I have always been interested in the concept of consensus, even before that word became centered in the pro vs. anti science debate. In Anthropology, we have huge problems with consensus. In at least one branch of Anthropology, consensus can never be achieved because all good work is defined as breaking consensus. The moment you get close to consensus, you’ve failed. (That’s socio-cultural anthropology, modern style). In another branch of Anthropology, we deal with questions that can’t really be answered at that level, but sort of can be. So there is never consensus in the sense that of the many possible explanations for a thing, there will always be a list of possible, and often very distinctly different, alternative explanations. But, over time, the list changes. One hopes for the list we have now being better than the list we had a decade ago, even if both lists are approximately the same length. (Example: Reasons for the origin of bipedality in the human lineage.)
There is a particular kind of consensus that to my knowledge my friend John Cook does not talk about (yet, he’s got most of this covered very well): Beer pitcher consensus. It goes like this. Suppose there is a range of thought on a particular narrowly defined scientific question. Since this is about climate, let’s do a climate one. The question might be: What is the best value for “climate sensitivity.” This is the number of degrees Celsius that the atmosphere at the Earth’s surface will go up with a doubling of atmospheric CO2 from pre-industrial values (say that was about 280ppm). (I’m oversimplifying the concept and the question slightly and I believe forgivably.) The answers range from a somewhat pedantic and absurd 2.0 to an alarming and probably alarmist 5.6 or so.
Now, get a bunch of experts on this question, say at a conference. Sit them down for a beer. After a couple of beers, tell them, “OK, folks, I’m giving each of you a piece of paper and a pencil. Write down a guess on the climate sensitivity value. Here’s the thing. Don’t show each other what you wrote down, only show it to me. And, if they are all the same value, I’ll buy pitchers of beer for the rest of your time at this conference, starting now.”
Had I simply asked this group of experts to tell me the climate sensitivity value, it would start a conversation that would go on for hours, and there would not be a single number. But if I do it as described here, they would all write down one number, and it would be 3.5 (I’m pretty sure).
That is the beer pitcher consensus.
Anyway, have a look at John Cook’s excellent video. It shows why most of the time you as a science oriented concerned lay citizen usually get this wrong, but in a harmless way. There is not a “97%” consensus. There is a full consensus; the number 97% is kinds of silly, and it is only part of the picture. The idea that global warming is happening and is human caused is, simply put, established scientific fact. There is no valid dissent. But, the number “97%” does have an important meaning and history in the debate. More to the point, not only is there a consensus on climate change and the human cause of it, but there is a consensus on the fact that there is a consensus!
Last week, House Representative Lamar Smith held yet another masturbatory hearing to promote climate science denial. Smith is bought and paid for by Big Oil, so that is the most obvious reason he and his Republican colleagues would put on such a dog and pony show, complete with a chorus of three science deniers (Judith Curry, Roger Pielke Jr, and John Cristy). I don’t know why they invited actual and respected climate scientist Mike Mann, because all he did was ruin everything by stating facts, dispelling alt-facts, and making well timed Princess Bride references.
The hearings were called “Full Committee Hearing- Climate Science: Assumptions, Policy Implications, and the Scientific Method.”
Several others, including specialized climate science writers as well as mainstream media, have written about the hearings:
<li><strong>Dana Nuccitelli at the Guardian:</strong> <a href="https://www.theguardian.com/environment/climate-consensus-97-per-cent/2017/apr/04/inconceivable-the-latest-theatrical-house-science-committee-hearing">Inconceivable! The latest theatrical House 'Science' committee hearing</a></li>
… as is usually the case in these hearings, despite being presented with the opportunity to learn from climate experts, most of the committee members seemed more interested in expressing their beliefs, however uninformed they might be.
At the 2:04:05 mark in the hearing video, Rep. Dan Webster (R-FL) provided a perfect example … asking witness Judith Curry what causes ice ages (Milankovich cycles, which we’ve known for nearly 100 years), so that he could make the point that natural factors caused past climate changes – a point that usually leads to a common logical fallacy (presented here in cartoon form).
Webster proceeded to claim it was “the standard belief of most scientists” in the 1970s that the Earth was headed into an ice age.
This has been discussed at length on this blog, see especially this guest post. It is indeed true that back in the 1960s (and a little ways into the 70s) climate scientists considered cooling as well as warming for future scenarios. As Dana points out in his post, this was partly due to the consideration of aerosols (dust) that might cause a cooling effect sufficient to push us into an ice age. But it has been understood for much longer that the most likely scenario was not cooling, but warming, if we keep putting greenhouse gasses into the atmosphere.
<li><strong>Ben Jervey</strong> at Desmog: <a href="https://www.desmogblog.com/2017/03/29/house-science-committee-hearing-lamar-smith-michael-mann-climate-consensus-deniers">House Science Committee Hearing Pits Three Fringe Climate Deniers Against Mainstream Climate Scientist Michael Mann</a></li>
Ben nots that the intent of these hearings, despite the alt-reasons given by the chair, was to provide a platform for the tiny number of scientists (plus Roger) with positions that must be regarded as firmly in the science denial camp.
Dr. Judith Curry, a former professor at the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, who has since resigned to focus on her private business, Climate Forecast Applications Network. Curry has admitted to receiving funding from fossil fuel companies while at Georgia Tech, and she is frequently cited and quoted by climate skeptic blogs and fossil fuel-funded politicians for her stance that the climate is “always changing.”
Dr. John Christy, a professor of atmospheric science and Director of the Earth System Science Center of the University of Alabama in Huntsville, and the official Alabama State Climatologist since November 2000, who routinely critiques climate modeling and has sung the praises of carbon dioxide.
Dr. Roger Pielke, Jr., who is not a climate scientist, but a climate science policy writer working at the University of Colorado in Boulder, and who Joe Romm at Climate Progress once called “probably the single most disputed and debunked person in the science blogosphere, especially on the subject of extreme weather and climate change.”
“The witness panel does not really represent the vast majority of climate scientists,” said Rep. Suzanne Bonamici, an Oregon Democrat. “Visualize 96 more climate scientists that agree with the mainstream consensus … 96 more Dr. Manns.”
<li>Dan Vergano at BuzzFeed: <a href="https://www.buzzfeed.com/danvergano/mann-inquisition?utm_term=.vwArzR8GR#.kaXl5RdKR">This Famous Climate Scientist Just Endured A Washington Inquisition</a></li>
Climate science went on trial on Wednesday at a hearing held by Congress’s notoriously grouchy science committee.//
The witness list pitted Penn State climate scientist Michael Mann — a lightning rod for energy industry-funded attacks on scientists for two decades — against two scientists critical of their own field, former Georgia Tech scientist Judith Curry and University of Alabama satellite scientist John Christy, as well as a political scientist, Roger Pielke Jr. of the University Colorado, who has argued against links between climate change and extreme weather. These three climate skeptics had collectively testified 20 times previously at similar Congressional hearings.
As Dan implies, the gang of three deniers, and a few others, have been before this and other panels in the US Congress again and again. Interestingly, the short list of deniers available has grown shorter over the years. There are no new ones — that 97% consensus figure works only if you include everyone. If you look only at younger scientists, it is very hard to find any deniers — so there is some attrition for the usual demographic reasons. But also, at least one denier, Heartland funded alt-Harvard scientist Willie Soon, has been taken off the list because his reputation died an ugly death from self inflicted wounds.
<li>Devin Henry at <a href="http://thehill.com/policy/energy-environment/326336-members-researchers-spar-over-climate-science-at-hearing">The Hill: House Panel Hearing Becomes Climate Change Sparring Session</a></li>
“The current scientific consensus on human-caused climate change is based on thousands of studies conducted by thousands of scientists all around the globe,” committee ranking member Eddie Bernice Johnson (D-Texas) said.
… Michael Mann criticized committee Republicans for their NOAA probe, saying it “is meant to send a chilling signal to the entire research community, that if you, too, publish and speak out about the threat of human-caused climate change, we’re going to come after you.”
Mann sparred directly with Smith, highlighting a Friday article in Science magazine that criticized Smith for speaking at a conference for climate change skeptics. Science magazine is published by the American Association for the Advancement of Science.
“That is not known as an objective writer or magazine,” Smith said.
Mann replied, “Well, it is ‘Science’ magazine.”
This part, which is also discussed in the above referenced piece at the Guardian, was amazing. When Smith called the United State’s primary science journal a biased source, I could hear the sound of jaws dropping in unison across the world.
<li>Rebecca Leber at Mother Jones: <a href="http://www.motherjones.com/environment/2017/03/michael-mann-lamar-smith-house-science-committee">A Scientist Just Spent 2 Hours Debating the Biggest Global Warming Deniers in Congress</a></li>
Michael Mann lamented that he was the only witness representing the overwhelming scientific consensus that manmade global warming poses a major threat.
“We find ourselves at this hearing today, with three individuals who represent that tiny minority that reject this consensus or downplay its significance, and only one—myself—who is in the mainstream,” he said in his opening testimony.
Mann blasted Republicans for “going after scientists simply because you don’t like their publications of their research—not because the science is bad, but because you find the research inconvenient to the special interests who fund your campaigns.” He added, “I would hope we could all agree that is completely inappropriate.”
<li>Emily Atkin: <a href="https://newrepublic.com/minutes/141716/house-republicans-held-insane-hearing-just-attack-climate-science">House Republicans held an insane hearing just to attack climate science</a></li>
The Trump administration has been nothing if not a master class in gaslighting—the art of manipulating people, often through lies, into questioning their own sanity—and its pupils on Capitol Hill have clearly been taking notes. On Wednesday, the Republicans on the House Science Committee held a three-hour hearing on the merits of climate change science, a cavalcade of falsehoods so relentless and seemingly rational that one might well need psychiatric counseling after having watched it.
I’m going to disagree with Emily on the ordering of things. The Republicans were already very good at doing this. It may be that Trump learned from them, or it might just be that governing from the conservative agenda and real estate both involve a lot of gaslighting.
But, she is right; this is gaslighting. EG:
At one point, a Republican on the committee even tried to pin the label of “climate denier” on Michael Mann, a world-renowned climate scientist the Democrats had called to defend mainstream science. Georgia Congressman Barry Loudermilk asked Mann if he though it was possible, even in the slightest, that humans are not the main driver of climate change. Mann said that based on the current data, it’s not possible. Loudermilk concluded: “We could say you’re a denier of natural change.”
It was, overall, a horrendously depressing display of scientific illiteracy, but there were some odd bits of optimism to be found. The witnesses all agreed at various points that yes, the climate is changing and that humans play a role (though they disagreed, contrary to overwhelming evidence, on the magnitude of that role), and they also agreed that the Trump administration’s proposed cuts to Earth-observing systems at NASA, NOAA, and elsewhere are a monumentally dumb idea.
What’s more, perhaps the best point was made by one of the GOP witnesses, Roger Pielke, Jr.: “Scientific uncertainty is not going to be eliminated on this topic before we have to act.”
In other words, not knowing everything is not a justification for doing nothing.
One of the more disturbing moments during the hearing was when Republican representative Clay Higgins asked Mike Mann if he was a member of the Union of Concerned Scientists. At first, I was surprised to hear the answer: “No.” Then, I realized, that if you are a smart witness, often called as a witness, then other than the major professional societies, it is probably better to not be a member of anything.
It was even more shocking when Higgins, who is clearly not the sharpest bullet in the chamber, demanded that Mann provide proof that he is not a member of the Union of Concerned Scientists. Mann indicated that he had already provided his resume, which does not say that he is a UCS member, but would be happy to send a second copy.
Sorry, Mike, that is not proof that you are not a card carrying member of the Union of Concerned Scientists. You will need something better than that. Here, for example, is a valid Not a Member card:
I have placed the YouTube video of the entire hearing at the bottom of the post.
By important, I mean people who have their hands on the levers of power, more or less, in areas that affect energy policy.
I don’t really care if Uncle Bob doesn’t accept climate change. Uncle Bob votes for right wing yahoos anyway, that wasn’t going to change. Why should it matter what Uncle Bob thinks?
Unless Uncle Bob is a top policy actor involve din climate and energy issues at the federal level or in Florida, Nevada, North Carolina, or Ohio. Right?
The Climate Constituencies Project looked at these folks (Uncle Bob’s colleagues as described) to see where they stand on climate change.
… there is an overwhelming level of consensus around the science of climate change among policy actors at the Federal level and in these four swing states. In fact, even with all of this talk of climate denial, opinions have gotten even stronger and the numbers have gone up since summer 2010 when we conducted a previous round of this research. Across the four swing states and the federal level, there are no statistically significant differences in opinions on these questions.
It turns out there is real debate in the area of climate change and energy, but it is about what to do, not that something needs to be done.
When asked about potential policy instruments to address climate change and energy options, however, there was much less agreement. Opinions around a potential cap-and-trade bill were statistically significantly different across the swing states and the federal levels, with policy actors in Florida and at the federal level having much lower opinions than the other states.
A new paper examines what is behind the ~2% of climate change related peer reviewed research that run contrary to widely accepted scientific consensus on climate change to see why those papers are wrong.
There is a scientific consensus that increasing greenhouse gas concentration in the atmosphere causes surface warming, and that CO2 is a major greenhouse gas. This consensus is based on physics. We don’t need to observe the effects of human greenhouse gas pollution to know this. There is consensus that human burning of fossil fuel causes an increase in CO2 in the atmosphere. We don’t need to observe this to know it, because we know how combustion works. But it is relatively simple to measure, and it has been measured, and it is true. There is consensus that the planet’s surface has warmed. This is expected from the physics and the fact that we are increasing atmospheric CO2, but it is also relatively easy to measure, it is measured, and it is true. There are varying levels of understanding the effects of this process, and varying degrees to which the effects of surface warming are thought to cause specific effects. One could probably characterize the scientific consensus as a widespread understanding that surface warming has had and will have a range of effects, with many of those effects being changes in weather patterns or regional climatology (how warm/cool/dry/wet a region generally is across he seasons) arising from a combination of “natural variability” (what would happen without greenhouse gas pollution) and anthropogenic global warming.
It is interesting, then, to see the results of various studies of scientific consensus related to climate change. Two kinds of studies have been done. One asks scientists what they think, the other reviews the scientific literature to see what the peer reviewed papers that address climate change say. In both cases we see a number between 90 (or, really, 95) and 100 percent agreement on the stuff in the paragraph above. It is not surprising that the vast majority of scientists, and the vast majority of research papers, have very similar things to say about climate change. This is not new science, and while climate is very complex, the basics of anthropogenic global warming are well understood. The results of empirical research closely match expectations derived from the physics. It all hangs together pretty well.
What is surprising is to see that 3-6% or so disagreement. Who are those scientists, why do they disagree, what do those papers say?
I would assume that since consensus research takes time, and often looks at several years worth of papers, that some of that non-consensus reflects older thinking and older research. Also, there are climate contrarians, including some scientists, who oppose the consensus for reasons not based on the science. That sort of denial presumably comes from the simple fact that some corporations or wealthy individuals will see reduced profits as we make the inevitable shift away from fossil fuels. So some of that non-consensus may be bought and paid for self interested maneuvering.
Rasmus Benestad, Dana Nuccitelli, Stephan Lewandowsky, Katherine Hayhoe, Hans Olav Hygen, Rob van Dorland, and John Cook, in “Learning from mistakes in climate research” (Theoretical and Applied Climatology) looks at the non-consensus peer reviewed literature.
The paper is here, and author Dana Nuccitelli has a writeup on the paper here. From the abstract:
Among papers stating a position on anthropogenic global warming (AGW), 97 % endorse AGW. What is happening with the 2 % of papers that reject AGW? We examine a selection of papers rejecting AGW. An analytical tool has been developed to replicate and test the results and methods used in these studies; our replication reveals a number of methodological flaws, and a pattern of common mistakes emerges that is not visible when looking at single isolated cases. Thus, real-life scientific disputes in some cases can be resolved, and we can learn from mistakes. A common denominator seems to be missing contextual information or ignoring information that does not fit the conclusions, be it other relevant work or related geophysical data. In many cases, shortcomings are due to insufficient model evaluation, leading to results that are not universally valid but rather are an artifact of a particular experimental setup. Other typical weaknesses include false dichotomies, inappropriate statistical methods, or basing conclusions on misconceived or incomplete physics. We also argue that science is never settled and that both mainstream and contrarian papers must be subject to sustained scrutiny. The merit of replication is highlighted and we discuss how the quality of the scientific literature may benefit from
The researchers found that cherry picking was the most common explanation for the non-consensus papers contrary results. In other words, it is not the case that a small number of paper simply found the physics, or some other aspect of, global warming to be different than other researchers found, or that they were looking at a part of the system that acts differently. Rather, these papers were wrong, and for a specific reason.
We found that many contrarian research papers omitted important contextual information or ignored key data that did not fit the research conclusions. For example, in the discussion of a 2011 paper by Humlum et al. in our supplementary material, we note,
The core of the analysis carried out by [Humlum et al.] involved wavelet-based curve-fitting, with a vague idea that the moon and solar cycles somehow can affect the Earth’s climate. The most severe problem with the paper, however, was that it had discarded a large fraction of data for the Holocene which did not fit their claims.
The authors attempted a replication of that particular research, and found that the model they used only worked for part of the underlying data. The data that were ignored by Humlum et al contradicted their findings.
Another problem identified by Benestad et al is the lack of a consistent sensible alternative explanation for their alleged findings. “…there is no cohesive, consistent alternative theory to human-caused global warming. Some blame global warming on the sun, others on orbital cycles of other planets, others on ocean cycles, and so on. There is a 97% expert consensus on a cohesive theory that’s overwhelmingly supported by the scientific evidence, but the 2–3% of papers that reject that consensus are all over the map, even contradicting each other.”
Are there cultural differences between those who accept and generally understand the current consensus on climate change science and those who don’t? One gets the sense that there is, but it is possible to explore this in more detail.
I took the public Twitter profile descriptions, written by individual Twitterers, from two different Twitter lists that I maintain, and made word clouds out of them. The first is a list of “Global warming deniers.” People get on this list when they actively deny climate change science in Twitter exchanges with me (or that I observe). There are 309 members as of this writing. The second list is “Climate Change Science,” and includes climate scientists, scientists in cognate areas, and journalists or science communicators, a few activists, etc. That is the go-to list if you want to keep up on current climate science related news. There are 236 members as of this writing.
I made these tag clouds at the suggestion of Michael Mann, who thought that it might be interesting to look at the differences, if any, in how the two groups tend to characterize themselves.
Here is the word cloud for the “Global Warming Deniers” list:
Here is the word cloud for the “Climate Change Science” list:
I could comment on these two word clouds, but what would be the point. Word clouds kind of speak for themselves. So just gaze at them for a while.
Well, OK, I will comment on the word “love” in the denier cloud, to provide some context. Members of this list indicated that they love golf, cooking, this great country, Labradors, wine, ale, Jesus, family, church, shooting, all things scientific, restaurants, Fox News, Reagan, sea urchins, various spouses, and other things to drink or do. For “hate” we have liberal lies and big government, but there wasn’t enough hate to show up in the tag cloud.
Professor Mann pointed out to me that this may be understood in the context of the Yale Project on Climate Change Six Americas Study (see graphic at the top of the post). That study is summarized in this video:
So, these word clouds summarize the Six Americas in simplified form, which we could call, I suppose, “America A” and “America B” to avoid confusion.
Enough! That’s Peter Doran’s opinion on the “debate” about a scientific consensus on climate change. There clearly is one — a strong one. So why do the public and the politicians think otherwise? Why the big disconnect between what the vast majority of scientists know to be fact, and what the public thinks. Dr. Doran blames the way media reports on science, and he blames a few of the loud voices on the right. He presents an idea to change a lot of the minds of people who deny the scientific consensus on climate change which will hopefully lead politicians to action. Peter Doran is a professor of Earth and Environmental Sciences at the University of Illinois at Chicago. He has published over 80 articles in the academic literature about the polar regions, lakes, ecology and climate change.
This is a big thing. Starting just now, 97 different top experts on climate change, starting with Michael Mann (author of this book), one per hour, will have a say about the consensus. This is being run by Skeptical Science.
Research has shown that when people are aware of the expert consensus, they’re more likely to accept the fact that humans are causing global warming, and also more likely to support taking action to address the problem. Hence the consensus gap is a significant roadblock preventing us from tackling global warming.
To help close this gap, the website Skeptical Science has launched a 97-hour social media event starting today, 9/7. Each hour, the site will publish a relevant quote from a climate scientist, along with a playful caricature drawn by Skeptical Science founder and University of Queensland researcher John Cook. Each caricature lists the scientists’ name, title, expertise, and academic institution.
You can see the event unfold in an interactive 3D animation HERE. (Just pin the scientist down with your mouse cursor and make them talk!)