by Judith Curry
A new report from The University of Nottingham looks at whether climate scientists threaten their own scientific credibility when trying to make their research accessible to members of the public.
A new paper is published today in Nature Climate Change [link]:
Tension between scientific certainty and meaning complicates communication of IPCC reports
G. J. S. Hollin andW. Pearce
Abstract. Here we demonstrate that speakers at the press conference for the publication of the IPCC’s Fifth Assessment Report (Working Group 1) attempted to make the documented level of certainty of anthropogenic global warming (AGW) more meaningful to the public. Speakers attempted to communicate this through reference to short-term temperature increases. However, when journalists enquired about the similarly short ‘pause’2 in global temperature increase, the speakers dismissed the relevance of such timescales, thus becoming incoherent as to ‘what counts’ as scientific evidence for AGW. We call this the ‘IPCC’s certainty trap’. This incoherence led to confusion within the press conference and subsequent condemnation in the media. The speakers were well intentioned in their attempts to communicate the public implications of the report, but these attempts threatened to erode their scientific credibility. In this instance, the certainty trap was the result of the speakers’ failure to acknowledge the tensions between scientific and public meanings. Avoiding the certainty trap in the future will require a nuanced accommodation of uncertainties and a recognition that rightful demands for scientific credibility need to be balanced with public and political dialogue about the things we value and the actions we take to protect those things.
From the press release from the University of Nottingham:
In the last 25 years scientists have become increasingly certain that humans are responsible for changes to the climate. However, for many politicians and members of the public, climate change is still not a particularly pressing concern. In a new report – ‘Tension between scientific certainty and meaning complicates communication of IPCC reports’ – published on Nature Climate Change’s website, Dr Gregory Hollin and Dr Warren Pearce from the University’s School of Sociology and Social Policy, look at a press conference held by the IPCC in 2013 in order to better understand the ways in which climate scientists attempt to engage the public through the media.
Dr Pearce says: “Climate science draws on evidence over hundreds of years, way outside of our everyday experience. During the press conference, scientists attempted to supplement this rather abstract knowledge by emphasising a short-term example: that the decade from 2001 onwards was the warmest that had ever been seen. On the surface, this appeared a reasonable communications strategy. Unfortunately, a switch to shorter periods of time made it harder to dismiss media questions about short-term uncertainties in climate science, such as the so-called ‘pause’ in the rate of increase in global mean surface temperature since the late 1990s. The fact that scientists go on to dismiss the journalists’ concerns about the pause – when they themselves drew upon a similar short-term example – made their position inconsistent and led to confusion within the press conference.”
Dr Hollin says: “Climate change communication is anything but straightforward. When trying to engage the public about climate science, communicators need to be aware that there is a tension between expressing scientific certainty and making climate change meaningful. Acknowledging this tension should help to avoid in the future the kind of confusion caused at the press conference.”
Climate change is an area where consistent attempts are made to communicate the certainty of the science. As a result, a spotlight on scientific uncertainties may be seen as unwelcome. However, Dr Hollin and Dr Pearce argue that a discussion of uncertainty may be an unavoidable by-product of attempts to make climate change meaningful.
Dr Pearce adds: “In the run-up to the United Nations climate summit in Paris, making climate change meaningful remains a key challenge. Our analysis of the press conference demonstrates that this cannot be achieved by relying on scientific certainty alone. A broader, more inclusive public dialogue will include crucial scientific details that we are far less certain about. These need to be embraced and acknowledged in order to make climate change meaningful.”
From the authors’ blog post at Making Science Public. Below are excerpts, go to the original blog post to see the diagrams from the paper:
What we found is that, in attempting to demonstrate the importance of climate change, scientists actually became inconsistent about ‘what counts’ as scientific evidence and this led to confusion and condemnation in the press.
Phase One: Increasing certainty
Since the last IPCC report, certainty over the nature of climate change has increased and, unsurprisingly, scientists at the press conference stressed this increase:
“the evidence for human influence has grown since Assessment Report 4, it is now deemed extremely likely that human influence has been the dominant cause of the observed warming.”
However, and as noted above, academics from the social sciences and humanities have argued that climate change has yet to attain enough public meaning to prompt significant personal, political and policy responses.
Phase Two: Making climate change meaningful: Intention
Within the press conference, scientists tried to use the certainty of climate change to demonstrate that it is meaningful and that ‘we’ must take action:
“[The] report demonstrates that we must greatly reduce global emissions to avoid the worst effects of climate change.”
We argue that this is what the scientists wanted to achieve in the press conference: retaining the certainty of the report while adding meaning.
Phase Three: Making climate change meaningful: Reality.
There was, however, an inconsistency in the argument of the scientists. Scientists consistently drew on short-term temperature increases in order to give climate change meaning:
“the decade 2001 onwards having been the hottest, the warmest that we have seen”.
However, the scientists also understood these short-term temperature increases to be less certain than the overall theory of climate change:
“periods of less than around thirty years. . . are less relevant” .
Thus, the meaningful, short-term, temperature changes were actually incorporated at the expense of certainty. Meaning had been added but at the expense of certainty.
Phase Four: Inconsistent attempt to maintain public meaning and certainty.
Drawing on meaningful information like ‘the hottest decade’ proved problematic for the scientists for it is hard to see why the short-term increase in temperature during ‘hottest decade’ is very different from the short-term decrease in temperature witnessed during the 15-year ‘pause’. Journalists repeatedly asked scientists about the pause and, in particular, how they could be increasingly certain about climate change in the face of such an uncertainty:
“Your climate change models did not predict there was a slowdown in the warming. How can we be sure about your predicted projections for future warming?”
Faced with these questions, scientists insisted that short-term temperature changes were irrelevant for climate science:
“we are very clear in our report that it is inappropriate to compare a short-term period of observations with model performance” .
Given the type of statement we saw during phase three it is perhaps unsurprising that this retreat led to confusion, incoherence, and criticism within the press conference.
Climate change is an area where consistent attempts are made to communicate the certainty of the science. As a result, a spotlight on scientific uncertainties may be seen as unwelcome. However, in the run-up to the United Nations climate summit in Paris, making climate change meaningful remains a key challenge and our analysis of the press conference demonstrates that this meaning-making cannot be achieved by relying on scientific certainty alone. When trying to engage the public about climate science, communicators should be aware that there is a tension between expressing scientific certainty (and focusing on longterm trends) and making climate change meaningful (by focusing on short-term trends) and, what is more, that this tension may be unavoidable. A broader, more inclusive public dialogue will have to include crucial scientific details that we are far less certain about and these need to be embraced in order to make climate change meaningful.
Rather amazing that Nature Climate Change published this paper; in any event I am certainly pleased that they did.
The strategy of hyping certainty and a scientific consensus and dismissing decadal variability is a bad move for communicating a very complex, wicked problem such as climate change. Apart from the ‘meaningful’ issue, its an issue of trust – hyping certainty and a premature consensus does not help the issue of public trust in the science.
This new paper is especially interesting in context of the Karl et al paper, that ‘disappears’ the hiatus. I suspect that the main take home message for the public (those paying attention, anyways) is that the data is really really uncertain and there is plenty of opportunity for scientists to ‘cherry pick’ methods to get desired results.
Apart from the issue of how IPCC leaders communicate the science to the public, this paper also has important implications for journalists. The paper has a vindication of sorts for David Rose, who asked hard hitting questions about the pause at the Stockholm press conference.
Kudos to the Nottingham team for a very insightful paper. I look forward to visiting the University of Nottingham in two weeks, where I will be attending the Conference on Circling the Square.