Posts Tagged ‘Climate change’

Picture credit: NOAA.

Picture credit: NOAA.

Note: I have joined the “virtual class” component of Dan Kahan‘s Science of Science Communication course at Yale University. As part of this I am endeavoring to write a response paper in reaction to each week’s set of readings. I will post these responses here on my blog – my paper for week 11 is below. Previous responses are here. I will also be participating in the discussion on Kahan’s own blog.

This week’s focus:

What is/should be the goal of climate science education at the high school or college level? Should it include “belief in” human caused climate change in addition to comprehension of the best available scientific evidence?

I started off thinking I had not changed my mind since writing my evolution education post two weeks ago. I planned to contend that, as with evolution, there is a reason that we are not satisfied for students to simply acquire knowledge about climate change. If they were to cogently describe what the theory of anthropogenic global warming (AGW) entails, but flat-out deny the truth of the theory, that would leave us unsatisfied – not just because global warming is a pressing issue which requires political will and thus voter backing to tackle (though that’s certainly true) but because we’d be left with the feeling that on some level the student still doesn’t “get it.”

Unpacking my argument from last week – which proposed that we should aim for students to believe the following…

(proposition p) Evolution, which says x, is the best supported scientific way of understanding the origins of various species, the way species adapt to their environment, etc etc.

… I can identify three reasons for this to be our aim:

  • First, because science *is* the best scientific explanation for these phenomena, and thus by knowing this, students know a true fact about the world;
  • Second, because armed with that knowledge, they are better equipped to apply the theory of evolution to scientific and other real-world problems; and
  • Third, (as I outlined in my comment to Cortlandt on the next post) because we wish students to understand the scientific justification for the theory of evolution, and if they understand that, then belief in proposition (p) necessarily follows. (It occurs to me now, however, that this is not the most terrific argument, because necessity does not flow in the other direction. Believing that p does not necessarily mean the student understands the scientific justification for evolutionary theory; he could take (p) on faith.)

The consensus problem

The climate equivalent of proposition (p) might be something like:

(q) The theory of anthropogenic climate change is the best scientific explanation we have for observed increases in the mean global temperature, and the theory predicts that if man continues to produce greenhouse gases at a similar rate, the temperature will continue to rise.

Proposition (p) could have included a stipulation about predictive power – indeed, to be a valid scientific theory, the theory of evolution must have predictive power. But while I didn’t think that needed to be spelled out for (p), I have done so for (q), because climate change is a subject whose vital importance – and whose controversy – truly rests on its predictions.

But there’s a problem here, and maybe a mismatch. In proposing that we aim for student belief in proposition (p), I figured we were disentangling identity from knowledge. Any student, taught well enough, could come to see that proposition (p) is true – and still choose not to believe in evolution, because their identity causes them to choose religious explanations over scientific ones.

For climate change, however, we may not get that far. There seems to be mixed evidence for the effectiveness of communicating scientific consensus on AGW.

As previously discussed, Lewandowsky et al found that subjects told about the 97 percent scientific consensus expressed a higher certainty that CO2 emissions cause climate change. Dan Kahan counters that this finding seems to bear little external validity, since these are not the results we’ve seen in the real world. From 2003 to 2013, the proportion of the US public who said human activities were the main cause of global warming declined from 61 to 57 percent.

In Cultural Cognition of Scientific Consensus, Kahan finds that ideology, ie “who people are,” drives perceptions of the climate change consensus. While 68% of egalitarian communitarians in the study said that most expert scientists agree that global warming is man-made, only 12% of hierarchical individualists said so.


From Kahan, Jenkins-Smith and Braman, Cultural Cognition of Scientific Consensus. Journal of Risk Research, Vol. 14, pp. 147-74, 2011.


On the other hand, as Kahan said in a lecture at the University of Colorado last week (which I live-streamed here – unfortunately I don’t think they’ve posted the recording), most people who dismiss AGW nonetheless recognize that there is a scientific consensus on the issue. At least on the surface this seems at odds with Kahan’s previous findings, so I’d like to look further into these results. (I think the difference may come down to what Kahan describes, in Climate-Science Communication and the Measurement Problem, as the difference between questions that genuinely ask about what people know and those that trigger people to answer in a way that aligns with their identity. Why one of Kahan’s consensus questions fell in the former camp and one in the latter, I do not yet know.)

How is it possible that someone can recognize the scientific consensus on AGW, but still dismiss the truth of AGW? The most natural answer is that such people can readily dismiss the scientific consensus, perhaps arguing the scientists are biased and untrustworthy. This, by the way, points strongly that we should have always expected consensus messaging to fail!


So, if the aim is not consensus…?

Returning to education, I think this warning about consensus messaging points to the importance of creating a personal understanding of the science – i.e., exposing students to the reasoning and evidence behind climate change theory, and walking them through some of the discovery processes that scientists themselves have used. There may be serious limits to what this can achieve, because smart students may perceive that the arguments being used in the classroom have been developed by the scientists that they distrust. But undecided students may be persuaded by the fundamental soundness of the scientific arguments.

There is another danger: conservative students (especially the smart ones) may also reject the scientific arguments advanced in class because they will perceive that at a certain point they must taking things on authority; that the processes involved are too complex and the amount of data too large for a non-specialist to come to a solid independent judgment on. Furthermore, the students can entertain the idea that there is a viable alternative scientific theory because there are many prominent voices that back up this view.


Back to evolution

Again looking back at last week, I realize now that the same problem exists for evolution. The genius of “intelligent design” and “creation science” is that they allow an exit from the scientific-religious conflict in what many of us would call the wrong direction. Students can use this “out” to accept the science they like, reject that they don’t, and view it all as a “scientific theory.” Rather than accept (p) and then be forced to either choose religion over science, or somehow partition these parts of themselves (which Hermann, as well as Everhart, indicate is how many people cope), students may use religion *as* science and reject (p) altogether.

So now I’m beginning to doubt whether my aim in that essay really was achievable. It’s probably still a good idea to aim for beliefs of type (p), because this is a means of encouraging scientific literacy and nature of science understanding. But religious students with a good grasp of the nature of science will probably still find that “out” and will not agree with the evolution proposition. And other, less scientifically oriented students will simply say, “OK, this is the best science, but I trust religion over science.”


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Note: I have joined the “virtual class” component of Dan Kahan‘s Science of Science Communication course at Yale University. As part of this I am endeavoring to write a response paper in reaction to each week’s set of readings. I will post these responses here on my blog – my paper for week seven is below. Previous responses are here.

I will also be participating in the discussion on Kahan’s own blog.

Here was our assignment for week 7:

Imagine you were

  1. President Obama about to make a speech to the Nation in support of your proposal for a carbon tax;
  2. a zoning board member in Ft. Lauderdale, Florida, preparing to give a presentation at an open meeting (at which members of the public would be briefed and then allowed to give comments) defending a proposed set of guidelines on climate-impact “vulnerability reduction measures for all new construction, redevelopment and infrastructure such as additional hardening, higher floor elevations or incorporation of natural infrastructure for increased resilience”;
  3. a climate scientist invited to give a lecture on climate change to the local chapter of the Kiwanis in Springfield, Tennessee; or
  4. a “communications consultant” hired by a billionaire, to create a television advertisement, to be run during the Superbowl, that will promote constructive public engagement with the science on and issues posed by climate change.

Would the CRED manual be useful to you? Would the studies conducted by Feygina, et al., Meyers et al., or Kahan et al. be? How would you advise any one of these actors to proceed?

The readings 

First, some thoughts on these four readings.

The CRED Manual: well-intentioned, but flawed2015-02-27_10-42-04

Source material: Center for Research on Environmental Decisions, Columbia University. “The Psychology of Climate Change Communication: A guide for scientists, journalists, educators, political aides, and the interested public.”

When I first read the CRED manual, it chimed well with my sensibilities. My initial reaction was that this was a valuable, well-prepared document. But on closer inspection, I have misgivings. I think a lot of that “chiming” comes from the manual’s references to well-known psychological phenomena that science communicators and the media have tossed around as potential culprits for climate change denialism. But for a lot of these psychological processes, there isn’t much empirical basis showing their relevance to climate change communication.

Of course, the CRED staff undoubtedly know the literature better than I do, so they could well know empirical support that I’m not aware of. But the manual authors often don’t support their contentions with research citations. That’s a shame because much of the advice given is too surface-level for communications practitioners to directly apply to their work, and the missing citations would have helped practitioners to look more deeply into and understand particular tactics.

Let’s not talk about it

In particular I would put to one side much of the CRED recommendations to do with: 

Framing: Some of these seem like assumptions. “College students are concerned with green jobs” – how do we know? In addition, Myers’ work (see below) suggests that the suggestion of a “national security” frame is ill-advised – as is this:

“Communicators may find it useful to prepare numerous frames ahead of time, including climate change as a religious, youth, or economic issue.”

The method should not be to try whatever framing seems plausible and see what sticks – unless we’re doing that as part of a controlled field experiment.

Correcting misconceptions. The CRED manual says communicators should discover what misconceptions their audience has about climate change, and “replace” them “with new facts.” Is this doable? How would one replace erroneous information with new facts? The reasoning here sounds a little too close to the discredited information deficit model.

The authors go on to cite an example from some of their own research, concluding that communicators should try to correct misapprehensions because they lead the public to support inappropriate solutions, such as banning aerosols. Does this matter? I’d argue quite possibly not, because the most pressing science communication concern is arguably just getting people to believe in climate change, thus giving mandate to policy makers (who will choose from more viable solutions – there’s no suggestion that anyone is lobbying for them to ban aerosols).

What’s missing?

It’s highly surprising that the CRED manual doesn’t talk about ideological polarization and the types of messaging that might appeal to these different populations. This seems to me to be the area of climate communication research with the strongest empirical backing.

What’s left?

Not having read the underlying research, I am not sure how much credence I should give to the rest of the CRED recommendations – and there’s a lot of them. Notably:

  • Talk about avoiding losses rather than seeking gains
  • Choose a promotion or prevention focus for your messaging (although the above advice suggests we should focus on prevention!)
  • Work to prevent the single-action bias
  • Be careful what words you use to communicate uncertainty
  • Invoke the precautionary principle
  • Focus on immediate threats
  • Frame climate change as a local issue (CRED doesn’t give a citation, but Myers cites Hart and Nisbet 2011, O’Neill and Nicholson-Cole 2009)
  • Tap into emotion: CRED essentially advises climate communicators to appeal to both reason and emotion – but also to be aware of the pitfalls of appealing to emotion too much. It’s not clear how communicators are supposed to dig their way out of this conundrum.

Accordingly, I’m going to cheat a bit on the assignment and just make the following blanket statement: I won’t recommend that any of the speakers in this thought experiment read the CRED manual. There are, for me, too many uncertainties about its advice. But a more widely read communications researcher could probably go through the manual and revise it in a way that would be useful for our speakers.

Feygina’s system justification thesis

Source material: Feygina, Jost and Goldsmith. “System Justification, the Denial of Global Warming, and the Possibility of ‘System-Sanctioned Change.

The authors found that much of the effects of political conservatism and gender on environmental denialism can be explained by the subjects’ tendency to defend the societal and economic status quo. They also concluded that it is possible to eliminate the negative effect of this “system justification” by providing statements that frame environmental protection as patriotic and consistent with protecting the status quo.

I had some qualms with this paper’s findings – in particular Study 3, which examined the effect of presenting a system-preservation message (“being pro-environmental allows us to protect and preserve the American way of life,” etc.). The study used a sample size of just 41 and seems subject to the demand effect.

Myers’ public health framing

Source material: Myers, Nisbet, Maibach and Leiserowitz. “A public health frame arouses hopeful emotions about climate change.

The authors studied the effects of three climate change-related messages that framed the problem variously in terms of the environment, health and national security. Disaggregating the subjects into segments according to climate change knowledge, attitudes and behavior (with the six segments dubbed Alarmed, Concerned, Cautious, Disengaged, Doutbful and Dismissive), Myers found that a public health frame created the most hopeful response in a majority of these populations. She also found that the national security frame was most likely to generate anger, especially among the Dismissive and Doubtful.

Kahan: geoengineering and polarization

Source material: Kahan, Jenkins-Smith, Tarantola, Silva and Braman. “Geoengineering and Climate Change Polarization: Testing a Two-Channel Model of Science Communication.”

The researchers found they could offset cultural polarization over the validity of climate change by replacing a message advocating a lower atmospheric CO2 threshold with one in which scientists called for greater investment in geoengineering – applied technologies directed at combating climate change. Contrary to a competing hypothesis, Kahan et al found that subjects receiving information about geoengineering were slightly more concerned about climate change than were those in a control condition.

My main concern here is, why would geoengineering calm the polarizing effect of climate communication if renewable energy and other green technologies have not previously achieved this? The method – as Kahan puts it, “valorizing the use of human ingenuity” – is the same.

I also have serious reservations about the advisability of putting too much emphasis on geoengineering in the public discourse. The more airtime we give to this idea, the more legitimacy we lend it. And while geoengineering is certainly something that scientists should explore, right now it seems like it should be very far down our list of policy and funding priorities. There are many technologies for energy generation, improved electricity distribution and energy storage that are much closer to fruition than any proposed geoengineering technology, without the very serious risk of unknown side effects that geoengineering poses.

What to say?

Now, on to the assignment proper – my suggestions for our speakers:

President Obama

Some of the study results suggest Obama should modify his message to appeal to voters not already on his side. 

Meyers’ work suggests President Obama could try to emphasize the public health benefits of his proposal, and the administration already seems to have got the memo on that. Obama should not, however, use a national security angle, which is likely to anger those most skeptical about anthropogenic climate change. Feygina’s work suggests that additionally, Obama could talk about his proposal as a means of protecting the “American way of life,” i.e. the status quo. Obama could try reframing the proposal as a form of system maintenance rather than radical change – perhaps he could talk about his proposal as a natural extension of the previous cap and trade system introduced by a Republican president. Not surprisingly, Obama has tried this too, although perhaps he hasn’t stressed the point enough.

Kahan’s findings could be applicable on a broad scale – not to suggest that Obama should speak about geoengineering specifcally, since that’s not his policy aim; but that part of his reframing effort could include talk of human ingenuity. Once again, I think this has been tried, in the context of renewable technologies.

By his very role, and by public perceptions, Obama is rather hamstrung. He can’t really de-politicize his message. Feygina’s study notes (the abstract is actually a bit misleading on this point) that system justification did not fully account for political orientation’s effect on environmental attitudes, and suggests that “top down” factors such as official party platforms are also at work. There’s also the possibility that when Obama engages in re-framing (such as talking about making the US more secure, by reducing dependence on foreign oil), this is seen by conservative voters as a transparent ploy. Myers notes that important factors in real world communication, not reflected in her experiment, include the congruence between messenger and frame.

Zoning board member

The key for this official is that he doesn’t really have to mention “climate change” at all. I’m not suggesting that he suppress such talk, but it’s really not necessary to get the adaptation measures passed. The term “climate change” is inherently polarizing, and people can recognize the need to protect infrastructure from storms with or without a belief in man-made global warming.

Myers’ study suggests it may be useful for the board member to use a public health frame for the discussion, which would be natural when one is talking about the need to safeguard against flooding, etc. Feygina’s recommendations would also be easy to accommodate, as climate change adaptation on a broad scale involves protecting the “status quo” (ie, protecting the city against the forces of nature), although property owners and politicians may in reality have to start doing things very differently. It proabbly wouldn’t hurt to emphasize the human ingenuity and industry aspects of the officials’ approach, but this may not strictly be necessary as without talk of “climate change,” there may not be polarizing language in need of neutralization.


Kiwanis International is a service club that emphasizes efforts to improve children’s lives. Feygina’s recommendations may or may not be necessary here, depending on the system-protection beliefs of the participants – but putting them into practice probably wouldn’t hurt. Myers’ work would point towards using a health frame here, perhaps focusing on preserving environmental quality to reduce childhood asthma, etc., and I see little drawback to doing so. Kahan’s work suggests that making reference to human ingenuity could help to neutralize some of the polarization that talk of climate would have on the more hiearchical/individualist members of the organization, though I have concerns about over-emphasis on geoengineering, as discussed above. 

Superbowl ad consultant

Feygina’s work would be useful because the ad must appeal to a broad spectrum of Americans, including those averse to changing the status quo. Again I see health framing as useful and don’t see any obvious drawbacks to such an approach; likewise an emphasis on human ingenuity. My concerns about geoengineering, outlined above, are even stronger for the ad than for a one-off talk at a Kiwanis club, since the message would reach many millions of people and be repeated often, thereby completely exaggerating the importance of geoengineering within the range of climate change approaches.

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Note: I have joined the “virtual class” component of Dan Kahan‘s Science of Science Communication course at Yale University. As part of this I am endeavoring to write a response paper in reaction to each week’s set of readings. I will post these responses here on my blog – my paper for week six is below. Previous responses are here.

I will also be participating in the discussion on Kahan’s own blog.

Graphic from home page of the Consensus Project, led by researcher John Cook. Skeptical Science Graphics (Skeptical Science) / CC BY 3.0

Since the publication of John Cook’s 2013 study confirming climate scientists’ 97 percent consensus on humans’ responsibility for climate change, many science communicators have vigorously argued the importance of “teaching the consensus.” On a common-sense level, teaching the consensus seems like an obviously good idea. If you tell someone that 97 percent of experts on a subject agree, how could he carry on maintaining the minority position?

But science communication isn’t that simple. It’s much more frustrating, and fascinating.

Evidence for “teaching the consensus”

From Lewandowsky et al, The pivotal role of perceived scientific consensus in acceptance of science, Nature Climate Change, Oct. 2012.

From Lewandowsky et al, The pivotal role of perceived scientific consensus in acceptance of science, Nature Climate Change, Oct. 2012.

Let’s have a brief look at some of the evidence for teaching the consensus – which is backed not just by common sense but by several studies. Stephan Lewandowsky, in particular, has been a strong proponent of this approach. In “The pivotal role of perceived scientific consensus in acceptance of science,” he and his colleagues found that subjects told about the 97 percent scientific consensus expressed a higher certainty that CO2 emissions cause climate change – 4.35 on a 5-point Likert scale, versus 3.96 for members of a control group not exposed to the consensus message.

In addition, the consensus message appeared to have effectively erased ideology’s influence on global warming opinions. Those exposed to the message had a high level of agreement that CO2 causes climate change, regardless of their free-market ideology; whereas in the control condition, free-market endorsement was associated with a marked decrease in acceptance of human-caused climate change (see chart above).

Meanwhile, back in the real world…

But Dan Kahan points out that these findings don’t seem borne out by real-world evidence. From 2003 to 2013, the proportion of the US public who said human activities were the main cause of global warming declined from 61 to 57 percent.

During this period researchers published at least six studies quantifying the consensus, and there were also several notable efforts to publicize the consensus, including:

  • prominent inclusion in Al Gore’s documentary film and book “The Inconvenient Truth”;
  • prominent inclusion in the $300 million social marketing campaign by Gore’s Alliance for Climate Protections;
  • over 6,000 references to “scientific consensus” and “global warming” or “climate change” in major news sources from 2005 to May 1, 2013.

What accounts for this discrepancy? According to Kahan, “The most straightforward explanation would be that the NCC [Lewandowsky] experiment was not externally valid—i.e., it did not realistically model the real-world dynamics of opinion-formation relevant to the climate change dispute.”

What should consensus publicity look like?

I think there’s another possible explanation: that Lewandowsky did realistically model the changes in opinion that might happen with a concerted and well designed consensus-publicity effort – but that from 2003 to 2013, we did not actually see such an effort.

Kahan implies that messaging during this period was widespread and well-funded. But was it as widespread as we would need such a campaign to be? And were the campaigns carried out in the best manner possible? For example, did the communicators use the best dissemination methods, the best language and the best graphical representations? Should they have targeted different populations with different, tailored messages?

I would like to see a more comprehensive analysis asking the questions:

  • What did communication of the climate change consensus from 2003 to 2013 consist of? and
  • Did it meet certain criteria that we should require of such a campaign?

Whether the actual consensus messaging carried out from 2003 to 2013 had the same characteristics that made Lewandowsky’s messaging effective, I could not say. But it certainly seems worth investigating what those characteristics might be. Of course, a prime concern is to discover if those characteristics include or depend on the artificial psychology lab environment – which would indicate that it is impossible to influence climate change opinions through consensus messaging in the real world.

An aside on sample size

I also note that Kahan doesn’t question the validity of Lewandowsky’s sampling. I can’t help wondering if Lewandowsky’s findings might not be, in some part, an artifact of small selection size.

The researchers compared a control group of 47 to a consensus condition group of 43. This means they were not literally testing the effect of consensus messaging on individual participants, but concluding that the difference in opinions between the two groups was due to the consensus messaging that one group received.

While this approach is advisable (a literal “before and after” set-up presents the problem of demand effect, as our class saw in its examination of Ranney et al,) it also depends on a large enough sample size to minimize the possibility that uncontrolled and unseen variables are affecting results. I’m not convinced that Lewandowsky’s sample size was large enough for that.

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