Guest commentary by William R. L. Anderegg, Jim Prall, Jacob Harold, Stephen H. Schneider
Note: Before Stephen Schneider’s untimely passing, he and his co-authors were working on a response to the conversation sparked by their recent paper in the Proceedings of the National Academy of Sciences on climate change expertise. One of Dr. Schneider’s final interviews also addresses and discusses many of the issues covered here.
We accept and rely upon the judgment and opinions of experts in many areas of our lives. We seek out lawyers with specific expertise relevant to the situation; we trust the pronouncement of well-trained airplane mechanics that the plane is fit to fly. Indeed, the more technical the subject area, the more we rely on experts. Very few of us have the technical ability or time to read all of the primary literature on each cancer treatment’s biology, outcome probabilities, side-effects, interactions with other treatments, and thus we follow the advice of oncologists. We trust the aggregate knowledge of experts – what do 97% of oncologists think about this cancer treatment – more than that of any single expert. And we recognize the importance of relevant expertise – the opinion of vocal cardiologists matters much less in picking a cancer treatment than does that of oncologists.
Our paper Expert Credibility in Climate Change is predicated on this idea. It presents a broad picture of the landscape of expertise in climate science as a way to synthesize expert opinion for the broader discourse. It is, of course, only a first contribution and, as such, we hope motivates discussion and future research. We encourage follow-up peer-reviewed research, as this is the mark of scientific progress. Nonetheless, some researchers have offered thoughtful critiques about our study and others have grossly mischaracterized the work. Thus, here we provide responses to salient comments raised.
Definition of groups: The first of four broad comments about our study examines the relevancy of our two studied groups – those Convinced of the Evidence that much of the warming of the last half century is due in large part to human emissions of greenhouse gases, as assessed by the IPCC, which we term “CE,” and those who are Unconvinced of the Evidence (“UE”). Some have claimed that such groups do not adequately capture the complexity of expert opinion and therefore lose meaning. To be sure, anthropogenic climate change (ACC) is an immensely multi-faceted and complex area and expert opinion mirrors this complexity. Nonetheless, society uses simplifications of complex opinion landscapes all the time (e.g. Democrat versus Republican for political views) that don’t “lose their meaning” by ignoring the complexity of nuanced differences on specific topics within these broad groups.
The central questions at hand are: are these groups (1) clearly defined, (2) different in views of ACC, (3) reasonably discrete, and (4) in the main mutually exclusive? Our definition of groups, based entirely in the case of the UE group on their self-selected, voluntarily signed statements and petitions expressing various versions of skepticism about ACC, is clearly defined in the published paper. The strongest evidence indicating that our CE and UE groups satisfy the second and third criteria is that only three of 1,372 researchers fell into both groups—and in two of those cases, the researcher unwittingly added themselves to a statement they did not in fact support. Thus, if only one researcher of 1,372, or 0.07%, legitimately falls into both of our groups, this suggests that the two groups both differ starkly and are discrete. Any statistical analysis would be only trivially altered by having three redundant members of the cohort. Furthermore, the CE and UE groups are coherent, as around 35% of signers in each group also signed another statement in that set.
Another researcher suggests that his views have been “misclassified” by our inclusion of older public statements, as he signed a 1992 statement. Using a sweeping set of public statements that cover a broad time period to define the UE group allows us to compile an extensive (e.g. make an effort to be as comprehensive as possible) dataset and to categorize a researcher’s opinion objectively. However, were we to reclassify this researcher, it would only strengthen our results as then none of the top fifty researchers (rather than one researcher, or 2%) would fall in the UE camp.
Others have contended that the only experts we should have analyzed were those researchers involved specifically in detection and attribution of human-caused climate change. Importantly, much of the most convincing evidence for ACC comes from our understanding of the underlying physics of the greenhouse effect, illuminated long before the first detection/attribution studies, and these studies provide only one statistical line of evidence. The study could have been done in this manner but let us follow that logic to its conclusion. Applying this stricter criterion to the CE list does cause it to dwindle substantially…but applying it to the UE list causes it to approach close to zero researchers. To our knowledge, there are virtually no UE researchers by this logic who publish research on detection and attribution. Following this logic one would have to conclude that the UE group has functionally no credibility as experts on ACC. We would, however, argue that even this premise is suspect, as ecologists in IPCC have done detection and attribution studies using plants and animals (e.g. Root et al. 2005). Finally, applying a criterion such as this would require subjective judgments of a researcher’s focus area. Our study quite purposefully avoids making such subjective determinations and uses only objective lists of researchers who are self-defined. They were not chosen by our assessment as to which groups they may or may not belong in.
Some have taken issue with our inclusion of IPCC AR4 WGI authors in with the CE group, in that the IPCC Reports are explicitly policy-neutral while the four other CE policy statements/petitions are policy prescriptive. However, we believe our definition of the CE group is scientifically sound. Do IPCC AR4 WGI authors subscribe to the basic tenets of ACC? We acknowledge that this is an assumption, but we believe it is very reasonable one, given the strength of the ultimate findings of the IPCC AR4 WGI report. We classify the AR4 WGI authors as CE because they authored a report in which they show that the evidence is convincing. Naturally, authors may not agree with everything in the report, but those who disagreed with the most fundamental conclusions of the report would likely have stepped down and not signed their names. The presence of only one of 619 WGI contributors on a UE statement or petition, compared to 117 that signed a CE statement, provides further evidence to support this assumption. Furthermore, repeating our analysis relying only on those who signed at least one of the four CE letters/petitions and not on IPCC authorship yields similar results to those published.
No grouping of scientists is perfect. We contend that ours is clear, meaningful, defensible, and scientifically sound. More importantly, it is based on the public behavior of the scientists involved, and not our subjective assignments based on our reading of individuals’ works. We believe it is far more objective for us to use choices by scientists (over which we have no influence) for our data instead of our subjective assessment of their opinions.
Scientists not counted: What about those scientists who have not been involved with the IPCC or signed a public statement? What is their opinion? Would this influence our finding that 97% of the leading researchers we studied endorse the broad consensus regarding ACC expressed in IPCC’s AR4? We openly acknowledge in the paper that this is a “credibility” study and only captures those researchers who have expressed their opinions explicitly by signing letters/petitions or by signing their names as authors of the IPCC AR4 WGI report. Some employers explicitly preclude their employees from signing public statements of this sort, and some individuals may self-limit in the same way on principle apart from employer rules. However, the undeclared are not necessarily undecided. Two recent studies tackle the same question with direct survey methods and arrive at the same conclusion as reached in our study. First, Doran and Kendall-Zimmerman (2009) surveyed 3,146 AGU members and found that 97% of actively publishing climate researchers believe that “human activity is a significant factor in changing mean global temperatures.” A recently published study, Rosenberg et al (2010), finds similar levels of support when surveying authors who have published during 1995-2004 in peer-reviewed journals highlighting climate research. Yes, our study cannot answer for – and does not claim to – those who have not publically expressed their opinions or worked with the IPCC, but other studies have and their results indicate that our findings that an overwhelming percentage of publishing scientists agree with the consensus are robust. Perfection is not possible in such analyses, but we believe that the level of agreement across studies indicates a high degree of robustness.
Publication bias: A frequent response to our paper’s analysis consists of attributing the patterns we found to a systematic, potentially conspiratorial suppression of peer-reviewed research from the UE group. As of yet, this is a totally unsupported assertion backed by no data, and appears untenable given the vast range of journals which publish climate-related studies. Notably, our publication and citation figures were taken from Google Scholar, which is one of the broadest academic databases and includes in its indexing journals openly receptive to papers taking a different view from the mainstream on climate. Furthermore, recently published analysis (Anderegg 2010) examines the PhD and research focus of a subsample of the UE group, compared to data collected by Rosenberg et al. 2010 for a portion of the climate science community publishing in peer-reviewed journals. If the two groups had similar background credentials and expertise (PhD topic and research focus – both non-publishing metrics), it might indicate a suppression of the UE group’s research. They don’t. The background credentials of the UE group differ starkly from that of the “mainstream” community. Thirty percent of the UE group sample either do not have a documented PhD or do not have a PhD in the natural sciences, as compared to an estimated 5% of the sample from Rosenberg et al; and nearly half of the remaining sample have a research focus in geology (see the interview by Schneider as well).
“Blacklist”: The idea that our grouping of researchers comprises some sort of “blacklist” is the most absurd and tragic misframing of our study. Our response is two-fold:
- Our study did not create any list. We simply compiled lists that were publicly available and created by people who voluntarily self-identified with the pronouncements on the statements/letters. We did not single out researchers, add researchers, drop researchers; we have only compiled individuals from a number of prominent and public lists and petitions that they themselves signed, and then used standard social science procedure to objectively test their relative credibility in the field of climate science.
- No names were used in our study nor listed in any attachments. We were very aware of the pressure that would be on us to provide the raw data used in our study. In fact, many journalists we spoke with beforehand asked for the list of names and for specific names, which we did not provide. We decided to compromise by posting only the links to the source documents – the ‘raw data’ in effect (the broader website is not the paper data), where interested parties can examine the publically available statements and petitions themselves. It is ironic that many of those now complaining about the list of names are generally the same people that have claimed that scientists do not release their data. Implying that our list is comparable to that created by Mark Morano when he worked for Senator Inhofe is decidedly unconvincing and irresponsible, given that he selected individuals based on his subjective reading and misreading of their work. See here for a full discussion of this problematic claim or read Schneider’s interview above.
In sum, the various comments and mischaracterizations discussed above do not in any way undermine the robust findings of our study. Furthermore, the vast majority of comments pertain to how the study could have been done differently. To the authors of such comments, we offer two words – do so! That’s the hallmark of science. We look forward to your scientific contributions – if and when they are peer-reviewed and published – and will be open to any such studies. In our study we were subjected to two rounds of reviews by three social scientists and in addition comments from the PNAS Board, causing us to prepare three drafts in response to those valuable peer comments that greatly improved the paper. We hope that this response further advances the conversation.
References
Anderegg, W.R.L. (2010) Moving Beyond Scientific Agreement. Climatic Change, 101 (3) 331-337.
Doran PT, Zimmerman MK (2009) Examining the Scientific Consensus on Climate Change. Eos Trans. AGU 90.
Root, T.L. et al. (2005) Human-modified temperatures induce species changes: Joint attribution. PNAS May 24, 2005 vol. 102 no. 21 7465-7469
Rosenberg, S. et al (2010) Climate Change: A Profile of U.S. Climate Scientists’ Perspectives. Climatic Change, 101 (3) 311-329.
Gavin
When you said “Mining the climate model databases” did you mean analysing the output of the GCM’s in order to find relationships in the variables? I was thinking in particular to your point over a CoS regarding making the science more policy relevant, sort of like trying to find what variables have impacts on the policy decisions and how they impact them. I’m not sure I understood correctly though. Could you give an example of what the software constraints are?
What do you think of an open source GCM (clear climate GCM)? I know it would be wraught with difficulties since, for example, all the current GCM’s I know of run on super computer’s that have a lot more computing power than…. my desktop. However I could see an architecture that allowed a user to run a standard run (for any given study) and upload the result (or partial result) when it is complete. I believe there was something similar for this with the SETI program. It could even be used to give some more policy relevant tools to politicians, although I’m sure we could debate what form those tools should or would take (I’m partial to them having to download the code, make it compile and make sure their envr variables are correctly set). In particular, as an engineer with an aerospace simulation company, it is a project that someone with skills like mine would be well suited to help with.
[Response: Let’s think about an example. Imagine I was interested in storm systems in the North Atlantic and how they were represented in models. I would like therefore to aggregate all of the examples of a ‘storm’ in the models and observations and get some average cloudiness, rainfall rate, cloud-top height, etc and build up a 3D ‘generic storm’ for each model and the data. Sounds easy right? But to do this right now would involve downloading terabytes of data processing it very laboriously and doing it separately for every single model simulation. But that would be very useful information which currently exists in theory, but not in practice. Finding ways to crowd source that kind of thing would be a huge contribution.
On your second point, I did think about suggesting an open source GCM, but I decided against it. The problem there is that each component in a GCM is very much a state of the art domain issue. You really need to understand the issues in modelling convection to do it justice, the same for radiative transfer, or ocean mixing. One could obviously take an existing GCM and re-factor it (as clearclimatecode did for GISTEMP) but unless that was done in tight collaboration with an existing group, maintenance of that code to deal with new advances would be very hard. If the aim was somewhat different – a web-based portal for the lay public or for educators (a la Modtran) – something like EdGCM perhaps, then it would be doable. But one would need to be very clear about what was being attempted. Maybe others would like to chip in here? – gavin]
JeffId @97,
Have you actually read the post by the authors above, or for that matter Didactylos’ comments to RomanM made here? Seems not, seems that you are happy to blindly support RomanM.
IMO, the authors of the paper have been very open to critique. Now if you think that you or CA can do better, please do go ahead an publish a paper in PNAS demonstrating the impact of the alleged error on the results. Anything less simply amounts to whining and obfuscation from the inconvenient truths underscored by the findings in this paper. Whining also wastes everyone’s time and does not advance the science.
And, in Prall’s post above he did concede and acknowledge that there were some minor errors– almost every paper has them. So please stop arguing strawmen and trying to suggest that he and his co-authors (including Schneider) are not “credible”.
Let us look at this another way, if you and RomanM wish to be “credible” scientists, then the onus is on you to publish a comment on the PNAS paper.
I see you didn’t have the courage to publish my later comment. And you continue to miss the point. It is not important that the names were public nor that the signatories performed a public action.
The canons of research require, for very good reason, that you do not associate individuals with research outputs.
To say otherwise is anti-science.
[Response: Nonsense. If I am doing research on the impact of Gordon Brown on economic policy in Europe using his public speeches, I think it would be a little weird not to mention his name in the resulting paper. If I wanted to aggregate his impact along with all other heads of state in Europe for the same time period (which I am pretty sure is also in the public domain), would I be expected to say ‘a sampling of heads of state’ rather than just give a list of my ‘research subjects’? This is just bogus. (PS. continued whines about how you are being repressed will be met with persistent links to this youtube video. Either add something substantive (politely) or don’t bother). – gavin]
Bob (Sphaerica) @66 says:
“We are talking about the need to recognize and respect the statements made by experts..”
I agree and said so in my reply to you in #65. “Respect” not “trust’ are the operative words.
Then you say:
“You’ve tied yourself in knots over picayune phrasing, and keep missing the point”
I originally commented on the following statement in the article: “we trust the pronouncement of well-trained airplane mechanics” And I have remained consistent to answering it throughout. IMO the statement mixes associations that are not correct and gives a false impression,
Please be informed that an article needs to crab its audience in the first few lines. If it doesn’t it won’t get read. I offered my feedback in good faith. Please receive it as such.
65 Patrick 027 @70 says:
“Aircraft are not allowed to take off unless their maintenance/repair is current and in order. – Sounds like the people who wrote those rules had some good judgement. :)”
The people that wrote the rules judged that we needed more than expert opinion and judgment so implemented the process of engineering standards and regs.
Donna @71 says:
“I’ll make you a bet that there are differences of opinion as to what exactly the words in the rules and standards mean”
I will not bet because I do not want to take your money. There is no opinion required. If a part is designed for so many hours of operation then it will be replaced. Repairs and maintenance are carried out by the book with designated tools and procedures which are signed off on, documented and audited.
sambo says: 5 August 2010 at 12:02 AM
Does anyone from either side care to suggest where efforts like this could be most beneficial?
If you’ve got inclination but little time you might consider contributing some flops to ClimatePrediction.net. Here at home the multi-purpose server runs it using “idle cycles.”
The only feedback I get is
28890 dbostrom 39 19 59920 46m 4328 R 92.7 9.3 8:41.74 hadsm3_um_6.08_
but I don’t really care. The machine uses about 30 extra watts over what it would if it were allowed to rest. Power here is cheap and we’re about 80% hydro so no big deal. If you’re on coal, maybe a different matter.
BTW, where’s Tom Fuller’s outrage over folks having their email purloined and then published? I actually think what you’ve done borders on being actionable. It unquestionably violates the UK’s and EU’s Data Privacy Acts. Care to give some legal advice on how the law treats email theft, Tom?
Tom Fuller,
[edit – be nice]
The idea behind the selection process was not that the authors labeled anyone, but rather that the groups labeled themselves (in the public domain). Whether or not the methodology to take these public lists and create a statistical representation of the population was appropriate is one matter, but the whole “blacklist” line is nonsensical and unconvincing. If someone signs a petition saying ‘global warming is a hoax’ that is available for the world to see, then the co-authors of this paper are not the ones labeling them…they have made it clear on their own accord what their position is.
Can this just be repeated, so everybody gets it?
Indeed the whole point about signing such letters (whether they be a set of Nobel Prize winners, or scientists, or doctors or whomever) is to imbue them with authority based on the authority of the signers. It is therefore completely legitimate to assess that implied authority – just as people have done less systematically for any number of petitions. – gavin]
That will suffice nicely for calming anybody getting the vapors over the supposed blacklist. Does anybody need it explained further? Surely not?
It’s oh so interesting to see the many complaints about the names of people being available on a website. Interesting, because I am certain that if the names were NOT available, there would be loads of moaning about the data not being made freely available…or does free access to the raw data no longer count when it is sociological research?
Tom Fuller’s complaint about the supposed blacklist is and remains laughable. If being mentioned indirectly as a UE is so harmful to one’s career, why is openly and willingly signing a petition which is published in the WSJ NOT harmful? Tom? Any credible counter-argument?
#89 Lynn Vincentnathan
Was it wise to invade Iraq because it was believed they had Weapons of Mass Destruction?
And does your “BEST OF ALL WORLDS scenario” include carpeting the landscape with wind turbines?
From:
http://www.climatesciencewatch.org/index.php/csw/details/schneider-interview-climate-expert-credibility/
“Schneider: The main thing I want people to remember is that when we’re talking about expertise, we’re not talking about expertise in what to do about a problem. That is a social judgment and every person has the same right to their opinion as any person in climate. However, we are talking about the relative likelihood that there could be serious or even dangerous changes. Because before you even decide how you want to deploy resources as a hedge against a wide range of important social problems, you have to know how serious the problems are. All we’re trying to do in science is give the best estimate that honest people with a lot of evidence can, about the relative risks, so they can make wise decisions in their own lives and in who they elect about how we should deal with it.”
Yet courts sometimes intervene when parents won’t take their children to a doctor. At the least, sanity is required on the part of the voting public, and honest government is necessary. We have neither.
Schneider also says: “If you have a heart arrhythmia as I do, and I also have a cardiologist, and you also have an oncological problem as I do, I’m not going to my cancer doc to ask him about my heart medicine and my cardiologist to ask about my chemo, I’m going to the experts. Who’s an expert really matters.”
But Professor Schneider knows enough about medicine to know that a cardiologist works on hearts and an oncologist works on cancer. The voting public in the US does not know enough about science to distinguish wattsupwiththat from realclimate. More people go to the equivalent of a witch doctor than to a real doctor. It isn’t that they can’t distinguish a cardiologist from an oncologist. They can’t distinguish a preacher or a snake oil salesman or a hospitalized schizophrenic from a medical doctor. Ignorance at that level is as good as mental illness. They keep repeating the same wrong behavior, expecting different results. Trying to point out the world’s best cardiologist is pointless.
Jim (re 56)
Thanks for answering. Let me address “aggregate” first. It’s meaning is represented by “a sum, mass, or assemblage of particulars” at http://dictionary.reference.com/browse/aggregate. Notice I don’t use the term “definition”, which has too many meanings.
By aggregate I simply meant “collection of”. I may be creating straw men but my impression of your scientific community is that it believes that the collection of peer reviewed papers is the only “scientific knowledge”. I am not a fan of Thomas Kuhn’s “Structure of Scientific Revolutions” ( See Heinz Post’s “General correspondence principle”) but his picture of scientific progress points out vividly how science in general is not simply aggregation of knowledge parcels.
[Response: I do not believe that peer reviewed journals contain the totality of scientific knowledge, and I’m not in any way arguing that the latter is akin to a stamp collection.–Jim]
I understand that Unger et. al. and Ramana et. al. have different approaches but they both have information on one common topic – the effects of shipping on climate. I haven’t actually seen the full Ramana paper but I was hoping an “expert” might be kind enough to help me form a judgement, with the object of pressing sensible policies on policy makers.
Your reply was not very helpful. It amounts to saying the papers are apples and oranges and hides what your judgement on shipping might be. This echoes what a distinguished environmental journalist remarked about climate scientists “they knew but they didn’t tell us”.
[Response: No, that’s not what I was saying was apples and oranges. That referred to comparing the question addressed by Anderegg et al, with the one you raised, which are of very different scope, level of scrutiny, and societal importance. And nobody I know has knowledge they’re hiding. –Jim]
I know you’ve all had a hard time from the deniers but instead of saying “aside from questions of the weights of the evidence thereon” why don’t you just tell us your assessment. If not, why not?
[Response: Because I don’t have one, as I know nothing about it. If I had an informed one, I’d give it, believe me.–Jim]
P.S. I found Unger et. al. very helpful indeed.
TF 92: In this charged atmosphere it will serve as an impediment to their careers. As some of the letters and petitions you use as reference are fairly innocuous, there are many scientists who do not consider themselves climate deniers who have now been named as such by your paper.
BPL: If people sign conservative open letters, it’s legitimate to call them conservative. If people sign liberal open letters, it’s legitimate to call them liberal. And if people sign climate denier open letters, it’s legitimate to call them climate deniers. Deal with it. They “outed” THEMSELVES.
Allegations of “violations of privacy” are utterly ridiculous. These analyses are conducted on publicly available information. Publicly available information about individuals is *explicitly exempted* from the protection of privacy in the Code of Federal Regulations for the protection of human subjects: http://www.hhs.gov/ohrp/humansubjects/guidance/45cfr46.htm
Re: Tom Fuller #92
“I actually think what you’ve done borders on being actionable. It unquestionably violates the UK’s and EU’s Data Privacy Acts.”
I tried posting earlier but got an error and then a duplicate warning. Trying again.
I am struggling to see how the EU/UK Data Protection Directive/Law applies to scientific publications in the US. If so, then I’ll happily post an analysis.
Gavin, I don’t understand your reluctance to allow the guideline that states that only info germane to the research should be released and that all other info should be protected. (Or maybe, I do understand how the authors could have allowed it.) To wit, sharing names of research subjects with professionals is ok; posting a link to a list of names is not. If you needed any proof of the wisdom of this guideline, this brouhaha provides plenty of it. When I say “blanket denials” I don’t mean to be polemical or insulting toward the authors; I merely am frustrated that they have not specifically answered the question: Why was it necessary to your study’s objectives to do so? Did they discuss their study in light of these guidelines, or with individuals familiar with these issues? If so, how did they arrive at the conclusion that publiciZing the identities of their subjects within their own study (via the links, etc.) was necessary to examine what the study set out to examine? None of these questions are answered by their response, ” it was public anyway” or “we have to share the data.” As mentioned and as the guidelines point our, personally identifiable data may be shared only with other professionals, only excepting cases in which you need to know specific identities in order to understand the results of the study (or you receive consent to do so, etc.)
[Response: As a commenter mentioned above, examining public statements by public figures (by their own choosing), does not make those people ‘research subjects’ in any sense relevant to your comments. You might as well ask that the authors names be left off scientific papers because that is publicly identifiable information. None of those rules cover info that is already in the public domain. And please note this is not ‘my’ study. Anderegg et al asked if we would host their response and after some back and forth, we said yes. – gavin]
Vincent wrote: “Allegations of ‘violations of privacy’ are utterly ridiculous. These analyses are conducted on publicly available information.”
The important thing to realize here, is that these ridiculous allegations that are repeated by one commenter after another, often in very similar language, are scripted talking points that are being spoon-fed to “grassroots” denialists by the fossil fuel industry-funded denialist propaganda machine.
They are not coming from people who have taken the time to read and understand the study and form their own conclusions about it as the result of independent thought. They are coming from people whose modus operandi is to accept without question whatever the denial machine tells them, and then obediently repeat it on blogs everywhere.
And they call themselves “skeptics” for doing just that.
simon abingdon wrote: “And does your ‘BEST OF ALL WORLDS scenario’ include carpeting the landscape with wind turbines”
The commercially exploitable wind energy resources of only FOUR midwestern states is sufficient to produce more electricity than the entire USA uses.
Concentrating solar thermal power stations on FIVE PERCENT of the USA’s deserts could likewise produce more electricity than the entire USA uses.
There is no need to “carpet the landscape” with anything.
Attacking renewable energy technologies with such absurd claims is of equal importance as denial of AGW to the fossil fuel industry-funded obstructionists. And will probably become more important to them as AGW denial collapses in the face of the obvious ongoing effects of global warming, climate change and biosphere destruction.
#82, Didactylos, #88, Maple Leaf.
The intent of my example was to point out to you that the procedure used by the authors to quantitatively summarize the differences between the most prolific publishers in each contains a substantial bias in favor of the larger group when applied to two groups that have identical characteristics. It follows from this that in other cases, the effect will be the same when the groups differ. The results are distorted – some of the difference is actual difference between the two populations and some due to the sample size and you can’t tell how much is due to either source.
To further apply a statistical test on the results as a purported evaluation of the difference in the populations is incorrect. My criticism of this does not fall in the “how the study could have been done differently” category. It is simply not the analytically correct thing to do. Using the test results to substantiate conclusions is inappropriate.
Suppose you are comparing two populations in a case where the distributions are severely skewed and there are a substantial number of extreme values. For other practical reasons, the sample sizes you collected may be unequal, say 500 in one and 1000 in the other. If I wish to compare the details of the distribution of the more extreme values, just choosing the largest 50 from each creates the problem that we have been discussing. One approach to correcting the imbalance could be to first place the two samples on the same size footing. How? By sub-sampling 500 observations randomly from the larger group first and then comparing the top fifty from each. This eliminates the size imbalance effect, but does introduce an effect due to the random selection. The latter can be dealt with by repeating this multiple times (easy to do with computers).
It is my opinion (from the first two sentences in the quoted passage) that this was the intent of the authors, but they skipped the very important sub-sampling step.
There is no single “credo” of global warming of which you are must be either convinced or unconvinced. Rather there is a continuum of observations, predictions, projections, explanations, evidence, etc. It seems reasonable that within the climate science community there must be a range of views from “superconvinced” to “completely unconvinced”. Defining the two groups as the authors did based on the expression of an opinion of various individuals with respect to the setting of policy seems specious with regard to scientific credibility.
However, given their definition, it is not at all surprising that the numbers in the CE group as defined for the paper should be considerably larger than those in the UE group. Over the roughly 35 year period of the AGW movement, there has been a concerted effort to stifle contrary opinions and public debate on the issues (the science is settled, consensus exists) and to vilify anyone who may disagree with any portion of the “evidence” (demeaning names, “deniers”, mental illness of denial conferences, throw skeptics in jail, shills for big oil, flat earthers… including the paper currently under discussion).
Within the insular environment created by this consensus building, it is very unlikely that students in climate science will buck the system. Doing so would make it difficult to get research money and build a career. Only someone who has been in the system longer and is more established can afford to publicly go on record that certain public courses of action are not suitable given their personal view of state of current climate knowledge. So finding more UE’s is not so easy in today’s universities. Notice that in the paper, the authors state that UE individuals tend to be older than CE’s, a fact which is consistent with the above observation.
How does this affect the data in the paper? More individuals in the CE population means more papers written in “official” climate journals means more citations for the earlier works of that group and for their peers. Some of the papers by highly visible scientists will end up with an inordinate number of cites. Do these cites indicate high quality work? In some cases, yes – there are some very capable individuals doing climate science. However one should not confuse the number of citations as incontrovertible evidence of that.
Gavin, 1) I know this isn’t your study.
2) If they’re not “research subjects”, then you’re saying this wasn’t an exercise in social science, which I don’t think you’re saying.
3) As the guidelines point out, rules of confidentiality do in fact apply, even to information gleaned from the public domain or other public records. If you or the authors think this is unreasonable, feel free to take it up with the ASA.
4) But ok, let’s concede for a minute what you say: that they’re not “research subjects” whose identities deserve protection, because they’ve willingly made statements in the public domain. OK, then why didn’t the authors just publish the names? Why did they find it necessary to explain, as they do above, “No names were used in our study nor listed in any attachments. We were very aware of the pressure that would be on us to provide the raw data used in our study. In fact, many journalists we spoke with beforehand asked for the list of names and for specific names, which we did not provide. We decided to compromise by posting only the links to the source documents – the ‘raw data’ in effect (the broader website is not the paper data), where interested parties can examine the publically available statements and petitions themselves.”
If there’s no issue with privacy, why didn’t they give the names to journalists? Maybe we could say they’re going above and beyond the call by not including the names in the study, but then their “compromise” (i.e. providing the links) is no compromise at all! They might as well have published the names in the study proper, for all the good their compromise has done them.
Nor does their “damned if you do share data, damned if you don’t” explanation a valid defense. Nothing in the ASA guidelines prevents them from providing their raw data to relevant professionals and scientists (not journalists, ofc). Just dumping their raw data for all to see doesn’t cut it. That’s acceptable if you’re studying ice cores and tree rings – not people.
As you can see, I’m having a hard time lining up the authors’ stated intentions with their actions – and I’m sure I’m not the only one.
[Response: Well, on #3, nothing was confidential, so no confidentiality rules apply. This point is really very simple. For instance, a google search will quickly reveal that Lindzen signed a number of these letters, and that his CV and publication lists are also online, so someone looking to judge his credibility will be very impressed. The same information is available for me (though whether you are equally impressed is of course unpredictable), or for any of the other signers of any other open letter. As for why the authors didn’t want to focus on specific names in interviews, you will have to ask them, but I think it’s very likely to have been precisely for the reason that they wanted to make a more general point, rather than just personalising it to a few key names. It isn’t the point the Lindzen has a more impressive publication list than me, but rather that the number of people who keep saying that there is no problem are vastly less qualified on average than the people who are saying there is a problem. This is so obvious that no formal study should be needed at all. The Cato letter even had someone from the Reich’s Orgone Research institute for instance.That was really scraping the bottom of the barrel… ;) – gavin]
90 (Jim Prall),
I looked at your site and couldn’t find a contact e-mail. I tried to send a note to you (with a correction) through RC, but have no way of knowing if you got it.
How can you be contacted with corrections for your page?
Everyone, please forgive my lack of civility here, but I find it entertaining, almost side splitting, that Tom Fuller is so vehemently and determinedly championing the rights to privacy of a small group of noble scientists… when he’s published a book using stolen, private e-mails to publicly castigate a small group of noble scientists.
You just can’t make this stuff up. Wow.
RomanM: I’m not responding to conspiracy theories about “a concerted effort to stifle contrary opinions and public debate”. That’s just pure, unmitigated nonsense.
As for your proposed method, the final sample sizes would probably be too small to be meaningful, but feel free to try it and compare the results.
104 (Titus),
We all get what you said. A large number of people have explained the flaw in your reasoning. You’ve chosen in numerous posts to do nothing more than repeat your original point, without elaboration, like a child with his fingers in his ears refusing to listen to something he doesn’t want to hear.
I have of late been greatly offended by the constant misuse of the word “troll” to mean “anyone that doesn’t agree with us (i.e. the core fan club of the blog in question) and dares to post their unpopular opinions.”
This is wrong. People are allowed to disagree, and are not required to acquiesce, and are allowed to post for as long as they maintain and advance an intelligent dialogue.
The reality is that a true troll ignores all responses and simply pounds out what he wants to say without listening, often repeating the same thing over and over, to the point of damaging the entire thread.
You have now, in my book, officially crossed the line into true troll territory because you keep harping on something that dozens of reasonable people have explained to you, while more importantly you keep dodging the point.
The point:
You must read the entire article, even if you don’t like two words in one sentence.
You are not eligible to comment unless you read the entire article.
You cannot claim to be a skeptic if you refuse to read something.
You cannot claim to be educated if you refuse to read something.
You will not be accepted (at least here) as intelligent if you refuse to read something.
And, finally:
You are a troll if you constantly repeat the same point over and over without adding any substance to your remarks.
sa: And does your “BEST OF ALL WORLDS scenario” include carpeting the landscape with wind turbines?
BPL: If hers doesn’t, mine sure does.
ROI @119,
You are misunderstanding this completely.
2)this is not research on people, which is what HRE is all about. It’s about the work that individuals have chosen to make public, and have chosen to publicly identify themselves with. Appealing to research ethics to critique this is a profound misapplication of those ethical principles.
3) how can confidentiality possible apply in cases of voluntary and deliberate public disclosure. I mean, that is the whole point of public petition – ‘hey, here I am, look at me!’
4) And now they do apply confidentiality, appropriately so, and you criticise that too!!
Having now seen the ‘sceptics’ stray into my field I have even more sympathy for climate scientists – the ability of instant internet experts to misinterpret, misunderstand and misapply is quite something.
On the questions about methods raised by RomanN in #64 and #118, I’ve emailed our first author, Bill Anderegg, who did the statistical analysis. He’s the right person to address those comments.
I had my email address on my website until the day the paper came out, at which time I started receiving a huge flood of negative and even hostile emails (though very little of any substance on the issue). This came at a time when I was leaving on holiday and needed to keep my work email address from overflowing and being shut down for exceeding its quota.
Fortunately, the wave of hostile emails came and went, and now that I’m back from vacation I’m mostly caught up on work-related correspondence. I can put my email address back on my climate website again for feedback.
#124 Barton Paul Leveson
“If hers doesn’t, mine sure does”
BPL, your characteristic candour is always refreshing. I only wish some of those who would dismantle our civilisation were as straightforwardly honest.
(BTW no reply from Lynn yet as to whether she thinks it was wise to apply the precautionary principle in deciding to invade Iraq).
[Response: Iraq is OT, so is nonsense about dismantling civilisation. – gavin]
126 (Jim Prall),
I understand completely, and it’s one of the reasons I maintain anonymity on the Internet and use a separate yahoo account for such things (that, and the fact that my teenage daughter would be utterly mortified if her friends could see what her father actually says in public, where *gasp* other people can read it… as soon as she’s old enough, the anonymity can drop away).
But, a suggestion: If you open a thread for it on your blog, people can post corrections there as comments (which you can then read and reply to to confirm it was handled, while simply deleting the original comment… if only so the denial camp can’t “do a study counting the number of errors a climate scientist actually made on what amounts to a hobby page.”).
This way, you wouldn’t have to open your e-mail up to unsavory and unwanted intrusions.
OK, Gavin, if we want to start invoking the rules of logic; then the entire paper is an appeal to authority and popularity (let’s call it popular authority). Worthless.
#67 sorry that I don’t have the time to engage real time with you. I’m not a regular posting machine (maybe 2-5 a week), I just happen to be first and am just now getting back. I’m sorry if this upsets you, but it doesn’t make my opinion spam in my opinion. LOL.
#2 “Your assertion that climate scientists have “avoided critical review” is absolutely false. Indeed it is laughably false.”
Hmmm…..How many requests for data were ignored? Why would anyone even have to invoke freedom of information act to obtain scientific data? Every review of climate science has recommended better communication and more transparency. Do you just get your news from Gavin?
#4 “If almost all mechanics say it is true, you probably want to have the work done ASAP.”
Ok, got me there.
#14 and #16
I was making my own metaphor not using the metaphor from the article. I did indeed read and am reasonably confident that I understood the article, basically, an appeal to popular authority. Do I really need to remind everyone that MOST scientists scoffed at the idea of continents moving.
#18: Someone actually read the Wegman report beside me. Cool.
#21 Chris Colose: Very nice. It’s amazing to me that someone like myself who was pointing out GW 30 years ago and realizes that man can have an impact, but merely believes 1)it’s cheaper (more prudent) to adapt than mitigate and 2) the catastrophic capacity of AGW is over estimated; is labeled a “denier”, personally I like “skeptic” better. I am a skeptic, always been a skeptic, and will continue to be a skeptic. I remember a time when being a skeptic was a good thing among scientific circles, maybe those days will return, maybe not.
[Response: ‘Skeptic’ will become accepted as what it always was, when self-described skeptics start actually being skeptical. – gavin]
127 (simon abington),
Okay, this is something that really, really bugs me. Can RC do a substantive post on this, on the economics behind mitigating climate change? I think it’s really important. If one knocks the “you can’t, it will destroy our way of life” support out of the denial argument, then all resistance to the science becomes moot.
While calling those that believe in the fact of climate change “alarmists,” the deniers bolster their position with actual but false alarmism about economics. To my knowledge, no one in their right mind wants to dismantle our civilization, or anything close, and no democracy or capitalist society would ever succeed in doing so, because the populations simply would not accept it, no matter how important it was or how much they believed the science.
This is a repeated denial exaggeration used to score points.
Further, to my knowledge, studies by economists put the expense at between 1% and 3% of GDP, while there are also clear benefits (such as the fact that one way or the other fossil fuels will run out, so it needs to be done eventually, not to mention the strategic advantages to be gained in not being beholden to the few countries sitting on a key resource that resides primarily in a few unfortunately politically unstable parts of the globe).
Can RC enlist a top economist to write a post on this?
I am sure that ROI and Tom Fuller would be here demanding that the authors open up the data and share information had they chosen to not include the names used in the study. Make information public, you lose. Make information private, you lose.
Unless you are Marc Morano, in which case you can make a list of 700 scientists based on what they said in letters to the editors or random talks, and that’s no problem. Or you are Inhofe, and you can make a literal black list of climate scientists for targeting with federal investigations under a laundry list of statutes. Heck, if Tom Fuller cared so much about confidentiality, why the heck is he a #$(*U#@$ author on a book whose purpose is to dig into people’s private emails and make sweeping generalizations based on out-of-context quotes? Why didn’t he follow his own guidelines that “The canons of research require, for very good reason, that you do not associate individuals with research outputs”? On the scales of ethics, Fuller’s book is orders of magnitude worse than any imagined ethical issues involved in this study.
For those who object to the statistical methods used in the study: redo it with your own statistical methods. I highly doubt that any reasonable approach will find anything except that the vast majority of scientists working in climate-related fields believe that human emissions of greenhouse gases lead to warming which may lead to harm, and that this majority are more likely to agree with the statements that the study’s authors highlighted as “CE” and disagree with the statements highlighted as “UE”.
-M
SecularAnimist (117) “only FOUR midwestern states‘ devoted to wind generation? Is that an ‘ain’t it wonderful’ or a ‘holy crap’ comment? Which would we take? Illinois, Iowa, Kansas and Nebraska?
Bob @ 121 “I find it entertaining, almost side splitting, that Tom Fuller is so vehemently and determinedly championing the rights to privacy of a small group of noble scientists… when he’s published a book using stolen, private e-mails to publicly castigate a small group of noble scientists.”
Iirc, Fuller gives himself a pass on this because “someone else” published those emails and names. He says he had a copy of the emails first, and agonized over releasing it, but once someone else had put it all in the public domain, he no longer saw any problem with publishing the emails and names in his book or on his blog.
Whatevah, Tom. Whatever.
[edit – yes, but this is not what we want in the comments]
Bob, that, or read the WG3 report. It’s not as if it hasn’t been studied and yes, your numbers are in the ball park. Comparable to what nations of the world have always been paying for military “security”, much of it a lot more uncertain, speculative even, than this.
RomanM,
I see what is going on here. The Anderegg et al. paper is important and the findings troublesome/inconvenient for the ‘skeptics’/contrarians, so it has to be attacked. Just like MBH98 has been attacked ad nauseum (even to this day) by McIntyre et al.. The modus operandi of the ‘skeptics’ is to find an error (any error), probably an insignificant error, and then harp on it for the next 12-years, whilst loudly proclaiming on blogs that Anderegg et al. is “broken”. I’m afraid Anderegg et al. have committed themselves to many years of harassment by the CA crowd for their efforts.
Anyhow, on to some specifics. You say,
“One approach to correcting the imbalance could be to first place the two samples on the same size footing. How? By sub-sampling 500 observations randomly from the larger group first and then comparing the top fifty from each.”
And therein lies the rub, the UE group is simple too small to obtain a sufficiently large sample by applying that approach. No matter how you slice and dice it, they do not have enough publications (and no, not b/c of gate keeping as you might suggest). I’d be surprised if scientists who believe that tobacco does not cause cancer or side-effects of smoking are not serious to have published a comparable number of papers in the reputable literature compared to their colleagues who spend a great deal of time and effort trying to address a serious problem. Which group is advancing the science and improving peoples’ lives? Certainly not those who claim that there is nothing to worry about.
As a prof. once said “Zero plus zero is zero”. The small number of papers and citations in the UE group is simply not large enough to permit the approach that you suggest. But like I keep saying, instead of whining here, please do go and write up your supposed superior method and then publish it as a counter opinion in PNAS. No wonder the “skeptics” do not have many publications, they seem happy to spend to much time pontificating and whining. When Trenberth and Murphy had issues with the Lindzen and Choi paper they spent some time and effort researching, drafting, submitting, and amending their papers in repsonse to reviewers’ critique in which they addresses concerns. Same goes for Foster et al. and Halpern et al. That IS how science works and advances….not by someone whining on a blog.
As for your critique of the classes, please listen to what Prof. Schneider had to say about that.
” Over the roughly 35 year period of the AGW movement, there has been a concerted effort to stifle contrary opinions and public debate on the issues (the science is settled, consensus exists) and to vilify anyone who may disagree with any portion of the “evidence” (demeaning names, “deniers”, mental illness of denial conferences, throw skeptics in jail, shills for big oil, flat earthers…”
You have to be joking. After the antics of Inhofe, Cuccinelli, Monckton, Limbaugh, Beck, Maorano, and McIntyre (e.g., McIntyre’s references to “James Hansen and his disciples have a more jihadist approach”, or McIntyre’s reference to “crack cocaine”), do you really want to try and play the victim card? That is pathetic. Shall we discuss the repeated death threats received by Jones, Mann, Ben Santer, Weaver and other climate scientists? Contrary to your beliefs, the climate science behind AGW/ACC is not a “movement”; however, the organized attack on science by CA (which you are a big fan) and other self-proclaimed ‘skeptics’ is a movement. Big difference my friend, but thanks for letting your true colours and ideology show.
Lindzen, Spencer, Pielke Snr and Christy and other “skeptics” have a fine publication record, so stop trying to suggest that they have been prevented from doing so RomanM. Now you are just being an amplifier for the denial movement by parroting their misinformation. Just who are you? I would like to look up your citations as suggested by you friend Mosh.
And a final illuminating comment from you:
“Do these cites indicate high quality work? In some cases, yes – there are some very capable individuals doing climate science. However one should not confuse the number of citations as incontrovertible evidence of that.”
Please do stop pontificating. If an author/scientists manages to get inferior work published it will not get cited. It may get some brief attention, such as the recent kerfuffel surrounding Lindzen and Choi or G&T, but that is usually where the citations cease, or drop off rapidly. Note, the Anderegg database does not account for those papers which have been published and since refuted– I would exclude those form the database, that would put the “skeptics” in a pickle . Of course, even eminent climate scientists lapse some times, but over the span of their careers the H-index or similar citation indices are a very good metric for quantifying the scientists’ impact in the field and their contributions. Note, the same may not be true in medical labs, where one is typically included as a co-author on any paper published by any one of your colleagues working in the lab. So with that all said, please do tell us which of the CE scientists with a high citation count do not typically produce high quality work.
Now get to work on that paper, hope the results are to your liking :)
Tom Fuller (#86) writes:
“Being public is not the same as being labeled as a climate denier by an IT administrator and a grad student doing what they call ‘research.’”
Can you point out in the paper where anyone is being labelled a “climate denier”? Thanks. And if you have a problem with the PNAS study, you can always seek to publish a rebuttal.
Also, as I understand it, you don’t have a college degree at all. Thus, it seems odd that you’re focusing on credentials. But your lack of qualifications shouldn’t inhibit you from publishing if you have a good argument.
And stating the obvious here, if skeptics (or anyone) don’t want their opinions on climate science to become public, don’t sign public statements. It’s that simple. From my observations, though, skeptics are proud of their stance on climate science and eager to speak out publicly.
John W. says, “OK, Gavin, if we want to start invoking the rules of logic; then the entire paper is an appeal to authority and popularity…”
Wrong. It is not an appeal to authority, but rather a matter of productivity. If the views of the “unconvinced” sector prevent them from advancing the state of knowledge about the climate, that suggests nature is telling us that view is wrong–that is, unproductive. Nature tells us we are on the right track by allowing us to better understand what we are studying. If your prejudices prevent you from understanding, then you had better examine and modify your preconceptions.
Just look at
1)the proportion of actively publishing climate scientists who are convinced that anthropogenic causation is an inevitable consequence of the consensus model of climate change
2)look at the relative publication numbers between the convinced and the unconvinced.
That OUGHT to tell you something.
I would have thought that it would be intuitively clear that a “research subject” is usually someone with whom the researcher actually interacts. Apparently not, from the thread so far.
Perhaps this will clarify:
In biostatistics or psychological statistics, a research subject is any object or phenomenon that is observed for purposes of research. In survey research and opinion polling, the subject is often called a respondent. In the United States Federal Guidelines a human subject is a living individual about whom an investigator conducting research obtains 1) Data through intervention or interaction with the individual, or 2) Identifiable private information (32 CFR 219.102.f). (Lim,1990)
By this guideline, the researchers studied in Prall et al. are clearly not “subjects,” for the reason Gavin has already given several times: the information used was already public.
I’m tempted to editorialize here, but will refrain.
All these people invoking the ghost of Wegener would do well to remember that climate change was not widely accepted until recently. Like all real science, it gained acceptance when the evidence began to mount up, both from observations and more refined theories.
But Wegener is not a valid argument – just the old “appeal to Galileo” updated a little.
“I must be right because everyone says I’m wrong” is the most asinine argument ever put forward, and consequently I feel I have to quote The Crackpot Index:
Bob (Sphaerica) @123 says
“You’ve chosen in numerous posts to do nothing more than repeat your original point, without elaboration, like a child with his fingers in his ears refusing to listen to something he doesn’t want to hear.”
Numerous? – I have replied twice to specific questions and elaborated my answers. Please go back and check. Take them or leave them. They are my opinions.
[edit – no tit for tat name-calling. Goes for Bob and others too. Stay substantive people.]
This type of paper and continued focus on it are part of the problem, not part of any solution. It is a clear indicator that tribalism, bunker mentality, and “peer” pressure are big factors in climate science. God forbid, you wouldn’t want to be judged as part of the laughable “3% club”, would you? Then you better agree to the basic tenets in full, now raise your right hand…
How can one claim the science is open when this paper is deemed important proof of something somehow?
It is a misrepresentation of the real problem from my point of view.
Agreeing that CO2 warms the atmosphere, and that humans emit a lot of CO2 is not very controversial. Here are a couple questions more relevant, which don’t seem to be covered in these type of polls:
1. Do you believe it been proven to a “very likely” degree that humans are the primary cause for the global warming observed in the last 30 years? (not just some warming, or that CO2 causes some warming, or that some warming has occurred, or that the IPCC says something)
2. Do you believe it has been proven that global climate models are “likely” or “very likely” to be accurate in their predictions that CO2 will generate accelerated warming that may be catastrophic (i.e. large positive CO2 forcings)?
#2 is the one that really matters. It could be rephrased to be more technically correct. The hidden diversionary tactic at play here is that if one believes humans cause some warming, one must then believe that immediate large scale policy action is required, and that is simply not true.
The degree and probability are huge factors, and that uncertainty is what is crippling now, not a perceived army of misinformed deniers. One certainty is that people who peddle in a certain proven oncoming catastrophe (and those who turn a blind eye to them) make easy targets for climate skeptics.
Aircraft are not allowed to take off unless their maintenance/repair paperwork is current and in order. &;>)
Fortunately, the expertise and judgment of trained, tested, and licensed mechanics also is considered in the decision to fly. The legally required M/R and associated documentation is regularly updated by FAA issued Airworthiness Directives, often “prompted by reports” from expert mechanics whose judgment led them to speak up about conditions they considered unsafe. http://www.google.com/#hl=en&source=hp&q=prompted+by+reports+site%3Afaa.gov gets “About 1,490 results”
One reason commercial aviation is safe is that the FAA doesn’t wait to see how good or bad statistically various procedures are, but instead applies expert judgment and the precautionary principle to proactively prevent problems. Unlike those who argue that climate science is so uncertain that we should delay action.
Another reason commercial aviation is safe, and safer than private aviation, is that the (legally required, regularly tested) level of expertise and judgment for pilots and mechanics is high. Like physicians, but unlike politicians with journalism degrees who doubt man is responsible, or doubt that the consequences will be costly, or doubt that the scientific experts actually know their fields, or doubt that the “warmists” concerns are based on facts rather than political opinion.
recaptcha: swami materialism – Is their a special RC database of words to use and AI to make the phrase topical?
Tom Scharf wrote: “Do you believe it has been proven that global climate models are ‘likely’ or ‘very likely’ to be accurate in their predictions that CO2 will generate accelerated warming that may be catastrophic”
CO2 has already generated accelerated warming that may be catastrophic.
Indeed, it is arguably already catastrophic.
Tom Scharf says, “God forbid, you wouldn’t want to be judged as part of the laughable “3% club”, would you?”
Well, that wold depend on whether the 3% were right or the 97% were right, wouldn’t it? I mean what matters, ultimately, is understanding Earth’s climate, right?
You state that it is not controversial that CO2 warms the atmosphere or that humans are responsible for the increased CO2 in the atmosphere. Great, could you maybe work on some of the guys on your side of the argument on that fact. I think Roy Spencer could use some help.
Are you willing to go a step further and acknowledge the very compelling evidence that constrains CO2 sensitivity to be between 2.1 and 4.5 degrees per doubling? If not, than why? After all, how likely do you think it is to get a dozen or so independent lines of evidence all lining up and pointing to a WRONG answer?
On the other hand, if we agree on the favored value of 3 degrees per doubling, then we could easily see 10 degrees of warming this century. Do you not think that this would be a problem? On what basis? Most research on agricultural, climate, health and economic effects of such a rise would strongly disagree with you. Even by 2050, we will have seen 3 or more degrees of warming–and here, too, the peer-reviewed research indicates some severe consequences–drought, more extreme weather, crop failures, more dead spots in the oceans, less phytoplankton…and all as our human population crests at about 10 billion people. You don’t see a threat here?
Of course the proper way to handle any such threat is with probabilistic risk assessment. But the problem is that as yet we cannot bound the risk due to climate change. Until we can do that, PRA counsels risk avoidance. And THAT, Tom, is why action is needed.
Tom Scharf: Do you really imagine that these questions haven’t been asked? They have.
Doran PT, Zimmerman MK (2009)
As for your second question – who do you think is qualified to judge the output of a climate model?
141 (Titus),
Apologies, you are right. I got lost in the large number of people posting replies to you. You had one original post (10), then restated that position 3 times (25, 65, 104), usually to multiple people at once (so do those count as one post each? if so, you total 11 there), and then one more post saying your posts on your position were not numerous (141), yet still not moving the discussion forward.
So your post total is 5, or 13, all to establish that you think that the use of airline mechanics was an inappropriate metaphor, so inappropriate that you can’t bring yourself to read the content of the original post.
In the meantime, have you gone back and actually read the article, so that you can contribute to the discussion of what it actually says?
I will drop this at this point because it is way beyond unproductive, and better qualified minds (“experts?”) are contributing more to the substance of the article than I ever could. It’s better in this case for me to read and learn than to write and be a distraction.
JW 129: Why would anyone even have to invoke freedom of information act to obtain scientific data?
BPL: Short answer: They didn’t.
Long answer: 95% of CRU’s data was already in the public domain. The other 5% was proprietary data of the various national met services, and CRU COULD NOT LEGALLY RELEASE IT. McIntyre got his blog posts to spam CRU with 48 FOI requests over one weekend, when it takes 18 hours to comply with one such request and there are only three people (that’s right, three people!) in CRU.
In short, McIntyre is an antiscience activist, Phil Jones didn’t do anything wrong, and anyone who missed the fact that three investigations have cleared Phil Jones and the CRU isn’t paying attention.
“Science is the belief in the ignorance of experts”
Richard Feynman
TS 142: 1. Do you believe it been proven to a “very likely” degree that humans are the primary cause for the global warming observed in the last 30 years? (not just some warming, or that CO2 causes some warming, or that some warming has occurred, or that the IPCC says something)
BPL: Hell, yes. Don’t you? If not, why not? Want to see the numbers?
TS: 2. Do you believe it has been proven that global climate models are “likely” or “very likely” to be accurate in their predictions that CO2 will generate accelerated warming that may be catastrophic (i.e. large positive CO2 forcings)?
BPL: See above.
TS: #2 is the one that really matters. It could be rephrased to be more technically correct. The hidden diversionary tactic at play here is that if one believes humans cause some warming, one must then believe that immediate large scale policy action is required, and that is simply not true.
BPL: Except that, as a matter of fact, immediate large scale policy action IS required. My own belief is that if we don’t massively switch from fossil fuels to renewables in the next 5 to 10 years, it will be too goddam late.