There is this statement in the introduction of the Cook et al 2018 paper that caught my eye:
This paper introduces key critical thinking concepts and outlines a straightforward process for identifying reasoning errors that allows for people who lack expertise in climate science to confidently reject certain denialist arguments.
In a way, I can understand what they are trying to do. Just before I started blogging, now five years ago, I had the idea to look somewhat deeper into logical fallacies. At that time I wasn’t familiar with the global warming debate and it was my hope that I could find a fast and easy way to differentiate between right arguments and wrong arguments, without having to put much effort in studying the topic. However, it didn’t take very long before I realized that for some type of fallacies this would be perfectly possible, but not for most. If I wanted to know right from wrong, then I had to dive in the arguments themselves.
So although I think that their effort is praiseworthy, in practice it is not black & white. My conclusion back then was that when one wants to confidently confirm or reject an argument, then one needs to get messy and go to the source and understand what the argument is all about. I would certainly not put my bet on the knowledge of logical fallacies alone. Without some background, it could lead to possible misinterpretations.
This became rather clear in the page on the SkepticalScience website that was devoted to the Cook et al paper. The post is titled Humans need to become smarter thinkers to beat climate denial and John Cook is a co-author. At the beginning of the post, they basically repeat the statement from the paper in a slightly different wording:
The new paper published today suggests an even more proactive approach to defeating myths. If people can learn to implement a simple six-step critical thinking process, they’ll be able to evaluate whether climate-related claims are valid.
Again, it seems deceptively simple. Just learn how to implement a simple thinking process and you will able to evaluate whether some claim is valid or not.
This is the first step in the process:
Step 1: Identify the claim being made. For example, the most popular contrarian argument: “Earth’s climate has changed naturally in the past, so current climate change is natural.”
When I follow that link, I get a list of “contrarian” arguments and when I then sort those arguments by popularity, the argument “Climate’s changed before” is indeed first on the list, so the most “popular” among “denialists”. That this example was chosen for the video abstract is therefor not exactly surprising.
However, previous experiences with the examples given by the SkepticalScience team let me wonder how representative this example argument is for what they want to prove in that post? They describe the claim as “Earth’s climate has changed naturally in the past, so current climate change is natural”, but I don’t see it coming back in the description of the myth. Clicking on the link of that most popular argument brings me to the Climate’s changed before myth page and the title “What does past climate change tell us about global warming?”. This is how the myth is summarized:
Climate’s changed before
Climate is always changing. We have had ice ages and warmer periods when alligators were found in Spitzbergen. Ice ages have occurred in a hundred thousand year cycle for the last 700 thousand years, and there have been previous periods that appear to have been warmer than the present despite CO2 levels being lower than they are now. More recently, we have had the medieval warm period and the little ice age. (Richard Lindzen)
There are two surprises here. Firstly, this summary perfectly explains the “climate change before” claim, but I miss the second part: “so current climate change is natural”. Secondly, I was surprised to see the name of Richard Lindzen. As far as I know, Lindzen agrees that CO2 is a greenhouse gas and that it is expected to lead to increasing temperatures when we put more of it in the atmosphere. So I would be really surprised that he, of all people, would have claimed that current climate change is natural just because it has changed in the past too.
I then went to the webpage where Lindzen made that claim and it didn’t take long before I found that part that was showed in the summary. However, reading until the end, I couldn’t find the claim that current climate change is natural because the climate has changed before. There was even this (my emphasis):
Supporting the notion that man has not been the cause of this unexceptional change in temperature is the fact that there is a distinct signature to greenhouse warming: surface warming should be accompanied by warming in the tropics around an altitude of about 9km that is about 2.5 times greater than at the surface. Measurements show that warming at these levels is only about 3/4 of what is seen at the surface, implying that only about a third of the surface warming is associated with the greenhouse effect, and, quite possibly, not all of even this really small warming is due to man (Lindzen, 2007, Douglass et al, 2007).
So, yes, he certainly entertains the idea that the change is natural, but not because the climate changed before, but because the hallmarks are not there. He even acknowledges that human emissions could have an influence, albeit small (which was what I expected he would say).
Again, this is a perfect explanation of the claim that the “climate changed before”, but without the “so current climate change is natural” part. Why is that important? Remember, according to the video abstract and the SkepticalScience post, the misinformation of that “denialist” claim rests on a hidden premise. This is the structure:
- Premise 1: climate has changed naturally in the past
- Premise 2: the climate is changing now
- Hidden premise: “if something wasn’t a cause in the past, it can’t be a cause now” (in the video abstract) or slightly differently worded as “if nature caused climate change in the past, it must always be the cause of climate change” (in the SkepticalScience post)”
- Conclusion: current climate change is natural
This hidden premise is crucial to complete this fallacy. It is central to the invalidation of that specific argument and is nowhere to be found in the Lindzen article. Therefor it is a bad example for the claim that the most popular “denialist” claim is that “Earth’s climate has changed naturally in the past, so current climate change is natural“. Lindzen had numerous reasons why current climate change is (mostly) natural and that climate changed in the past (therefor that must also be the case now) was not one of them. The “climate is always changing” claim in the article seem to be a reaction to the assumption that the climate was stable until humans started to emit CO2 and it was not used as a reason for why that change is (mostly) natural.
This is the pitfall of this easy six-step critical thinking for people who lack expertise. It rests on a specific line of reasoning that is not that easy to spot when one only looks at some key words (in this case “the climate is changing”). If even John Cook, as an author of the paper AND the SkepticalScience post, is glossing over the specifics of misinformation in his own example, then how on earth would those who lack expertise be able to spot the difference?