If you've spent any time arguing with climate change deniers, you've probably discovered two things: #1) Your forehead hurts from banging your head against your desk, and #2) One of their go-to arguments is that the 97% consensus among climate scientists is not an accurate statistic. (By the way, when I say "global warming deniers," I don't necessarily mean just people who deny that the planet is warming, but also people who accept that it's warming but reject that human activity is responsible.)
Some deniers simply point out deficiencies in the consensus studies; others point to a survey which reaches a conclusion in the ballpark of 50%; and some go to the absurd length of arguing that the true statistic is actually only around 1% of the relevant scientists.
Here, we're gonna take a comprehensive look at the different studies and surveys used to reach conclusions about what percent of scientists believe that manmade global warming is occurring. I'm also going to break down the many flaws in the arguments and critiques used by deniers to poke holes in these studies, and to reject this data and support a much lower figure—on occasion agreeing that they do have valid critiques. (Yes, as the saying goes, even a broken clock is right twice a day—although in this case, it's more like twice a month, or twice a quarter, if we're being generous.)
After taking everything into consideration, here are the basic conclusions that I reach at the end of my analysis: Only 0.27% of climate change publications reject anthropogenic global warming; 84% of scientists, across a variety of fields, accept manmade global warming, as do 84% of climate scientists, overall, and 93% of the climate scientists that are most actively involved in research. And the remaining percentages aren't uniformly climate change deniers, but actually encompass a broad spectrum of belief. Finally, 85% of scientists believe that global warming is dangerous.
So while yes, technically the true statistic is lower than 97%, the data makes absolutely clear that the overwhelming majority of scientists accept manmade global warming. Much more important than the conclusion I reach is how I went about reaching this conclusion, and on that note, let's get started.
Ian Tuttle, in an article for The National Review, writes that
"The myth of an almost-unanimous climate-change consensus is pervasive. Last May, the White House tweeted: 'Ninety-seven percent of scientists agree: #climate change is real, man-made and dangerous.' A few days later, Secretary of State John Kerry announced, 'Ninety-seven percent of the world’s scientists tell us this is urgent.'
'Ninety-seven percent of the world’s scientists' say no such thing."
So where does this 97% statistic come from, and why do climate change deniers reject it? One of the main sources of this number is a 2013 study by John Cook et al.
Here's how this study worked: They searched the literature and found 12,000 scientific papers on climate change. Based on what was written in the abstracts, the papers were classified as either endorsing anthropogenic global warming, rejecting it, or not expressing a position. 67% expressed no position; of those that did express a position, 97% accepted, and 2% rejected, anthropogenic global warming.
Let me start out by agreeing with my climate change–denying friends—all zero of them: From this study, we can't reach a firm conclusion on the beliefs of climate scientists, because this wasn't an opinion survey. So when people cite this study as proof of what it is that climate scientists believe, as proof that they think climate change is dangerous, they are going too far. Now of course, many climate scientists do believe exactly that; I'm simply saying this particular study doesn't demonstrate that.
Here's the thing, though: Nowhere in the paper itself do they claim that their findings are exact reflections of the climate science opinions on these questions; they're very careful to state that their paper is only informative on the precise questions that they sought out to answer. As they write in the concluding section,
"The number of papers rejecting AGW is a miniscule proportion of the published research . . . Among papers expressing a position on AGW, an overwhelming percentage . . . endorses the scientific consensus on AGW."
Obviously the fact that it's not an opinion survey doesn't mean that it's completely worthless; this study is very informative on the question of what conclusions are being reached and taken for granted within the climate science community, and how prevalent these conclusions are.
Climate change deniers critique the methodology of this study in a way that makes clear that they don't actually understand the methodology of this study.
One critique is that the volunteers who did the abstract classifications were collected from the Skeptical Science website, which takes a staunchly pro–anthropogenic global warming position. (And of course, I don't mean pro–global warming as if they're cheering this on; they're like "Yes! Keep those greenhouse gases flowin', baby!" They travel to the North Pole just so they can flip off polar bears and be like "Just drown already!" No, I mean these volunteers were on the pro–global warming side in the sense that they believe that it's occurring.)
So yes, deniers are correct about where the volunteers came from and they're also correct in arguing that this could have biased the rankings. This would be a valid criticism if not for the fact that a core component of the study completely nullifies it.
As Cook et al write in the paper,
"In a second phase of this study, we invited authors to rate their own papers. . . . 2142 papers received self-ratings from 1189 authors."
Table 4 from the study shows us the data on how these authors rated their own papers, and as we can see, among papers that took a position, 97% of the self-raters described their papers as endorsing anthropogenic global warming. This is exactly the same as the 97% statistic that was arrived at by the volunteers.
Anthony Watts writes the following on the climate change denialism website WattsUpWithThat.com:
"Most people who read the headlines touted by the unquestioning press had no idea that this was a collection of Skeptical Science raters opinions rather than the authors assessment of their own work."
It's actually both, as they make absolutely clear in the paper. I love that this guy's like "Oh, the media isn't accurately describing the contents of this paper"—in the exact same sentence that he also isn't accurately describing the contents of this paper. That is richer than Al Gore plans to get off carbon taxes! If these deniers had actually read and understood the paper, they would know better than to level this completely toothless critique.
Deniers also point out that some scientists whose papers were classified disagree with the classification reached by the volunteers. Another article on WattsUpWithThat is entitled "Cook's 97% consensus study falsely classifies scientists' papers according to the scientists that published them," and then they go on in the article to cherrypick a measly 4 scientists who say that their papers were misclassified. From this, they conclude the following:
"The Cook et al. (2013) study is obviously littered with falsely classified papers making its conclusions baseless."
Really, dude? It's "littered" with falsely classified papers? This is the overstatement of the century. You found four people to attest to this—out of the 29,000 authors whose papers were analyzed in the study. 4 out of 29,000! That's like being in a football stadium filled with people, being told that a single person in the arena is a rapist, and saying "My goodness, this place is littered with rapists." Sorry, but the only thing that football stadium is littered with are nacho containers that Chris Christie dropped onto the ground so he could get into a fist-fight.
And again, this critique completely fails to take into consideration that 1,189 authors rated their own papers in the study and found almost perfect agreement with the rankings of the volunteers. Yes, there's a tiny percentage of papers where I'm sure there was disagreement, but to laser-focus on this is to miss the forest for the trees. It's very nice to shine a spotlight on four authors' individual grievances and to treat them as if they're representative of all of the authors, but if you actually look at what these authors collectively tell us, you find that the climate change–denier critique doesn't even make a dent, and it just doesn't match up with the facts.
Some deniers cleverly try to invert the findings of the study and argue that it actually proves the exact opposite of what it claims to. We hear this argument made in a PragerU video featuring Alex Epstein, author of the timeless classic The Moral Case For Fossil Fuels. (By the way, with Christmas right around the corner, I think we've found the perfect gift for the shameless oil lobbyist in your family!):
"One of the main studies justifying 97% was done by John Cook, a climate communications fellow for the Global Change Institute in Australia. Here's his own summary of his survey: 'Cook et al found that over 97% of papers surveyed endorsed the view that the earth is warming up and human emissions of greenhouse gases are the main cause.'
Main cause means over 50%. But the vast majority of papers don't say that human beings are the main cause of recent warming. In fact, one analysis showed that less than 2% of papers actually said that."
In support of this claim, Epstein references a Library of Economics and Liberty publication by David Henderson entitled "1.6%, not 97, Agree That Humans Are The Main Cause of Global Warming." Ah, yes, because when I'm looking for sound information on climate research, I consult the Library of Economics and Liberty, just as I get my information on astronomy from The Scuba Diver Quarterly.
Henderson looks at the number of papers in that Cook et al study that explicitly quantify human activity as causing more than 50% of global warming, and he finds that only 64 papers meet this criteria out of the 3,974 that expressed a view. As he concludes,
"The 64 who think the main cause is humans is, drum roll please: 1.6%. 1.6% is pretty different from 97%"
Now here, Henderson actually goes too far and needs to be reeled back in. This isn’t the percentage who think the main cause is humans; this is the percentage that explicitly stated and quantified in their abstract that the main cause is humans. Again, this wasn’t an opinion survey, so Henderson is wrong to frame these results as elucidating the beliefs of these climate researchers.
But let's ask the question: Is it wrong of Cook et al to describe this 97% as the percentage of papers which endorse anthropogenic global warming? I think a solid case can be made that they do actually overstate things—although I will talk later about how I think the climate change denier framing on this issue is all wrong.
In the paper, Cook et al describe "the scientific consensus" as the idea that "human activity is very likely causing most of the current GW." Thus, when they say "endorsement" or "rejection" in the paper, they mean endorsement or rejection of this specific idea. In the Cook et al study, there were three categories of endorsement: "Explicit endorsement with quantification"; "Explicit endorsement without quantification"; and "Implicit endorsement."
I invite you to ask yourself: Is it fair to describe a paper as endorsing the view that most warming is caused by human emissions if the paper doesn't explicitly state and quantify this? Perhaps we can infer that this is what they're saying even if they don't say it outright, or perhaps we can only confidently say this if they come right out and say that "most" or "over 50%" of the warming is caused by human activity.
I see where both sides are coming from here, but for the sake of analysis, let's just concede that, yes, they're overstating things, and the most we can say is that 97% of these papers endorse the idea that some warming is caused by human activity—not most of it. Still, the point remains: 97% of papers that took a position accept the reality of at least some manmade global warming. I don't see how this finding does any favors for the climate change denier, and when they force us to make this minor modification, what they're ultimately doing is snatching defeat from the jaws of defeat.
Now you might be saying at this point: "Hang on a sec, douche: The 97% statistic is misleading because most people who present that statistic don't provide the caveat that it's 97% of the papers that took a position! If you include the papers that took no position, it's actually only 33% that endorse manmade climate change." Ok, fair point: It's only 33% of all papers—and the percentage of all papers that reject manmade climate change is 0.65%. To look at these numbers in another way, the ratio of papers that accept and reject anthropogenic global warming is 50:1. So we can present this data any way you like—and you still lose.
One last point about this Cook et al study before we move on. In an article on WattsUpWithThat.com, Anthony Watts writes that:
"The new paper by the leading climatologist Dr David Legates and his colleagues . . . reveals that Cook had not considered whether scientists and their published papers had said climate change was 'dangerous.'"
No, this paper didn't "reveal" anything of the sort, actually, because nowhere in the original paper do Cook et al claim that their data is informative on the question of the danger of climate change. "Our crack team of researchers have discovered that your data doesn't support what you didn't say your data supports." Yeah, I think that's kind of how that works!
In my opinion, the most remarkable aspect of the Cook et al study is the miniscule percentage of papers that reject anthropogenic climate change—either explicitly or implicitly. According to their results, only 78 out of 12,000 papers reject manmade global warming.
This finding is similar to the other paper-abstract analyses that have been conducted. One of these was published by Naomi Oreskes in 2004. She investigated the subject in her study
". . . by analyzing 928 abstracts, published in refereed scientific journals between 1993 and 2003, and listed in the ISI database with the keywords 'climate change.'
. . . Of all the papers, 75% . . . either explicitly or implicitly [accepted] the consensus view; 25% dealt with methods or paleoclimate, taking no position on current anthropogenic climate change. Remarkably, none of the papers disagreed with the consensus position."
Another similar study was published by James Lawrence Powell in 2012. As he writes on DeSmogBlog.com,
"I searched the Web of Science for peer-reviewed scientific articles published between 1 January 1991 and 9 November 2012 that have the keyword phrases 'global warming' or 'global climate change.' The search produced 13,950 articles.
. . . To be classified as rejecting, an article had to clearly and explicitly state that the theory of global warming is false or, as happened in a few cases, that some other process better explains the observed warming.
. . . By my definition, 24 of the 13,950 articles, 0.17% or 1 in 581, clearly reject global warming or endorse a cause other than CO2 emissions for observed warming."
When his findings are represented graphically, as we see here, it really shows you how pitifully tiny is the number of papers that reject global warming. The sliver on the pie chart is basically the thickness of a strand of hair. At its widest point, it's like four pixels across.
I don't know about you guys, but I'm ready to take a look at some actual opinion surveys which show us what it is that climate scientists believe about global warming. As titillating as it is to try to infer their views from paper abstracts, it's much more informative to just flat-out ask what their views are, so let's get to it.
I always enjoy looking at the data and evidence that my opponents think best makes their case, so let's look at the main survey that climate change deniers love to wave before our faces: A 2014 publication by Neil Stenhouse et al in the American Meteorological Society. Here is how Anthony Watts introduces the study on WattsUpWithThat:
"A recent real survey conducted of American Meteorological Society members has blown Cook’s propaganda paper right out of the water."
And at the top of the article is a picture with the 97% statistic crossed out, and replaced with a 52% consensus based upon this AMS survey.
Watts closes out the article with a hilarious joke:
"So, the inconvenient truth here is that about half of the [AMS doesn't] think humans are 'mostly' the cause of Anthropogenic Global Warming"
He's like *while poking your ribs with his elbow*: "Inconvenient Truth! Ehh, get it?"
Oh, you mean like that Al Gore documentary! Brilliant! I have never in my life heard that one before! I don't know why this guy spends his time writing about climate change when clearly he has a very promising future as a stand-up comedian! For my next video on global warming, I might even try to collaborate with him and get him to write me a joke or two. I'll be talking about the warming of the oceans and I'm like: "Talk about being in some hot water," and then everybody unsubscribes and I kill myself!
To see if Anthony Watts is accurately representing the findings of this survey, we need to take a closer look at it.
Here we see a table from the study where they present their core findings. As we can see, the data is broken up by area of expertise and publication focus.
If you look at all respondents to the survey, you find that 52% said "Yes, global warming is happening, and the cause is mostly human." Another 10% said the cause is equally human and natural. I would argue these percentages should be added together, because if you think half of the warming is caused by human activity, clearly you accept that we are significantly responsible for the warming trends. So really I think 62% is more accurate.
I would even take it one step further and look at the people who say there's insufficient evidence to say what the cause of global warming is. While these people may not feel comfortable quantifying the precise degree to which human activity and natural causes are responsible, the table shows that 11 of that 20% say that humans are responsible for some of the warming. This would bump that 62% up to 73%.
And I think it's perfectly reasonable to include these people in the final statistic. If I were to ask a person: "Do you think humans are responsible for the global warming that we see?", and they say: "Well, certainly some of it," it simply wouldn't make any sense to classify this person as a manmade global-warming denier.
This is part of the problem with the climate–change denier approach to this subject: They have these very strict definitions of what does and doesn't count as accepting manmade global warming, and according to them, only those who specifically quantify that human activity is responsible for over 50% of the warming can be described as accepting manmade climate change.
I think the framing that they put around this question is all wrong, and if you adopt their framing, it makes it look as if the scientific consensus is much lower than it actually is. If a person believes that human activity is responsible for exactly 50% of the warming, or even that we're only responsible for 20 to 30% of the warming, they still ultimately believe that human emissions are at least partly causing global warming. Plain and simple, these people are on our side of the debate—not yours.
And even being responsible for a seemingly small amount like 20% of the warming could still have enormous consequences, because that right there could be the extra push that accelerates the positive feedback cycles and causes global warming to really take off, or it could be just enough warming that happens rapidly enough that it could cause that many more organisms to go extinct.
So you need to be mindful of how conversations are being framed, because if you just take these assumptions for granted, you could be wrongly conceding huge points without even being aware of it.
Let's take a closer look at the AMS members whose area of expertise is "climate science." Of these whose publication focus is "mostly on climate," 78% say global warming is happening and the cause is mostly human. Compare this against non-publishers, 38% of whom say global warming is mostly manmade. You are over 2x more likely to believe that global warming is mostly manmade if you're actively involved in publishing in this field.
Adding the 10% who think humans and natural causes are equally responsible, you find that 88% of the highest-publishing climate scientists accept manmade global warming. And if you add the 5% in the "insufficient evidence" category who say humans are responsible for some of the warming, you arrive at a final statistic of 93% of experts.
Another thing to note is that only 1% of climate science experts who mostly publish in that field say that global warming is not happening, and only 1% say that they don't know if it's happening. By comparison, 8% of non-publishers answered in these ways for both questions. That is to say, if you're not actually involved in publishing research in the field, you are 8x more likely to either reject, or claim you don't know, that global warming is happening.
We see similar trends in those whose area of expertise is meteorology and atmospheric science: Of those whose publication focus is mostly climate, 61% say, yes, global warming is happening, and the cause is mostly humans, compared against only 35% of non-publishers. 11% of mostly-climate publishers say they don't know if global warming is happening compared to 10% of non-publishers, and 2% of publishers say it's not happening compared to 7% of non-publishers.
So in these particular fields, if you're not involved in publishing research, you're almost 2x less likely to say that humans are mostly responsible for the warming, and over 3x more likely to say that global warming is not occurring. Notice also that, across all three fields, non-publishers are 2–4x more likely than publishers to say there's insufficient evidence to reach a conclusion about the cause of global warming.
These findings make absolutely clear that the more you're actually performing research and contributing to the field, the more likely you are to believe that global warming is occurring and that humans are mostly responsible. And it's almost a certainty that if you're publishing more research, you're also reading more research, because the two go hand-in-hand, as anybody who's ever looked at the references section of a paper can tell you.
The scientists who are more involved in research and publication are going to be more knowledgeable about recent developments in the field, so obviously we should find their opinions more trustworthy. And when being better informed about the subject directly correlates with a belief in manmade global warming, that is a very strong indicator that the belief itself is accurate. It would be a very strange world where being more scientifically informed makes you more likely to be wrong about the very scientific question that you're informed about.
And I don't even know what a non-publishing meteorologist would be doing for their career. I guess he could be your weatherman, where his job requirements are basically to look good on camera, check the Doppler Radar, and make the wrong predictions. Or maybe it's a person with a meteorology degree who now teaches high school science—or as I like to call them, hopeless alcoholics. I looked through the AMS membership criteria on their website, and I don't see anything there stopping a guy from becoming a member if he has a meteorology degree, yet all he does is work at a Starbucks or deliver pizzas.
I'm sure there are plenty of non-publishing scientists with educational backgrounds in these fields that do regularly consult the scientific literature as a part of their job, but obviously far fewer of them will than the scientists who actively publish in these fields.
Self-proclaimed climate change "skeptics" love to cite the figure of 52%, because it gives the impression of an equal balance, where there's a 50/50 debate within the scientific community, but the reality of the situation is very different from the denier's presentation.
As we've seen, these survey numbers are heavily dragged down by non-publishers in the field. If you look at the experts who do the most research in these fields, you find that the numbers starkly contradict the denier's presentation, where it's framed it as if the experts in this field are sharply divided on this question. From this AMS polling data, we can say that, yes, there is some controversy and debate within the scientific community—but the level of disagreement declines the higher one's level of involvement in the field.
Looking at the data also reveals that any viewpoint other than the one which says that humans are mostly responsible for global warming is in the extreme minority within the climate science community.
And the way these findings are presented by climate change deniers is misleading. When you hear that only 52% believe in manmade climate change, you might automatically assume that this means 48% do not believe in manmade climate change. Look at the pie chart they present us with on WattsUpWithThat.com: it's completely binary, suggesting a sharp dichotomy between two extreme positions.
If you actually look at the data, however, you find that this 48% is made up of scientists with a broad diversity of viewpoints: some say we simply don't know, others say natural causes are mostly responsible, other say it's an equal blend of human activity and natural causes, and so forth. So a more accurate pie-chart would look like this: One color on the one side showing the 52%, and a bunch of much smaller slivers which are colored differently showing the many other viewpoints that are held.
So even if we were to use the 52% statistic despite the already-mentioned problems with citing this number, it wouldn't be a 50/50 split between endorsers and deniers of manmade global warming; it's more like a 50 / 10/5/20/1/7/4 split between AMS members, on the one hand, who believe that human emissions are responsible for over half of the warming, and on the other hand, those who hold every other possible viewpoint along a wide spectrum that ranges from "humans are half responsible," "slightly responsible," "it's unknown how much we're responsible," and "warming is not occurring."
So if you're a denier of any variation and you point to this study as supporting your viewpoint, what you're really doing is pointing to research which shows that your viewpoint is soundly rejected by a ratio that ranges anywhere from 50:1 to 2.5:1, depending upon what your exact belief is—and this is using the most generous interpretation of these numbers in your favor, where the non-publishers who substantially drag down the numbers are included, and where scientists who technically do accept manmade global warming aren't classified as such according to the red lines that you've drawn in the sand for us.
According to the most inaccurately generous interpretation of this data, whatever your position is has been shown to be in the extreme minority. You think you're patting yourself on the back here, but you're really shooting yourself in the foot.
And here is the icing on the cake: the official position of the American Meteorological Society on global warming—made explicit on their website—is as follows:
"It is clear from extensive scientific evidence that the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases"
So as we can see, the climate change–denier portrayal of this AMS survery is misleading and flawed for many different reasons. They say 52%, but realistically, if you don't use their restrictive criteria, it's more like 73%. And if you look specifically at the top-publishing climate scientists, you find that around 93% accept manmade global warming.
You might disagree with me expanding the classification criteria in this way—and if you're a climate change denier, there's a good chance you've already seized upon that and posted a comment expressing your outrage before you've even reached this point—but at least I'm telling you exactly how I'm arriving at these different numbers, and I'm not just presenting you with the one statistic, the one interpretation of this data, that best supports my case and saying: "That's the number—end of discussion."
52% versus 73% and 93%—or perhaps even higher if we further loosen the inclusion criteria. Those are sizeable differences right there, and this is why it's very important to be skeptical of what people tell you, not take their claims at face value, and carefully investigate the evidence for yourself. This is a great example of how easy it is to deceive people with statistics, and how wildly different conclusions can be reached from the exact same set of numbers.
As we will soon see, there are other surveys of climate scientists on these exact same questions that yield significantly higher results, yet the one survey that deniers choose to shine a spotlight on is the one that they can squeeze the lowest possible number out of. This is not the way that a person who cares about the truth operates.
Another survey of climate scientists was conducted by Bart Verheggen et al in a 2014 Environmental Science & Technology publication.
Here's how the study was conducted: About 6,000 author names were gathered from a literature search using the keywords "global warming" or "global climate change." Another 2,000 names were collected from a public database of relevant scientists. They were all e-mailed a questionnaire and their responses were tallied up and compared.
One question asked them how significant a contribution anthropogenic greenhouse gases have made to global warming since pre-industrial times. Their responses are broken down in Figure 1 by their number of publications. As we can see, by far, the most popular answer to this question was that manmade GHGs have strongly contributed to warming trends, with the percentage that selected this ranging from 55% to 75%.
Also noteworthy is that, once again, there is a direct correlation between the percentage which selected this response and how many papers in the field they've published: those with 0–3 publications averaged 55% who selected "strong contribution"; those with 4–10 publications averaged 63%; 11–30 publications, 68%; and 31–300 publications, 74%. You couldn't create a more perfect, stepwise progression in a laboratory!
The percentage who said that manmade GHGs have made a "moderate" contribution to warming was about 20–25%, depending on publication level. Let's add these two categories together—strong and moderate contribution—and break down the answers by publication level: 0–3 publications, 26 + 55 = 81%; 4–10 publications, 26 + 62 = 88%; 11–30 publications, 22 + 68 = 90%; and 30–300 publications, 18 + 74 = 92%.
If you average these four percentages, you arrive at an overall statistic of 88% who believe than human GHG emissions have made either a strong or moderate contribute to warming levels. This number would have been even higher if not for the fact that some percentage of the respondents had their brains so overheated by global warming that they just couldn't think straight!
Another interesting trend is revealed in Figure 4. Here, they categorized the respondents into two key groups: one which said that manmade GHGs were responsible for less than 50% of the warming, and another which said that they were responsible for more than 50% of the warming.
The key observation here is that those who said manmade GHGs caused less than half of the warming were much less confident in their answers, with only 15% describing their conclusion as "virtually certain" and about 7% saying it's "extremely likely." By comparison, when you look at those in the more-than-half group, you find that they classified their conclusion as either "virtually certain" or "extremely likely" about 35% of the time in both cases.
Adding both answers together and comparing the two groups shows that 22% in the less-than-half group were very confident in their answer compared to 70% in the more-than-half group. That is to say, those who believe that human emissions cause over half of the warming are 3x more confident in their views.
So once again, we find that about 90% of the top-publishing climate scientists believe that human activity plays a significant role in climate change. And the thing is, this statistic is likely to be an underestimate as a result of the research methodology, because, as they write,
"Prall’s database also includes signatories of public statements disapproving of mainstream climate science. They were included in our survey to ascertain that the main criticisms of climate science would be captured.
. . . By also soliciting responses from signatories of public statements who are not necessarily publishing scientists, it is likely that viewpoints that run counter to the prevailing consensus are somewhat magnified in our results. This is further exacerbated by this group exhibiting a relatively higher response rate"
So basically, they went out of their way to include more climate change deniers in the survey—and on top of that, this group of additional climate change deniers was more likely to answer the questionnaire than the rest of the respondents. Even with these two separate sources of bias in favor of climate change denialism, they found an overall 88% consensus on manmade global warming.
One final thing from their paper is worth noting:
"Those who estimated the qualitative greenhouse contribution . . . to be insignificant or negative (i.e., cooling) reported significantly more frequent . . . media exposure than those who estimate GHGs to have exerted either slight, moderate or strong warming. . . . those who most strongly disagree with a discernible influence of anthropogenic GHGs on climate are overrepresented in the media, relative to the prevalence of these opinions in the scientific community."
So despite the fact that climate change deniers will cry and complain about being ignored in the mainstream media—oftentimes conjuring up some kind of vast, dark conspiracy to explain this—the fact of the matter is that they are actually significantly overrepresented.
Another survey was conducted by J.S. Carlton et al in 2015. The research methodology and their findings are described in the paper as follows:
"Here, we report on a survey of biophysical scientists at universities in the Big 10 Conference, a group of large, research-oriented universities in the United States . . . Within each college, departments were identified that fell under the categories of biology, chemistry, physical sciences, environmental sciences, or geosciences. . . . To create the sample, 2000 names were randomly selected from the list of scientists.
The results suggest a broad consensus that climate change is occurring: when asked 'When compared with pre-1800's levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?', 93.6% of respondents across all disciplines indicated that they thought temperatures have risen, 2.1% thought temperatures had remained relatively constant, 0.6% thought temperatures had fallen, and 3.7% indicated they had no opinion or did not know.
. . . Of those who indicated that they believed temperatures have risen, 98.2% indicated they believe that 'human activity is a significant contributing factor in changing mean global temperatures'."
98.2% of the 93.6% who said that temperatures have risen yields a statistic of 92% of scientists—coming from a wide range of disciplines—who believe both that global warming is occurring and that human activity significantly contributes to this warming.
Another survey was conducted by Peter T. Doran and Maggie Kendall Zimmerman in 2009. They sent out a questionnaire to about 3,000 Earth scientists compiled from a database. I always thought that was a funny phrase, by the way: "Earth scientist." Isn't every scientist technically an Earth scientist?
(As I say that, a Martian teleports into my room and he's like: "As a matter of fact, they're not!" And I'm like "Oh, uh...thanks for clearing that up!...Sooo, like, what now? Is that it, or, was there anything else you wanted to talk about?", And he's like "Well, I mean, since I'm already here, I was thinking maybe we could just hang out for a bit?", and I'm like "You know what, man? I'd really love to, but I'm super swamped right now; now is not a good time." He's like "Oh, yeah, fine. I see how it is. I bend over backwards, teleport into your apartment, but you're too busy for me! I get it. I'm used to it by now." And I'm like "Hey, come on, don't cry." ...I don't really know how to end this joke, so we're just gonna leave it there!)
What was I talking about again? Oh yeah: anal probing. No, I mean Doran & Zimmerman 2009. So like I said, they surveyed 3,000 Earth scientists, asking them two questions:
"1. When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant? 2. Do you think human activity is a significant contributing factor in changing mean global temperatures?
. . . Results show that overall, 90% of participants answered 'risen' to question 1 and 82% answered yes to question 2. In general, as the level of active research and specialization in climate science increases, so does agreement with the two primary questions."
And here we see this trend clearly depicted in this graph from the study. Also notice the massive disconnect between the general public and the scientific community on these questions. Only about 55% of the general public believes in manmade global warming. What an abject embarrassment!
90% of scientists answered "risen" to question 1, and 82% answered "yes" to question 2. 82% of 90% = 74% of scientists, generally, who believe in anthropogenic global warming.
Why the discrepancy, you might be asking yourself? The last survey of scientists across many disciplines found that 92% agree with basically the exact same statements. Well notice the dates of these studies: This current one was published in 2009, whereas the previous one was published in 2015, so it could simply be the case that scientific opinion has changed on this subject over that period of 6 years. I guess all of those climate change deniers in the media just haven't been making a very convincing case!
Dorran and Zimmerman go on to write the following:
"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% . . . answered 'risen' to question 1 and 97.4% . . . answered yes to question 2."
97.4% of 96.2% = 94% of climate science experts who believe that temperatures are increasing and that human activity is significantly responsible.
Joseph Bast and Taylor Smith attempt to critique this paper in a 2014 Heartland Institute publication. As they write,
"This study, too, has been debunked. The survey asked the wrong questions. Most scientists who are skeptical of catastrophic global warming also support those statements."
Uh, ok? And how does pointing that out "debunk" the study? "We agree with the statements presented in your survey!"—that is not a refutation of the survey.
"The survey was silent on whether or not the human impact was large enough to constitute a problem or would cause a problem in the future."
Yeah, it was silent on those questions because they didn't set out to investigate those questions in the study. This is what their critique boils down to: "Your survey didn't ask a question that it didn't ask." *sarcastic, rapid applause* Fucking brilliant analysis! My goodness, somebody give these two a Nobel Prize or something! This is a complete non-criticism right here.
They're just moving the goalposts when they say "Well, you didn't answer this question about whether global warming would constitute a problem!" Yeah, they didn't answer that question because they didn't ask that question. The impact of climate change is separate from the cause of climate change, and it is the latter that they sought to investigate.
And it's not really for climate scientists by themselves to determine whether global warming will be a major problem; the study of climate is separate from the impact of climate, and determining the impact is an interdisciplinary endeavor that involves biologists, oceanographers, pathologists, and so forth.
But yes, let's ask the question: What percentage of scientists do believe that climate change is dangerous? A 2007 STATS survey was conducted on about 500 scientists who were either members of the American Meteorological Society or the American Geophysical Union.
"Based on current trends, 41% of scientists believe global climate change will pose a very great danger to the earth in the next 50 to 100 years, compared to 13% who see relatively little danger. Another 44% rate climate change as moderately dangerous."
So 85% of scientists think that climate change is dangerous—with about a 50/50 split between those who think it's extremely dangerous and those who think it's moderately dangerous. And this is survey data from a decade ago; current statistics on these questions are likely to be even higher.
Considering that this data was published 7 years before Bast & Smith wrote on the subject, why did they not reference these findings? They complain in their paper that certain studies didn't investigate scientist opinions on the dangers of climate change, yes here is a survey which does exactly that—and it finds that the vast majority think climate change is, in fact, dangerous.
What a curious oversight on their part to not mention this! I'm sure it just...slipped their mind or something! Or maybe they were just so busy complaining about the lack of data on the danger of climate change that they couldn't find the time to look for data on the danger of climate change? It took me a single Google Search and two clicks to find this survey, so I would like to know what is their excuse for not mentioning this data.
Bast & Smith go on to write:
"Moreover, the '97 percent' figure represents the views of only 79 of the 3,146 respondents who listed climate science as an area of expertise and said they published more than 50 percent of their recent peer-reviewed papers on climate change. This is not evidence of consensus."
Gentlemen, I have news for you: There's this little thing in science called sampling where you don't actually have to take measurements of every member of a group to be able to accurately describe the characteristics of that group. Yes, 79 is not a big sample size, but it's not nothing—and the findings of this study are very similar to those of the other studies which had larger sample sizes.
Pew Research, in 2014, surveyed about 3700 members of the American Association for the Advancement of Science—1600 of whom had PhDs and 1200 of whom were active research scientists.
They found that, across all fields, 87% of respondents believe that climate change is mostly caused by human activity. Among working PhD scientists, it was 88%, and among active research scientists, 90% said that climate change is mostly due to human activity.
"Pfft, active research scientists? Yeah right. They probably just spend their days researching how to get bigger checks from George Soros!"
We're gonna look at one last survey, published by Steve Milloy in 2007 on CanadaFreePress.com. As he writes,
"I e-mailed a six-question survey on climate change to 345 U.S. scientists involved in the IPCC’s 2007 report. . . . In the end, 54 of the IPCC-ers completed the survey.
. . . The responses to the survey’s first four questions were predictable— 83% to 90% of the respondents favored the view that manmade carbon dioxide (CO2) emissions are driving global climate to unprecedentedly warmer temperatures and that limiting manmade CO2 emissions would reduce such climate change."
83 to 90%. We'll just take the average here and go with 87%. Notice that this is also a poorly framed question: "manmade CO2 emissions are driving global climate to unprecedentedly warmer temperatures"? My understanding is that there have been periods of time where temperatures on the earth were substantially higher than they are today, so even if you accept that manmade climate change is happening right now, the grammar of the question might nonetheless lead you to answer "no." If the question was worded appropriately, the survey results undoubtedly would have been higher.
He also has another question in the survey where the framing is all wrong:
"Other notable results include the 20% who bizarrely said that human activity is the principal driver of climate change. So was climate a static phenomenon before the arrival of man? And if there was natural climate change before man, why not now also?"
He thinks he's making a "gotcha!" point here, but all he's really doing is showcasing that he asked a poorly-worded question. 20% said human activity is the principal driver of climate change? That's probably because this 20% interpreted this question as asking if we're the principal driver of current, ongoing climate change—not climate change generally throughout all of earth's history.
Yes, nobody thinks humans went back in time and warmed up the planet 200 million years ago. This is such a painfully obvious fact that when you asked your shitty question, they probably generously thought: "Nobody would be stupid enough to suggest that human emissions are responsible for climate change that took place before humans even existed."
Nobody has ever argued that humans are the only conceivable cause of any climate change that has ever happened, so you're not making any clever points here and you're actually just embarrassing yourself.
"44% percent don’t think that current global climate is unprecedentedly warm."
Yeah, and? The sole problem with climate change isn't the temperature levels themselves; a big part of the problem is how rapidly temperature levels are increasing. If temperatures rose 10 degrees over a period of 500,000 years, life would have plenty of time to adapt to these gradual changes without facing widespread extinction. But if we're talking about 10 degrees in a matter of mere centuries, these are very rapid environmental changes that many lifeforms will simply not be able to adapt to in time. So it's not just the temperature levels that are the problem; it's the pace of change that is such a threat to life on earth.
Let's use a videogame analogy here: Imagine that it's another sad night of not getting laid, and you're sitting at home playing Halo 5. If you're anything like me, you're probably a crippling videogame addict who's been playing for like seven hours straight and is slowly starting to hate himself inside for being so unproductive.
You finish up a game and, after telling you that he fucked your mom last night, a person says: "Look, this guy on your team, throughout the entire game, got shot way more times than you did, yet he didn't die a single time!" Yeah, he may have taken more damage overall, but this damage was spaced out over a long time period, and he allowed his shields to recharge each time and that's why he never got killed. Even if, over the span of an entire game, you take less damage than he does, if the damage is concentrated within very short time periods, you're not gonna have time to recharge your shields and you're gonna get killed.
Steve Milloy finishes strong in his paper by minimizing the importance of consensus in science.
"The whole idea of a consensus in science is dubious. . . . economist John Kay recently wrote . . . an op-ed entitled 'Science is the pursuit of truth, not consensus'"
Right, and if the survey results found that 90% of climate scientists rejected manmade global warming, I'm sure you'd be saying the exact same thing about how consensus is no big deal and we shouldn't really think too much about it.
Milloy also brings up the fact that many scientists reject manmade global warming:
"There’s also the Petition Project, where 19,000 scientists have endorsed a statement questioning the scientific basis of climate alarmism."
"There are about 21.1 million people who have a bachelor’s or higher degree in a science or engineering (S&E) field"
31,500 out of 21.1 million is 0.15% of scientists in the United States who have signed this petition. To put this in perspective, there were about 1,000 people that attended my high school. 0.15% of 1,000 people, rounding up, is two people. Or, if you wanna get technical, we could say it's one person, then another person chopped in half. He's like: "Why would you chop me in half just to make a shitty analogy about climate change?! Everybody understands rounding up, you idiot!" And then he bleeds out to death, and I go to prison for life, and I'm sitting in my prison cell like: "Fuck. That was a stupid idea."
If there were only two people in the entire high school who signed a certain petition, would it make any sense to frame this idea as one that's widely held within the school? Of course not. Statistically speaking, in 2018, you'd probably have more mass shooters in your high school!
And it gets even better than this: The Petition Project isn't a collection of signatures exclusively from climate experts. Only 39 of them are experts in climatology. That's a whopping 0.12% of signees. 112 are experts in atmospheric science, and 343 are experts in meteorology, bringing us to a grand total of 494 signees, or 1.6% of them, whose credentials are directly relevant to climate change.
The rest of them have educational backgrounds in a wide variety of disciplines, ranging from geology to biochemistry to mechanical engineering. Sure, they could only manage to find 39 climatologists to sign their petition, but at least they were able to find 149 zoologists to sign. 163 experts in foresty signed your petition? Great—and if I need any help clearing some brush or scaring some bears away, I'll call them. Just look at some of the irrelevant qualifications that they flaunt before us. Mathematics? Entomology, the study of insects? Computer science?
Gimme a fucking break dude: The Petition Project is a joke. And I have to say, 242 experts in computer science signed your petition, and not one of them offered to redesign your website? Your website looks like it was created in 1997. The textured background is a really nice touch. And the scrolling list of names on the side? That shit is straight out of the future!
31,500 scientists might sound like a lot of scientists, but only a tiny fraction of them even have an educational background that's relevant to climate change. And there is a good reason why this data is being presented to us as the lump total of signees: because if they tried to show us the actual percentage of scientists who agree with them, the result would be nothing short of embarrassment. Nobody's going to start a website or organization that brags about the fact that only a tiny percentage of scientists reject manmade global warming, so all they can do is create the misimpression of widespread agreement with their views by showing us the total number—and not the percentage—who agree with them.
It's especially unconvincing when all you do is show us a single expert who agrees with your position. Here's a good example of this: Look at this PragerU video featuring a climate change–denying scientist.
"I'm an atmospheric physicist. I've published more than 200 scientific papers. For 30 years, I taught at MIT . . ."
Wooow, PragerU: You managed to find a single publishing scientist who agrees with you? Consider me convinced! Everybody knows that a person with a British accent who taught at MIT can't be wrong about anything.
I can find you doctors who support homeopathy and biologists who reject evolution. The fact that these oddballs have an expertise in this field doesn't necessarily make them correct—and when they're vastly outnumbered by colleagues that disagree with them, we should view their opinions with a great deal of skepticism.
The Petition Project is also cited by Joseph Bast and Taylor Smith in their Heartland Institute publication, and this I find especially amusing, because you'll recall that earlier, they were the ones complaining about supporting evidence not being based upon a large enough number of climate scientists! The 79 climate science experts in the Doran and Zimmerman study just weren't good enough for them—but apparently, the 39 climatologists who signed the Petition Project are good enough.
So when it comes to opposing evidence, they have very exacting standards indeed; yet when it comes to supporting evidence, all bets are off they're more than happy to flaunt in front of us the signatures of a bunch of mostly non-climate scientists as if that proves anything. This is naked hypocrisy right here.
So after taking a close look at all of these different studies and surveys, what can we say about the percentage of scientists who believe in manmade global warming?
First, there were the three studies which looked at the abstracts of climate change publications. Although these types of studies don't accurately measure opinion itself, they are informative on the question of how commonly manmade global warming is accepted or rejected, either explicitly or implicitly, in the scientific literature. These studies found that, of the papers which expressed a position, the vast majority accepted at least some manmade global warming,
Much more remarkable, however, is the fact that only the tiniest portion of the papers rejected manmade global warming: 78 out of 12,000 according to Cook et al 2013; 0 out of 928, according to Oreskes 2004, and 24 out of 14,000, according to Powell 2012. As a percentage, these are 0.65%, 0%, and 0.17% of climate change publications that reject manmade global warming—or 0.27% of publications, on average.
What about the actual opinion surveys?
Here is the data on the percentage of scientists, generally, that believe in manmade global warming: 74%, according to Doran & Zimmerman 2009; Pew Research 2014, 87%; Carlton 2015, 92%, yielding a final, average statistic of 84% of scientists, across a wide range of disciplines, that believe anthropogenic climate change is occurring.
What about climate scientists, specifically? First we'll look at the overall numbers, then we'll look at the numbers for the climate scientists that are most actively involved in research in the field.
For the overall numbers, the data is as follows: Stenhouse et al 2014, 73%; Verheggen et al 2014, 88%; Doran & Zimmerman 2009, 88%; and Milloy 2007, 87%. The average of these four findings is 84% of climate scientists who believe in manmade climate change.
However, if you look at the beliefs of the climate scientists who are the most prolific publishers of research in the field, that Stenhouse 73% becomes 93%, that Verheggen 88% becomes 92%, and that Doran & Zimmerman 88% becomes 94%, yielding an average of 93% of the most qualified, knowledgeable, and top-publishing climate scientists who accept manmade global warming.
Also recall that, in that Verheggen study, the results were biased in favor of climate change denialism. And in Milloy 2007, the questions were poorly worded in a way that would likely drag the numbers down. If you correct for these different sources of bias, the final statistics would be slightly higher.
So here are the core, takeaway statistics: Only 0.27% of climate change publications reject manmade global warming. 84% of scientists, across all fields, accept manmade global warming, as do 84% of climate scientists, overall, and 93% of the top-publishing climate scientists. Finally, 85% of scientists believe that global warming is dangerous.
And assuming that you don't have Alzheimer's, you'll also remember that belief in manmade global warming increases in direct proportion with one's level of expertise and amount of research contributed to the field. Basically, the more one knows about the subject, and the more involved one is within the field, the more likely they are to believe that human emissions are driving climate change.`
Yes, these numbers are less than the often-cited 97% statistic, but they're also substantially higher than the disingenuously-cited 52% statistic. There is no victory here for the climate-change denier: "Haha! Only still-the-vast-majority of climate scientists think I'm completely full of shit! Awesome! Take that, John Cook!"
Finally, don't make the mistake of concluding that because 84–93% accept manmade global warming, this therefore means that 7–16% reject manmade global warming; this dissenting 7–16% includes a wide spectrum of alternative beliefs: some do outright reject that global warming is occurring, but others say the cause is mostly natural—not manmade—and some simply say that we don't yet know what the exact cause of global warming is.
The data is absolutely clear on this question: the overwhelming majority of scientists and climate scientists believe that manmade climate change is occurring, and only a very small percentage reject this idea.