asked, “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?”
There are approximately equal amounts of radiant energy arriving at the Earth from the Sun, and departing from the earth into outer space. However, the spectra of the incoming and outgoing radiation are different. Because the Sun is much hotter than the Earth, the incoming radiation has more short wavelength light (UV and visible), and the outgoing radiation is predominantly longer wavelengths (IR).
It happens that CO2 absorbs in a couple of IR bands, but it is transparent to UV and visible light. Since there’s more outgoing radiation in those bands than incoming radiation, the CO2 blocks more outgoing radiation than incoming radiation.
However, it is important to note that additional CO2 has only a small effect on temperatures, because there’s already so much CO2 in the atmosphere that almost all of the UV in its absorption bands is already blocked. MODTRAN Tropical Atmosphere calculates that just 20 ppm of CO2 would have fully half the warming effect of the current 400 ppm. The NCAR Radiation Code says 40 ppm, but, either way, we’re way past the point of diminishing effects from additional CO2.
Adding CO2 to the atmosphere is like adding blue food coloring to a bowl of water. The first few drops have a dramatic effect on the water’s color, but after that adding additional food coloring has diminishing effects.
Still doesn’t answer the question. Are you trying to claim that the solar radiation coming IN has no IR…only the radiation going out? That “bouncing” off of the Earth’s surface “changes” it somehow? Greenhouses work the way they do because the glass (or plastic) traps the warmed AIR in an enclosure–but there ISN’T any “trap” in the atmosphere.
False.
I’m reading the data and quoting the words from the original research paper, NOT what has been re-written into Wikipedia by pro-CAGW propagandists.
What , do you mean like raw data ? But surely it needs to be corrected before it can be used to support the cause.
romena wrote, “…which says of the 2009 survey: ‘Among all respondents, 90% agreed that temperatures have risen compared to pre-1800 levels, and 82% agreed that humans significantly influence the global temperature.’”
However, they didn’t ask the 2nd question of everyone. Those who said “remained relatively constant” in reply to Q1 weren’t asked Q2. So “82%” is inflated, because they excluded some of the skeptics.
Quoting from the Zimmerman report (which I purchased):
The 5.7% who answered “remained relatively constant” were not asked the 2nd question:
So, actually, at most only 82% of 94.3% = 77.3% agreed with their watered-down “consensus.”
If some of those who answered “yes” to Q2 were among the (0.5% + 4.2%) who said “fallen” or “no opinion” to Q1, then the “consensus” was even less than 77.3%. They probably were, we can’t know for sure, because Zimmerman did not report that.
So they found a “consensus” among academic & government “earth scientists” of at most 77.3%… and that’s in spite of the fact that the questions were so weak that even a skeptic like me would have given the “right” answers, and so been counted as supporting their “consensus,”
BTW, if anyone has any questions about the Zimmerman report, THE CONSENSUS ON THE CONSENSUS: AN OPINION SURVEY OF EARTH SCIENTISTS ON GLOBAL CLIMATE CHANGE, just email me. My address is on my web site:
http://www.sealevel.info/
The Doran survey was the single most fraudulent piece of scientific trash that changed me into a global warming skeptic. That the AGU would publish this and the scientific community accepted all
the fraudulent claims associated with it ,convinced me it was a huge con job, no different than accepting the claims of used car salesman ( no offence to used car salesman, you are still more respectable than the science that promotes this garbage).
I don’t know if any one has noticed or mentioned this before . I absolutely believe the increase in global temperatures and CO2 caused by human activity is true. I spend a lot of research ( and money given to me to a well known brewery) oh forget it, you get the point.
It is caused by the heated rise in body temperature on the faces of the 97% and the added efforts they are spending to HA “deny” this and then using fossil fueled backhoes to dig holes to hide in eventually having to use the same machinery to dig themselves out of said holes when the next set of “undeniable” statistics become available.
pappad asked, “Are you trying to claim that the solar radiation coming IN has no IR…only the radiation going out? That “bouncing” off of the Earth’s surface “changes” it somehow?”
The incoming solar radiation doesn’t contain “no IR,” but it contains less IR than the radiation going out. When the Earth absorbs short-wavelength radiation, it is re-emitted as long-wavelength radiation.
The radiation absorbed by an object does not necessarily have the same spectrum as the radiation emitted by it.
Example #1: The food in your microwave oven absorbs 2.45 GHz microwave radiation (wavelength 12.4 cm), and then glows in the infrared (with a peak wavelength at less than 10 microns) as a result.
Example #2: A dark object warmed by the sun absorbs a broad spectrum of sunlight, including visible and UV, and gets warmer as a result. But it emits only IR. Thus it effectively converts incoming short-wavelength radiation into long-wavelength radiation going out.
However, you are correct that the term “greenhouse gas” is a misnomer, because greenhouses don’t work that way. Greenhouses work mainly by blocking convective heat loss, not radiative heat loss.
There is no consensus?
“We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’.
We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming.
In a second phase of this study, we invited authors to rate their own papers. Compared to abstract ratings, a smaller percentage of self-rated papers expressed no position on AGW (35.5%). Among self-rated papers expressing a position on AGW, 97.2% endorsed the consensus”
http://www.skepticalscience.com/docs/Cook_2013_consensus.pdf
http://theconsensusproject.com/
,..except that claiming a “consensus” is as UNscientific as anything I’ve ever heard of. There IS no such thing as “scientific consensus.” That’s a complete oxymoron. There once was a “consensus” that Pi was 3, that the world rode on the back of a gigantic turtle, that a lunar eclipse was caused by a giant wolf taking a bite out of it, that malaria was caused by an evil “miasma” emanating from swamps, that “bleeding” someone with a fever would cause the fever to go down, that people would die at any speed over 45 mph, that it was not possible to exceed the speed of sound in and airplane, that man would NEVER learn to fly, and that “government” could solve all our social problems with the stroke of a pen.
Ahh. Spectator is referring to the yet more ridiculous attempt at breathing life back into the ‘concensus’ by Cook et al. in his more recent yet seriously contrived attempt at reloading the 97% Myth.
The Doran & Zimmerman paper is a beacon of scientific integrity when compared to this latest attempt that demonstrates just how far and how fast academic standards have fallen in the meantime.