Ask Me Anything about Climate Science Denial

The good folk at edX (who host our online course Making Sense of Climate Science Denial) generously organised a Reddit AMA (Ask Me Anything) for me this week. The AMA was scheduled to start at 7 am here in Brisbane. When I woke up at 6 am and loaded the AMA webpage on Reddit, 2000 comments had already been posted! So I gulped down a coffee and in the short time available, belted out as many answers as I could as quickly as possible (while linking to relevant videos from our MOOC). Here are a selection of my answers, grouped into categories:

Psychology of climate science denial

Q: What are the main reasons someone would deny climate change?

A: The main driver of climate science denial is political ideology. Some people don't like the solutions to climate change that involve regulation of polluting industries. Not liking the solutions, they deny there's a problem in the first place. A number of empirical studies (including my own PhD research) have found an extremely strong correlation between conservative political ideology and denial of science. And randomised experiments have demonstrated a causal relationship between the two.

This is extremely important to understand. You can't respond to science denial without understanding what's driving it. We examine this in Scott Mandia's lecture

Q: Do you think the psychology behind climate science denial can also explain other types of science denial?

A: A general principle is that people reject scientific evidence that they perceive threatens their worldview. So while different factors drive denial of different areas of science, often you will find the mechanisms are similar. For example, religious ideology drives rejection of evolution science in similar ways to political ideology driving rejection of climate science. Another thing that different types of science denial have in common is they all share the 5 characteristics of denial, as examined in this video from our course:

Q: How can you tell the difference between willful ignorance (or maybe not ignorance but disagreement) based on an agenda, and legitimate disagreement based on really misunderstanding data, or surface level policy disagreement?

A: This is an excellent question and I address it in my lecture on the 5 characteristics of denial:

It's very difficult to tell the difference between intentional deception (disinformation) and genuinely held misunderstandings (misinformation). My lecture explains how the characteristics of denial - cherry picking, logical fallacies, conspiracy theories - can arise from psychological bias. So intentional deception looks much the same as when someone is deceiving themselves through psychological bias. 

Q: Can you talk a little about confirmation bias, cognitive dissonance, the backfire effect, and how to overcome people's deeply held beliefs?

A: Science denial is confirmation bias on steroids. When we receive scientific evidence that we perceive threatens our worldview, we experience cognitive dissonance - the sensation of two conflicting thoughts/feelings. Do we abandon our worldview that we've held all our lives and that comprises our identity and binds us to our community, or do we reject that scientific evidence we just encountered. Seems a pretty clear choice, right? That's what's going on under the hood when people deny scientific evidence. It can even cause people to reinforce their beliefs, bolster their pre-existing attitudes - in response to conflicting evidence. This is the worldview backfire effect.

There is research indicating that if scientific evidence is presented in worldview friendly ways, from messengers who share the values of the recipient, then the scientific evidence at least has a fighting chance. But I believe our efforts are better spent on the much larger majority who are open to scientific evidence, rather than banging our heads against a brick wall trying to persuade the unpersuadable.

Q: Why do lukewarmers seem to always side with outright deniers? Shouldn't people like Curry, Pielke Sr. and others spend just as much time (if not more) criticizing those who claim AGW isn't happening, or is a hoax? Doesn't that simple fact invalidate their position?

A: There are three stages of climate science denial: denial of the existence of global warming, denial of the causation of global warming and denial of the research into climate impacts. "Lukewarmers" fall into the latter category. So when lukewarmers say "I don't deny the science", they may accept that humans are causing global warming but they are still rejecting inconvenient scientific evidence. Denial of scientific research into climate impacts is still climate science denial.

What all three types of climate science denial have in common is they all lead to the same conclusion - arguing against climate action. This is why those in denial about climate impacts rarely criticise those who deny global warming - they both have the same end goal in mind.

Scientific Consensus

Q: Do you honestly believe that science should just be done by consensus?

A: I believe our scientific understanding should be guided by the full body of evidence. If you're interested in my full views on the roles of evidence and consensus, I recommend watching the first three lectures of our course:

Or better yet, enrol at where not only can you view the videos, you can also engage with our interactive activities and discussion forums.

Q: Do you adhere to Karl Popper's philosophy that in order to make a valid scientific statement, it needs to be possible to disprove the statement. If so, what type of data or piece of evidence would turn you into a climate skeptic?

A: Science does need to be disprovable, that's what distinguishes it from pseudoscience. What would turn me into a climate skeptic? I already am a climate skeptic because skepticism is a good thing - skeptics consider the body of evidence before coming to a conclusion (sorry, I know that's just semantics but it's an important point). But what would convince me to reject human-caused global warming? The answer is simple - provide an alternative explanation that both fits all the human fingerprints listed above and rules out greenhouse warming.

Q: With regard to your infamous 97% study... why were you so resistant to releasing your data for review?

A: On the day our 97% consensus paper came out, we also released data of the final ratings given to every paper in our analysis. But most importantly, we also created an interactive webpage that allowed the public to replicate our analysis. We were keen for people to go through the same process we went through - read all the climate abstracts and experience the breadth and depth of scientific research into climate change. So I find it extraordinary that people complain about our data release when we actively encouraged people to replicate our results. The interactive rating page is at

However, as researchers, we also have ethical obligations to protect the confidentiality of participants in our research. Consequently, we did not and will not release data that violates the privacy of participants. This data isn't required whatsoever to replicate our research.

So again, I strongly encourage everyone to visit and try to replicate our rating process. Compare your ratings to ours. Read the climate research. Or even better, attempt to conduct your own independent analysis, quantifying the degree of scientific agreement on human-caused global warming. It's significant that amongst all the critics of our consensus research, and there are many, not one has published an independent analysis quantifying the level of consensus.

Q: Are there any scientific studies or strong arguments that you consider legitimate critisism on the current consensus in the scientific community on anthropogenic global warming?

A: I'm not aware of any legitimate criticism of the consensus that humans are causing global warming. To legitimately cast doubt on human-caused global warming would require doing away with the many human fingerprints being observed in our climate today - less heat escaping to space, more heat returning to earth, shrinking daily cycle, shrinking yearly cycle, cooling upper atmosphere, etc.

Q: What do you think is the best argument climate change deniers make?

A: The one advantage that climate science denial has is all that needs to be done to delay action on climate change is to foster doubt and confusion. To achieve this, they don't have to provide an alternative, coherent position - they just have to cast doubt on the overwhelming body of evidence that humans are causing global warming. So there is no single, best argument against climate science - just an incoherent soup of noise that nevertheless is effective in confusing the public and delaying support for action to mitigate the worst impacts of climate change.

How to respond to science denial

Q: Tell us about the relationship between acceptance of the science and acceptance of policies to respond to the problem described by science... And what's the relationship generally between scientific and policy beliefs? Can one influence the other? Does the causality run both ways?

That's a great question. Psychological research has found a strong link between acceptance of science and acceptance of policies. In particular, the work of Ed Maibach at George Mason University has found that public perception of scientific agreement is a "gateway belief" that has a flow-on effect, influencing a range of climate beliefs and attitudes including acceptance of climate policies. Maibach found that informing people about the 97% scientific consensus has the effect of increasing people's support for climate policies. Maibach found that consensus messaging is even effective among political conservatives. This underscores the importance of communicating the scientific consensus and closing the consensus gap.

Q: ...I'd also like to know what your perspective is on the feasability of reversing climate change or bringing it to a halt? In other words, do your findings on the psychology behind climate skepticism provide any leads on how to remove this attitude from the population?

A: How to respond to climate science denial and turn this situation around? I'm doing a PhD on this very question and I believe the answer is inoculation - we need to inoculate the public against the misinformation that originates from science denial. We will delve into how to do this in week 6 of our course but I touch on this briefly in a recent Conversation article:

Q: You mention that you're looking into "inoculation against misinformation." What are some ways to encourage skepticism?

A: In my own research, I've found that explaining the techniques used to distort science is quite powerful in inoculating against misinformation - it completely neutralises misinformation. So that is the approach we take with our course - we debunk all the most common climate myths by explaining the techniques and fallacies used to distort the science.

Q: Don't you feel there's a danger in talking about the motivations of people who deny climate science, that discussion of motivations can be used to try to shame people into changing their beliefs rather than to persuade them with arguments?

A: Really incisive question, thanks! The challenge here is that the scientific evidence tells us that persuading people who are in denial with scientific arguments is futile or counter-productive. This finding underscores this important principle: scientists and science communicators need to take an evidence-based approach to science communication and that means heeding the scientific research into how people process evidence. And this social science research tells us that motivated reasoning has a strong influence on how people process evidence.

I think understanding motivated reasoning is also important because it helps people understand that people who use the techniques of denial aren't necessarily trying to intentionally deceive people. They can be genuinely held beliefs arising from cognitive biases. It's really important that people understand this - I explain it in my video lecture on the characteristics of denial:

Q: Is there any meaningful action I can take as an individual? Or, should I just start stashing guns, drugs, canned goods, and water filters in a nearby Appalachian cave?

A: Please don't hole up in a cave - we need you. There are two things an individual can do - walk the walk and talk the talk. Walk the walk means being more energy efficient and reduce your own individual footprint. Talk the talk means communicate the realities of climate change and the need for action to your friends, family and most importantly, your elected officials. When enough people speak up to politicians, the politicians will realise that the one thing they care about - their job - is at stake and will act accordingly.

Q: What if in the next few years Climate Change Deniers fizzle away (doubtful, I know)? ... What would you turn your research, your time, your attention to next?

A: Let's say hypothetically that we are successful in reducing the influence of climate science denial to the point where it has no significant effect on society. What next? Well, I must confess I have given this some thought and I would probably turn my attention to other forms of science denial. Evolution denial is something I'm quite interested in but a form of denial that is of more societal consequence is vaccination denial. Preventable diseases are making a comeback because of this form of science denial and it's completely unnecessary.

Q: How do you feel about Climate Change Denialists adopting the name "Skeptic"?

A: I think it is extremely unfortunate that the characteristics of science denial - cherry picking, conspiracy theories, logical fallacies - have come to be associated with the good name of skepticism. I've written an article on this very topic, published last week in Skeptical Inquirer:

These are just the tip of the iceberg - only part of my answers and a very small fraction of the total number of comments on the AMA page (currently there are 2,487 comments). If you have a few spare hours to kill, go check out the full AMA page on Reddit.

No, wait, if you have a few spare hours, enrol in the Making Sense of Climate Science Denial MOOC!

Posted by John Cook on Thursday, 7 May, 2015

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