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Nine lessons and carols in communicating climate uncertainty

About a month ago I was invited to represent the Cabot Institute at the All Parliamentary Party Climate Change Group (APPCCG) meeting on “Communicating Risk and Uncertainty around Climate Change”. All Party Groups are groups of MPs and Lords with a common interest they wish to discuss, who meet regularly but fairly informally. Here are the APPCCG registerblogTwitter and list of events.

The speakers were James Painter (University of Oxford), Chris Rapley (UCL) and Fiona Harvey (The Guardian), and the chair was (Lord) Julian Hunt (UCL). Rather than write up my meeting notes, I’ll focus on the key points.

[Disclaimer: All quotes and attributions are based on my recollections and note-taking, and may not be exact.]

1. People have a finite pool of worry

I'll start with this useful phrase, mentioned (I think by Chris) in the discussion. Elke Weber describes this:

"As worry increases about one type of risk, concern about other risks has been shown to go down, as if people had only so much capacity for worry or a finite pool of worry. Increased concern about global warming may result in decreased concern about other risks...the recent financial crisis reduced concern about climate change and environmental degradation." -- “What shapes perceptions of climate change?”; pdf currently here)

Lessons: We cannot expect or ask people to worry about everything: concern about other issues can reduce concern about climate change, while evoking strong emotions about climate change can reduce concern about other issues. So Chris encouraged talking about opportunities, rather than threats, wherever possible.

2. People interpret uncertainty as ignorance

People often interpret the word "uncertainty" as complete ignorance, rather than, for example, partial ignorance(..!) or a well-defined range of possible outcomes. This may be due to language: "I'm not certain" is close to "I don't know".

Just as important is exposure to research science. Science is often presented as a book of facts, when in fact it is a messy process of reducing our uncertainty about the world. At a school this year the head teacher told us about an Ofsted inspection during which they had a fantastic science workshop, where groups of students solved challenging problems using real data. At the end of the day, the inspector said: "Fine, but wouldn't it have been quicker to have told them the answer first?"

Lessons: Revolutionise the education system.

3. People are uncomfortable with uncertainty

Even when people do understand uncertainty, it can become a convenient rug under which to brush difficult decisions. Chris said that over-emphasising uncertainty leads to decision-making paralysis. When a decision invokes fear or anxiety (or, I would add, political disagreement), uncertainty can be used to dismiss the decision entirely.

"The Higgs boson", Chris said, "was not a ball bearing found down the back of sofa, but a statistical result". It was just possible it hadn't been discovered. But it wasn't reported this way. The Higgs, of course, does not invoke fear, anxiety or political disagreement (though please leave comments below if you disagree).

Lessons: Decision paralysis might be reduced by talking in terms of confidence rather than uncertainty. But perhaps more importantly...

4. People do accept the existence of risk

Finite worry and the problems of talking about uncertainty need not mean deadlock, James and Chris argued, because people do understand the concept of risk.  They accept there are irreducible uncertainties when making decisions. Businesses are particularly familiar with risk, of course. James mentioned that Harvard Business School is actively viewing climate change in this way:

"It's striking that anyone frames this question in terms of 'belief,' saying things like, 'I don't believe in climate change,'… I think it's better seen as a classic managerial question about decision-making under uncertainty." -- Forest L. Reinhardt, Business and Environment Institute faculty co-chair, HBS

Viewed in this way, the problem is not whether to make a decision based on uncertain or incomplete information, which is nearly always the case in other spheres (Chris: “Why should climate change be a special case required to have absolute certainty?”). The problem is whether the decision made is to bet against mainstream climate science:

"It seems clear that no one can know exactly what's going to happen--the climate is a hugely complex system, and there's a lot going on"....[The vast majority of the world's scientists] may be wrong. But it seems to me foolish to bet that they are certainly wrong." -- Rebecca Henderson, Business and Environment Institute faculty co-chair, HBS

Chris pointed out that the Technical Summary of the latest Intergovernmental Panel on Climate Change (IPCC) assessment of climate science uses the word "uncertainty" a thousand times and the word “risk” not at all, so it is not surprising the media focus on uncertainty. And how well humans understand risk is a matter worthy of much discussion. But as James writes:

“There is... a growing body of literature suggesting that risk language may be a good, or at least a less bad, way of communicating climate change to the general public”. -- "Climate Change in the Media: Reporting Risk and Uncertainty", (Executive Summary, page viii)

Lessons: Where possible, talk in terms of risk not uncertainty; see for example the IPCC report on extreme weather and, naturally, our book Risk and Uncertainty Assessment for Natural Hazards.

5. Scientists have little training

Most of us are not well trained - perhaps hardly at all - in science communication. But we must consider how the way we present numbers affects their interpretation. In 2007, the IPCC said the likelihood that most of global warming since the mid-20th century was caused by greenhouse gas emissions was assessed to be greater than 90%. This year they made a similar statement but the likelihood was 95% or greater. Chris said that if a journalist asked, "What does it mean to increase from 90% confident to 95% confident?", a scientist could make this clearer with "[We think] the chance climate change is natural is now half as likely as before."

He also pointed out that we don't have training in how to deal with the "street fight" of the climate debate. In my experience, this is one of the two main reasons why most of my colleagues do not do public engagement (the other being time commitment).

Lessons: For communicating uncertainty and risk, I recommend For dealing with the street fight, my advice is first to start with a lot of listening, not talking, to get a feel for the landscape. And to talk to climate scientists already engaging on how to avoid and deal with conflict (if, indeed, they are avoiding or dealing with conflict...).

6. Journalists have little (statistical) training

The IPCC assessment reports use a "language" of uncertainty, where phrases such as "extremely likely" are given a specific meaning (in this case, 95% or greater likelihood). But James said that only 15% of media articles about this year's report explained the meaning of this uncertainty language.

And in the discussion someone quoted a journalist as saying "The IPCC report says it has 95% confidence – what do the other 5% of the scientists think?" In other words, confusing the idea of a consensus and a confidence interval. There was a laugh at this in the room. But I think this is easily done by people who do not spend all day thinking about statistics. That would be: the majority of the human race.

Lessons: Er, many journalists could benefit from more statistical training. Here is what that might look like.

7. "Newspaper editors are extremely shallow, generally"

Fiona, her tongue only slightly in cheek, gave us this memorably-made and disappointing (if predictable) point.

Just because something is important it doesn't mean it will get into a news outlet. An editor might go to a cocktail party, talk to their glamorous celebrity friends, hear some current opinion, and then the next day their paper says...

In other words, the social diary - including meetings with high profile climate sceptics - can have a substantial influence on the viewpoint taken. (Of course, she noted, the editor of The Guardian is a profound man, not influenced by such superficiality). To counter this we would need to go to influential people and whisper in their ears too. We would need to launch a prawn cocktail offensive - or more appropriately, as one wit suggested, a goats cheese offensive. You heard it here first. And last.

Lessons: Go to more cocktail parties hosted by influential people.

8. There are many types of climate sceptic

There was generally support of scepticism by the speakers. Chris said it was perfectly valid for the public to ask scientists "Can we see your working?"; in other words, to ask for more details, code and data. All the speakers said they don't use the word "denier".

James said we should not generalise, and described four types of sceptic: trend, attribution, impacts, and policy. A trend sceptic would not be convinced there is global warming; an attribution sceptic about how much is man-made; an impacts sceptic might say we don't know enough about when and how severe the impacts will be; and a policy sceptic would take issue with how to tackle the problem. (Personally, I believe there are as many types of sceptic as there are sceptics, but that would be a longer list to write down). Fiona pointed out that one person can be all these types of sceptic, moving from one argument to another as a discussion progresses. Some thought this would be incoherent (i.e. kettle logic, contradictory arguments) but others thought it could be coherent to be sceptical for more than one of those reasons.

Lessons: Treat each sceptic as an individual (flower); don't assume they are one type of sceptic when they may be another, or more than one.

9. Trust is important 

What determines people's views on climate change? As James pointed out, there is evidence that what drives opinions is not science, or even the media (they determine only the topics of discussion), but political, cultural and social values. Fiona had said earlier in the meeting, "Climate change is more politicised than ever before in my lifetime: it is becoming a matter of right or left. This is very, very scary. If you allow this, you lose any hope of doing anything sensible about it."

All this is true. But I'll end with a slightly more optimistic quote, which I think was from Chris: "The sea change in the battle with tobacco companies was when the message got across that the adverts were not trustworthy." I quote this not because I believe it is the same as the climate debate, and not because sceptics are untrustworthy (though some may be), but because I (some might say, choose to) interpret it to mean that trust is important. When people trust the messenger, the message is more likely believed.

Lessons: Other things are important, but sometimes communication is a matter of trust. I emphasise this point because it's what I already believe; others may disagree (politely, please...).


I would have liked to add more references supporting the points made by the speakers, but ran out of time. Some are in James' book mentioned above. Do please add them in the comments if you have them.

The title of this blogpost came from realising I had nine points to make and thinking of this set of shows curated by Robin Ince celebrating science, skepticism, and rationalism. If you're in the UK this December, do go.

This blog is written by Dr Tamsin Edwards, Geographical Sciences, University of Bristol and also features on her PLOS blog All Models Are Wrong.
Follow Tamsin on Twitter @flimsin
Tamsin Edwards

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