The subject of the second episode of the evidencesquared podcast mentioned in the previous post is among other “Scott Pruitt’s denial of the scientific consensus on human-caused global warming, both in a CNBC interview and in his hearing for head of the EPA”. At 03:57 in the podcast, the presenters start a audio excerpt of an interview of Scott Pruitt at CNBC back in 2017 when he was the head of the EPA (the interview at CNBC can be viewed here):
Do you believe that it has been proven that CO2 is the primary control knob for climate? Do you believe that?
No, I think that measuring with precision human activity on the climate is something very challenging to do. There is a tremendous disagreement about the degree of impact. So, no, I would not agree that it is a primary contributor to the global warming that we see.
We don’t know that yet. As far as, we need to continue the review and the analysis.
The most surprising find in the evidencesquared episode 2 podcast (see previous post) is a statement by John Cook about the endorsement levels of the Cook 2013 paper. This is how he reacts to his observation that some skeptics claim that they belong to the 97% because they believe that the world is warming and humans have some influence (my emphasis):
Yeah, and the way that the consensus position is often expressed by people who don’t accept the consensus: “Well, I am part of the 97%, because I think that humans are causing some of global warming, but I don’t think it is most and therefor that makes me part of the 97%”.
Right, we saw that with criticism from publishing of the Wall Street Journal, for example.
Yeah, we come to that in a moment, but the problem with that argument is, in our 2013 study, we explicitly ruled that out as an option. Whenever there was an expression that humans are causing less than half of global warming, we categorized that as rejection of the consensus. So the person who thought that humans are causing some, just not more than half, that is a rejection of the consensus.
I remembered from reading the Cook 2013 paper that there were only two levels of endorsement that quantified the consensus and the papers in those two levels just amounted to less than 1% of all papers in their data set. How on Earth could he now claim that they considered it rejecting the consensus when a paper expressed that “humans are causing less than half of global warming” when almost all data had no clear quantification?
Remember one of previous posts about a video explaining the Cook 2016 paper, in which Bernie Sanders extended the consensus position well beyond what was found in the paper? In the meanwhile, I came to know that Cook apparently criticized Sanders because of such overreaching statement(s). That immediately drew my attention. I wondered in what form this “criticizing” was done, so I found myself searching for that critique.
It wasn’t that simple though, but after a long search, I found that Sanders’ statement was criticized in a podcast from the evidencesquared site, more specifically “episode 2”.
Recently, I came across The Consensus Handbook by Cook, van der Linden, Maibach and Lewandowsky. It was already the first text that I encountered (the take-away message on the introduction on page 3) that caught my attention (my emphasis):
Based on the evidence, 97% of climate scientists have concluded that human-caused climate change is happening. This scientific consensus has been a hot topic in recent years. It’s been referenced by presidents, prime ministers, senators, congressmen, and in numerous television shows and newspaper articles.
That last sentence reminded me of a video in which lead author John Cook explained his 2016 paper (Consensus on Consensus). It was the introduction in the video that puzzled me until now:
It has been a long time that I read something of John Cook. I recently came across the National Center for Science Education blog post in which he was interviewed. The post is titled Got Climate Change Misconceptions? John Cook Can Help and dates from the beginning of this year. This “help” seems to be learning students how to combat climate change misconceptions.
I am not going to make a long post, so I will come to the point immediately. This is what caught my eye at first read (my emphasis):
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?
As a non-native English speaker, I often encounter new words. One such word is “equivocation” (using the same word for different things or the use of such word in multiple senses throughout an argument, leading to a false conclusion). The first time I heard about it, I recognized it as something that is frequently used in global warming/climate change communication.
At the end of last week, when searching for something related to the consensus, I landed at the Skeptical Science page titled The 97% consensus on global warming (intermediate version). I am pretty sure that I must have read this before, but having “equivocation” at the back of my mind, gave it a new dimension.
As the title suggests, its subject is the 97% consensus. It starts from the statement of the Petition Project that “there is no convincing scientific evidence that human release of carbon dioxide will, in the foreseeable future, cause catastrophic heating of the Earth’s atmosphere”.
The Skeptical Science author calls this a myth and tackles it by explaining that a consensus of around 95% is found in papers like Cook et al 2013 & 2016, Oreskes 2004, Doran 2009 and Anderegg 2010. Also mentioned are the Vision Prize poll that basically found something similar and a list of scientific organizations that endorse the consensus.
I don’t know much about the Petition Project, but from the excerpt given in the Skeptical Science article, it is clear that the Petition Project statement is very specific. They claim that there is no consensus specifically on the catastrophic nature of global warming caused by human emissions.