Oreskes 2004 and Peiser

As mentioned in previous post on the consensus article in skepticalscience, there was an entry explaining the Oreskes 2004 paper. In the article, it was presented as “Oreskes 2004 and Peiser”. Which was an odd thing. Peiser didn’t write the paper together with Oreskes (otherwise it would be “Oreskes and Peiser, 2004). At the contrary, Peiser wrote a critique on the conclusion of the paper (that not a single paper rejected the consensus position). The author of this article seems to have a lot of confidence also mentioning the critique together with the Oreskes paper.

At that time, I did not know much about the Peiser critique and initially had to rely on the explanation provided by the author of the skepticalscience article. This is how the critique is presented in the article:

Oreskes 2004 and Peiser

A survey of all peer-reviewed abstracts on the subject ‘global climate change’ published between 1993 and 2003 shows that not a single paper rejected the consensus position that global warming is man caused (Oreskes 2004). 75% of the papers agreed with the consensus position while 25% made no comment either way (focused on methods or paleoclimate analysis).

Benny Peiser, a climate contrarian, repeated Oreskes’ survey and claimed to have found 34 peer reviewed studies rejecting the consensus. However, an inspection of each of the 34 studies reveals most of them don’t reject the consensus at all. The remaining articles in Peiser’s list are editorials or letters, not peer-reviewed studies. Peiser has since retracted his criticism of Oreskes survey:

“Only [a] few abstracts explicitly reject or doubt the AGW (anthropogenic global warming) consensus which is why I have publicly withdrawn this point of my critique. [snip] I do not think anyone is questioning that we are in a period of global warming. Neither do I doubt that the overwhelming majority of climatologists is agreed that the current warming period is mostly due to human impact.”

A [snip] in a skepticalscience article? I need to know more about that! What exactly got snipped in that quote from Peiser?

I also noticed some discrepancy between the description by the author of the skepticalscience article and the quote from Peiser. The author of the skepticalscience article claims that Peiser retracted his criticism of the Oreskes survey, while the quote (attributed to Peiser) mentioned that he withdrew this point of his critique.

So, what did Peiser actually withdraw? His complete critique on the paper (as suggested by the skepticalscience author) or just part of it (as suggested by the quote attributed to Peiser)? In the last case, which part exactly did he withdraw?

As it is explained in the article, I understood that Benny Peiser replicated the study and found 34 peer reviewed studies rejecting the consensus. It seems that later was found (by whom?) that most of those 34 papers didn’t reject the consensus and Peiser retracted (part of) his critique. Connecting both parts of the quote before and after the snip seems to suggest that Peiser, after the correction, changed his mind and is now fully in line with the Oreskes 2004 paper. Which seems to contradict Peiser’s quote that he only withdrew part of his critique.

Time to follow the links and find the source to see what was actaully said and what was omitted. A link is provided, but curiously, it goes to an episode of an ABC program called “MediaWatch” and the Peiser critique is not even the subject of this episode. Its subject is an article written by Andrew Bolt in the Herald Sun in which the conclusion of the Peiser critique was mentioned. Luckily, the MediaWatch episode also has some links that went to the orginial source.

Following the first link brought me to the retraction email from Peiser to Science Magazine. In it, Peiser wrote that he tried to replicate the Oreskes findings and that his results didn’t confirm her result. It was an interesting read. Peiser’s argumentation is much more comprehensive than is explained in the skepticalscience article:

• he found 34 abstracts contradicting the claim that the universal agreement had not been questioned even once in the peer-reviewed literature since 1993
• he found 44 abstracts that emphasise the claim that current climate change is natural
• he only found 13 abstracts that explicitly endorse the “consensus view”
• a significant number of abstracts reject what Oreskes calls the “consensus view”
• natural climate variability over recent geological time is greater than reasonable estimates of potential human-induced greenhouse gas changes.
• he agrees that a majority of publications goes along with the notion of anthropogenic global warming by applying models based on its basic assumptions
• there are skeptical scientist out there who write papers. Peiser admits that these are a minority, but critical papers should be found in the ISI database and the result that “not a single paper rejected the consensus position” is dubious.

He also explains that he found discrepancies when he compared his results with the result claimed by Oreskes. He found much more abstracts than Oreskes and was puzzled by this fact. It made him believe that Oreskes could not have done the specific search she claimed to have done in the paper.

Apparently, she didn’t. That became clear when I followed the second link, pointing to an inquiry in which Peiser answers the questions of someone from ABC (probably in function of that episode of MediaWatch?). The search term she used was indeed “global climate change” but she limited her search to documents of the type “article”, while Peiser searched for the same term, but for all document (it was not mentioned in the paper that only articles were selected). That shed some light on the controversy. There was also this interesting question:

It implies that, given this methodology, the 34 articles you found that “reject or doubt the view that human activities are the main drivers of the observed warming over the last 50 years” may not have been included in the 928 articles randomly selected by Prof Oreskes. Is this possible?

The question is whether (most of) the 34 abstracts that Peiser found were of a different document type than “article”. Interestingly, in answering this question, Peiser explains what exactly he withdrew:

Yes, that is indeed the case. I only found out after Oreskes confirmed that she had used a different search strategy (see above). Which is why I no longer maintain this particular criticism. In addition, some of the abstracts that I included in the 34 “reject or doubt” category are very ambiguous and should not have been included.

This answer clarifies a lot. Peiser found more abstracts than Oreskes because in his search strategy more document types were selected, therefor coming to more abstracts than Oreskes did. The 34 abstracts found by Peiser apparently were not (all?/most?) included in the 928 articles selected by Oreskes. After he came to know the exact methodology, he withdrew that specific part of his criticism. Which is different from the suggestion by the author of the skepticalscience article that he retracted all the points of critique on the survey. As far as I could find, Peiser still had points of critique on the paper as he also explains in the same inquiry email:

Please note that the whole ISI data set includes just 13 abstracts (less than 2%) that *explicitly* endorse what she has called the ‘consensus view.’ The vast majority of abstracts do not deal with or mention anthropogenic global warming whatsoever. I also maintain that she ignored a few abstracts that explicitly reject what she calls the consensus view.

Peiser also put the abstracts online so everybody could check (there seems to be a problem with that server, but the abstracts can still be found via the Wayback Machine).

That is why the author of the skepticalscience article was so confident in mentioning the critique together with the survey. Readers are tricked into believing that this clarification by Oreskes settled all criticism and that there was no critique on the survey anymore. By omitting that part of the story, the author of the skepticalscience article made it very safe to mention the critique.

Did the author knew the full extent of the critique of Peiser? I have serious doubts that he actually went to the source and read the whole story himself. Remember, the reason for my search was the snip that I found in the quote. When I read the MediaWatch inquiry email, I found the second part of the quote in the inquiry email, but couldn’t find the first part in the rest of the text. I was puzzled and started to doubt whether this was the original source after all, but when I went back to the MediaWatch episode, I found that first part! It is introduced as a quote from the first email written by Peiser to ABC (there was no link to it, so I don’t know the context or the rest of the content). And yes, further in the episode, I found that second part of the quote…

It all fitted together, this seems to be were the author of the skepticalscience article got his quote from. Chances are that the author just copied the quotes from the MediaWatch episode on Andrew Bolt and snipped the text in between both quotes since it was not related to his article. So, he quoted secondhand information from a source in which the Peiser critique was mentioned, instead of going to the original source just one click further…

Another thing that points in that direction is that the author of the skepticalscience article reported that Peiser “claimed to have found 34 peer reviewed studies rejecting the consensus”. This is not the case and if he actually viewed the source, then he would have known that. Peiser only mentioned that he found 34 abstracts rejecting the consensus, he didn’t claim that he found 34 “peer reviewed studies” rejecting the consensus. Also Oreskes didn’t claim that she found peer-reviewed studies. Although she mentioned “peer-reviewed literature” a couple times in the paper, she also used the term “abstracts” to describe what she found. So the claim that Peiser found 34 “peer-reviewed studies” came from the imagination of the author of the skepticalscience article himself.

By the way, that second part of the quote after the snip was not a new insight of Peiser after he realized that Oreskes used a different search strategy, as seems to be suggested in the article. He made a similar claim in the original critique.

How relevant is all this? Personally, I find the Oreskes findings rather meaningless. In previous post, I wrote about the term “equivocation” (the use of ambiguous terms) and said that the Oreskes survey makes a good example. Oreskes didn’t define what she meant by “climate change” and “anthropogenic climate change”, therefor it could be interpreted in different ways, depending on the definition used by the reader. In the skepticalscience article, this ambiguity is used to declare a much broader consensus than actually exists.

Concluding, the framing is very strong in this tiny part of the skepticalscience article. The author of the skepticalscience article forgot/glossed over/didn’t understand/omitted essential information that would make the reader understand the actual critique of Peiser. The combining of the two separate quotes made me wonder whether the author understood the critique of Peiser and whether he just relied on the information provided in the MediaWatch episode instead of going to the original source.

Post Scriptum 1
I explained that the author of the article used “peer-reviewed studies” instead of “abstracts” as is done in the Oreskes 2004 and the Peiser critique. That seems like something insignificant, but I think it is important. First, because it shows that the author probably didn’t read the critique (well) and filled in that gap with what seems logical to him. Second and more importantly, the essence of Peiser’s specific retraction was that he used a different search strategy, therefor obtaining more abstracts than Oreskes. Of those 34 abstracts that rejected the consensus found by Peiser, most were not covered by the selection of Oreskes. Then claiming that Peiser found 34 “peer-reviewed studies” is misleading since it will suggest that those 34 abstracts were in the Oreskes’ selection and therefor wrongly concluding that Peiser retracted “his critique” because those “peer-reviewed studies” were just miscategorized as being rejecting the consensus. It seems that is what happened in the MediaWatch episode and this was then incorporated into the skepticalscience article.

Post Scriptum 2
This is a graphical representation of how the quote is constructed:

This is how it is constructed:

• At the top, there is a quote from the first email from Peiser to MediaWatch
• In the middle, there is part of the main story of the MediaWatch episode and not relevant to the skepticalscience article, therefor snipped
• At the bottom, there is a quote from the answer to the inquiry email from MediaWatch.

This makes me think that this is the place where the quote was copied/constucted from.

Together it suggests that Peiser had to admit that only a few abstracts explicitly rejected the consensus (first part) and that, after he realized this, he now agrees with Oreskes 2004 (second part). Therefor omitting the different search stategy of Peiser compared to Oreskes and ignoring that the second part was not new since it was also present in his critique. Also omitting that there were other points of critique that still stand.

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