Angus Ferraro

A tiny soapbox for a climate researcher.


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Transformational Climate Science – approaching the problem of climate change

On 15-16 May a diverse group of climate researchers gathered at the University of Exeter to discuss the state of climate change following the publication of the IPCC Fifth Assessment Report and the future of the field. In a previous post I discussed some of the key themes. Here I’m going to summarise some of what went on at the conference in terms of how we should approach climate change.

How does the IPCC work? Is climate research doing what it should? Should it change?

Chris Field presents an overview of the AR5 WG2 report. Credit: University of Exeter via Flickr.

The Transformational Climate Science meeting had sessions structured around the three IPCC working groups (The Physical Science Basis; Impacts, Adaptation and Vulnerability; Mitigation of Climate Change). However, the IPCC is not the bottom line in climate research. It’s important to remember that its main role is to summarise our state of knowledge rather than to do new research (though it does do this as well to some extent). However, the IPCC remains a convenient ‘hook’ on which to hang our deliberations about climate change, which is presumably why the meeting was structured as it was.

As a physical scientist, I was looking forward to learning about working groups 2 and 3. Working Groups 2 and 3 (WG2 & WG3) bring together an astonishingly broad group of people: physical scientists, economists, sociologists, political scientists, philosophers…I got the impression the level of ‘cohesion’ was a little lower in these working groups than WG1. In WG1 everyone has different specialisms, but participants probably understand each others’ way of thinking well, whereas I don’t think that would be the case for people coming from diverse cognitive traditions in WG2 and WG3.

Aside from the need to bring together people with different expertise to cover the subject matter, there’s another benefit to this diversity. In the meeting a number of IPCC authors acknowledged their work could not be completely free of value judgements. By bringing together a diverse group of people, the hope is that at last a range of different value systems can be considered. A number of authors also made it explicit when they were trying to be objective and reporting ‘IPCC opinion’, and when they were talking about their own personal opinion.

One of the challenges faced by the authors of the WG2 report was the tendency of negative impacts of climate change to be reported more than positive ones. Sari Kovats, in her remarks, explicitly noted this and pointed out this was something authors were aware of and attempted to deal with as best they could. She also described what she saw as the problems in writing a report with limited quantitative research. She gave the example of the Russian heatwave and wildfires of 2010. We do not have a good idea of the impacts of this event on human health, economic productivity or food supply. In short, we lack good data. This problem becomes worse in less developed countries, which is understandable but frustrating since we might also expect such countries to be more vulnerable to climate risks.

I thought Sari’s presentation was one of the most interesting at the meeting. It described nicely what the state of the art is when it comes to studying climate impacts. She described the challenges of interpreting small-scale qualitative studies with the goal of drawing conclusions for quantitative assessments of climate risk. Then she outlined what she thought WG2 did well and what she thought it didn’t. This includes the problem that less developed countries do not have the demographic and health data needed to assess climate impacts, and that the report did much better at describing regional inequalities in impacts than it did the socioeconomic inequalities. In a globalised world, perhaps socioeconomic divides are as important as geographical ones.

Chris Field gave some thoughts on the role of WG2. He saw it as a prompt for discussion of publicly acceptable solutions – the start of a dialogue rather than its end. I found this extremely encouraging, and in line with previous discussions of the importance of considering the value systems of different stakeholders.

I admit to finding this surprising. I had rather lazily assumed that IPCC reports didn’t include discussion of normative aspects of climate science and policy. It was encouraging to see Simon Caney talk specifically about this point. For the first time the WG3 report included a section on ethics. He pointed out that ‘dangerous’ is a value judgement, and it was vitally important to consider peoples’ values. He gave the example of people who say ‘we should do whatever it takes to tackle climate change’. They almost certainly don’t mean that. Caney pointed out that different people have different priorities, but that it was unlikely anyone genuinely things climate change is the only priority.

Such perspectives are very valuable. Caney also brought in the view that the ‘right to emit’ is an odd concept. What matters for people is the access to energy to enable them to fulfil their requirements. He argued that Amartya Sen’s perspective on serving capabilities was more relevant than considering every person’s equal right to emit greenhouse gases. The emissions are a side-effect of the requirement for energy, and we should view responses to climate change in terms of serving capabilities rather than picking out such a side-effect.

One final thought – Saffron O’Neill pointed out that media coverage of WG1 is greater than either WG2 (one third less) or WG3 (three quarters less). Interestingly, the amount of Twitter activity on the conference hashtag also seemed lower during WG2 and WG3 sessions. It’s interesting to consider why this might be the case. One simple reason might be that the WG1 report is released first. But is there something deeper here? Do we ‘value’ the explicit and factual nature of WG1 more than the difficult, fuzzy, value-laden world of WG3? Perhaps, but I think that’s a shame. It seems especially odd that those who self-identify as ‘sceptics’ focus so much on WG1, when there’s a whole lot more stuff up for legitimate debate in WG2 and WG3.

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Transformational Climate Science – meeting report

On 15-16 May 2014, the University of Exeter hosted an impressive array of climate change researchers from across the world. It was a medium-sized conference discussing the state of climate change research across all three working groups of the Intergovernmental Panel on Climate Change, along with goals and challenges for the future.

I found the meeting absolutely fascinating for all manner of reasons, most of which I hope to cover in two following blog posts. This post is something of an introduction.

Conference attendees gathering in the University of Exeter’s Forum. Credit: University of Exeter via Flickr.

One of the most obvious draws for me was that it brought together people from all three IPCC working groups. As a physical scientist I am familiar with the workings and results presented by the first working group, but the other two are rather more mysterious to me. This meeting served as a great summary. In case you’re not aware, the IPCC reports are produced by three separate groups:

These working groups operate rather separately. Once they have all released their reports they are combined in a synthesis report. The synthesis report for the Fifth Assessment goes to governments in October 2014. So, where next?

In the next two blog posts I’m going to discuss two themes which I felt ran through the conference.

The first is: how should we approach climate change? What kind of discussions should we be having, and how should they work? How should decisions be made?

The second is: what is the future of climate research? What information do we need and how can we get that information?

These questions are clearly inter-related. The first question is more of a political one, but the second one is clearly also politically relevant, as ultimately the choice of what information we need lies with policymakers and the public. This is one of the over-arching topics which transcended both of the themes: that climate research and policymaking is a mixture of facts and values. In simple terms: it is a fact that the planet has warmed, will continue to warm to a greater or lesser degree, and that this warming will have impacts. However, what we do about it (or indeed whether we do anything about it) is a question of values. It is a normative question in which there is no single right answer.

Even though facts might be seen as ‘valueless’, many of the speakers at the meeting argued there was no such thing. Asuncion St Clair quoted Bruno Latour: ‘no knowledge is neutral’. The way facts are presented requires the imposition of some kind of value system. Ottmar Edendorfer said at the conference that he sees the role of the IPCC as akin to that of a map-maker. The map-maker doesn’t tell the user which route to take. The map-maker examines the landscape and maps out the features, obstacles and characteristics of all paths. And yet the map-maker can’t just present the ‘facts’. The choice of what goes on the map depends on what the map-maker thinks the user needs. Take, for example, the difference between political and topographic maps. One presents largely artificial boundaries between nation-states; the other presents details of the landscape. Which one you choose would depend on your needs.

Even though it’s not possible to be completely neutral, then, perhaps the IPCC could try to address this problem by providing as much information as possible. Of course, this doesn’t make it very readable and that’s why there are two summaries that attempt to make the make points easier to grasp: the Summary for Policymakers (the content of which has to be agreed to by governments) and a Technical Summary (which doesn’t). But the choice of what goes in there might also be normative.

Given its stated goal to be ‘policy relevant, not policy prescriptive’, and the enormous complexity of its subject matter, the IPCC often makes very careful statements emphasising precisely what we do and do not know. Chris Field pointed out that this leads to something of a problem. He said that some of the statements turned out so vague that they were open to almost any interpretation. Different media outlets could make very different readings of the report and come to sometimes diametrically opposed conclusions!

This raises the issue of framings. ‘Framing is everything in this debate’ said Georgina Mace. What this means is that, given a more-or-less neutral presentation of information there is no single implication that naturally comes out. The implications of the findings of the IPCC depend on how one views the world. At the meeting Saffron O’Neill presented the results of some of her work on media framing of AR5. Common frames included: ‘settled science’, ‘unsettled science’, ‘security’ and ‘morality and ethics’. She pointed out that different frames implied very different policy options.

In the coming blog posts I hope to draw out some more detail on the two main areas of the conference: how should we approach climate change and what is the future of climate research? After all that talk of framings it’s important to say that these are my personal impressions, and not an objective report. If you want to find out exactly what went on at the meeting, you can catch up on the presentations and panel discussions on the website.

Other coverage:


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How do we decide whether geoengineering is worth it?

Citation: A J Ferraro, A J Charlton-Perez, E J Highwood (2014) PLOS ONE, doi:10.1371/journal.pone.0088849

Some have proposed we take a different approach to climate change and attempt to stop global warming by reflecting sunlight. We have a new paper out today which asks the question: how do we decide whether such geoengineering would be effective?

Maps of climate model simulations using the risk matrix. The simulation uses stratospheric aerosols to balance the surface warming from a quadrupling of carbon dioxide.

Maps of effectiveness of geoengineering using a risk approach. The simulation uses stratospheric aerosols to balance the surface warming from a quadrupling of carbon dioxide.

Does geoengineering have the potential to reduce climate risk?

One way to exert a cooling influence on the climate would be to pump tiny particles up into the stratosphere, where they would reflect a small amount of the Sun’s energy. Should we consider intentionally modifying our environment in this way in order to affect the climate? Some argue there is a chance of unintended side effects, and that such meddling is too risky. Others argue the opposite: that it is too risky to allow global warming to continue.

What are these risks? A basic way to think about it is that people are adapted to our present climate. They are used to a particular mix of warm and cold, wet and dry. As climate changes, this mix will also change, posing a risk to those not prepared for it. For example, a warmer climate might be seen as a risk for healthcare systems not equipped to deal with medical problems associated with heat waves. A wetter climate might increase the risk of flooding. Risks like this could be costly – which is essentially why climate change could pose a problem.

Could geoengineering be used to help? Geoengineering with stratospheric aerosols might pose risks of its own: reduced rainfall, depletion of the ozone layer. It might also produce benefits: reduced warming and enhanced agricultural productivity. We need a way to compare the risks and benefits of geoengineering with the risks and benefits of not geoengineering (here, we are assuming we don’t do a good job of reducing greenhouse gas emissions).

How do we weigh up different kinds of risk?

Consider this: you are diagnosed with a medical condition which may deteriorate in future and cause you difficulty. You are given the option of a treatment which might stop the symptoms of the disease but may also have other side-effects. Do you take the treatment? You have to weigh up the risks.

A matrix showing the different outcomes of geoengineering. On the horizontal axis is the probability of a big climate change under carbon dioxide. On the vertical axis is the probability of a big change in climate under geoengineering.

A matrix showing the different outcomes of geoengineering. On the horizontal axis is the probability of a big climate change under carbon dioxide. On the vertical axis is the probability of a big change in climate under geoengineering. [EDIT: Thanks to the reviewer who suggested this method of presentation!]

In the same way we have to weigh up the risks to decide whether geoengineering is worthwhile. We would want it to reduce climate risk compared to not geoengineering. But there’s another layer of complexity here. Perhaps the reduction in risk happens somewhere that wasn’t actually at high risk of big climate changes in the first place. So perhaps no one cares?

We looked at this by dividing climate risk into four possible outcomes, shown in the diagram on the left. The horizontal axis shows the chance of getting a substantial climate change in the first place from carbon dioxide. The vertical axis shows the chance of getting a substantial change from geoengineering. So, if geoengineering reduces climate risk but there wasn’t much risk to start with (low change of substantial climate change on the horizontal axis). we classify geoengineering as ‘benign’ (it hasn’t really done much). If geoengineering reduces risk where carbon dioxide increases risk we classify geoengineering as ‘effective’. But what if geoengineering increases risk? We classify it as ‘ineffective’ if geoengineering introduces climate risk in a similar manner to carbon dioxide. Finally, if geoengineering introduces climate risk into areas which were not previously at risk from carbon dioxide-driven climate change, we classify geoengineering as ‘damaging’.

This way of looking at things can be used to classify climate changes. The maps in this post give an example: temperature and precipitation from a climate model. The ‘global warming’ case involves a climate with levels of carbon dioxide four times what we have now, and a climate about 4 degrees C warmer. The ‘geoengineering’ case uses stratospheric aerosols to counterbalance this warming. So as expected, if you look at temperature, geoengineering is largely effective. But rainfall looks rather different. Geoengineering is not effective in quite large parts of the globe.

Trade-offs

We have made some subjective choices here, and different choices would give quite different results as to the effectiveness of geoengineering. To further complicate things, I would expect different climate models to paint quite different pictures of regional changes.

Geoengineering isn’t necessarily good or bad. It involves a trade-off between risks. These risks are different for different aspects of climate. As these (and many previous) results have shown, it might not be a good idea to use geoengineering to counterbalance all warming, because this would produce large rainfall changes. Approaches like the one described here could be used to find what the optimum level of geoengineering is that would minimise changes in both temperature and rainfall.


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Climate policy is a question of values as much as it is a question of science

There has been a lot of discussion recently about how climate scientists should engage with climate policy, sparked mostly by Tamsin Edwards’ post on the Guardian’s Political Science blog. I didn’t intend on jumping in because I’m not sure I have much new to add, but perhaps I should put it on the record anyway.

Stick to what you know

I would encourage scientists to speak out on what they know (i.e. science). The claims of climate ‘sceptics’ who deny basic greenhouse theory are easy to refute, and we should be doing that. In fact, by and large we are doing that.

But it’s really not clear to me why a climate scientist should use their position of authority to argue for specific policies. Policy is a democratic process. Scientists shouldn’t abuse their position to give their values the loudest voice. Those on the left who call for them to do so might not always like what they hear. What if a climate scientist proposes using natural gas from fracking as a bridge fuel? What if they come out in support of market-driven responses to climate change, like a cap and trade system? These are views they are entitled to have, of course, but they are outside their area of expertise. They are views partly based on values.

The question of what should be done about climate change is a policy question and should be debated as such. Of course, ‘what should be done’ is influenced by what we think we know about future climate, but that is by no means the only influence. The response to climate change encompasses so many other factors, each as important as the physics of the climate system: engineering and technology, spending and taxation choices, international diplomacy, and democratic representation of values and priorities of the population.

A question of values

The fact is, it is not obvious what to do about climate change. Assuming we have a finite pot of money to spend on a range of policies, it’s not obvious that climate change is top of the list. What about improving energy access to the billions without it? Even if we assume climate change is top of the list, how do we go about reducing our emissions? Taxation, perhaps? How should that tax be designed? How progressive should that tax be? What kind of ‘energy mix’ should that taxation system be striving towards?

These are all important questions which have little to do with climate science, and everything to do with value judgements. In an ideal world we decide on a policy through a mix of democratic discussion (including everyone) and expert input (recognising that some people know more about policy options than others). Most climate scientists cannot claim to be policy experts. As citizens it is their right to engage in the discussion about what should be done, but it’s irresponsible to place themselves as experts when they’re not. It helps no-one.

A crystal-clear separation of science and policy would prevent them from hiding behind ‘but the science isn’t settled’ and force dissenters to articulate why they actually object.

Some object because they perceive calls for climate action as a critique of their wasteful, consumption-based way of life, and they simply can’t handle that critique. Some object because they see climate policy as something which can only be driven by the State, which they mistrust. There may be a way to deal with these objections and move forward with good climate policy, but only once we remove the scientific veil and address why they really object.

What kind of world do you want?

For advocacy groups, the science is somewhat irrelevant. They know what kind of world they want to live in already. The Taxpayers’ Alliance knows what kind of world it wants to live in. Greenpeace know what kind of world it wants to live in. Neither of their conceptions of the world is determined by climate science. They will inevitably use scientific conclusions to back up their pre-conceived notions of how the world should be.

For example, an overzealous left might institute climate policy which is inconsistent with the science. Perhaps they assume climate change is reversible (on near-term timescales it just isn’t). Perhaps they waste public money compensating people for extreme weather events despite plenty of scientific uncertainty about the link between climate change and weather extremes. I don’t know what they might do, but it’s important that everyone gets the correct scientific information, because otherwise everyone will just twist what little science they know to fit with how they want the world to be. If scientific errors are highlighted, it is up to the policymaker to justify their choices in other ways. The left could justify by talking about their particular values, but once again, that’s not to do with science.

Policy options are as much a matter of values as ‘good’ and ‘bad’. Scientists aren’t policy experts, and shouldn’t pretend to be. If they pretend, they enable dissenters to set up a strawman and dismiss both the particular policy they are pushing and the generality of the science. If scientists (in their professional capacities) stick to describing the consequences of certain policies their credibility as honest brokers is strengthened. Policymakers can then make policy choices based on credible facts and the values and preferences of the citizenry. Climate scientists are free to hold and express policy views, but in my opinion they should be very careful about doing so when they are speaking in a professional capacity.


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Scientists as informers of public policy

I have just come out of the EGU session on geoethics and jotted down a couple of thoughts in my notepad. One of the speakers told us about placements their organisation (Geology for Global Development) coordinates help scientists learn about social and ethical issues and how they relate to their research.

He specifically mentioned teaching of participatory decision-making.

I feel that the concept of participatory decision-making is tricky for scientists. Science, as a method of inquiry, is based on the idea that there is a single result, a clear truth to be uncovered.

So then, scientists might have a natural tendency to think that experts would always make the best decisions, and that these decisions can be improved by increasing knowledge.

In the reality of public policy, on scales from family units to nations to the global community, there is no objective best policy. The consequences of each policy are dependent on the set of values and.opinions through which it is viewed. Essentially, people make things complicated. The natural world can be shown to behave according to certain laws. Approaches using game theory attempt to do the same with humans, but it is clear that social and cultural differences among humans affect their decision-making preferences. Essentially, as a wealthy white male living in the UK I am not in a position to define how the life of a woman in a drought-afflicted African country would be best improved.

In reality there is no ‘best’ policy, only consequences affecting different people in different ways. We need to map out these consequences (making use of scientific information, of course) to make an informed decision in a democratic fashion. This is why we need participatory decision-making.


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RMetS meeting report: Quantifying Uncertainties in Climate Science

A man with a watch knows what time it is. A man with two watches is never sure.

Segal’s law

Scientific results are uncertain. That is, we can’t have complete confidence in them. Science requires that we have very high confidence in our results, but it is difficult to demonstrate scientifically that something is 100% true. This applies to all science, and climate science is no different. ‘Quantifying uncertainties in climate science‘ was the topic of last Wednesday’s meeting of the Royal Meteorological Society.

What is uncertainty?

Uncertainty tells us how sure we are that a result lies in a particular range. Uncertainty doesn’t imply that don’t know anything. It implies that we know something with a certain amount of confidence. For example, if I were to ask you what time it is now without letting you look at the clock, you are unlikely to estimate that it 1:57 pm (which in this example is the true time). Since you don’t have a clock to look at you must estimate based on what the time was last time you looked at the clock and your perception of how much time has passed since then. Since you are unlikely to be able to estimate the passage of time that accurately, you might estimate somewhere between 1:45 and 2 pm. You can be uncertain about what time it is and yet know that it’s certainly not 9 am. Uncertainty tells us how confident we are and helps us truly understand exactly what we know and what we don’t know (e.g. we know it’s the afternoon, but we don’t know whether it’s before or after 2 pm).

We can think about uncertainty in terms of probability. For example, we can say there is a probability of 0.95 that it is between 1:45 and 2 pm. If we were certain that the true time was between 1:45 and 2 pm the probability would be 1.00.

Why should we think about it?

Jonty Rougier of the University of Bristol gave a concise and eloquent explanation of the power of thinking in terms of uncertainty. It is extremely hard to make good policy decisions without it. He used the example of sea-level rise. If sea level rises by a small amount it would be cheaper to do nothing rather than take action by building flood defences. If it rises a lot then it would be cheaper to act rather than face the costs of the sea-level rise. To work out what the best option is we must work out how much sea level is going to rise.

Projections of climate change are always uncertain. There are three main sources:

  • Model uncertainty. Since we are going into the future we must use models. Models are not perfect, so they introduce uncertainty.
  • Scenario uncertainty. This is the future. We don’t know what’s going to happen. We don’t know how future population and energy systems will change, for example.
  • Natural variability. This is uncertainty that comes from ‘random’ variation in weather conditions. Even if the globe warms there will be periods of cold weather. This means that, although the global temperature is expected to be warmer than today in a decade or two, any single year might be colder. If you count up the warmer years and the colder years, there will be more warmer ones. Natural variability means the precise temperature of a given year is quite uncertain.

Sources of uncertainty in future global temperatures, from Ed Hawkins (University of Reading).

So we don’t know exactly how much sea level will rise. It depends on a wide range of things. But if we work out how uncertain we are we can say how probable it is that a certain amount of sea-level rise actually happens. Then we can work out, based on the range of possible sea-level rises, which is the most cost-effective course of action.

How to calculate it and how to reduce it

David Sexton (Met Office) spoke about the UK’s climate prediction programme, UKCP09 (lots of information available on their website) which goes to a great deal of trouble to come up with useful uncertainty estimates. Lindsay Lee (University of Leeds) spoke about sources of uncertainty in the effect of aerosols (tiny particles of dust, soot, sea salt, sulphuric acid and other substances) on the climate system. Aerosols generally cool the climate, but specific types can in fact produce warming. The processes that affect aerosols are very difficult to model because they happen on such tiny scales. Imagine trying to track millions of tiny particles each a thousandth of a metre across – impossible! Our models can only approximate their effects and that introduces uncertainty.

Tamsin Edwards (University of Bristol) spoke about using information from the distant past (thousands of years ago) to work out how much climate changes for a given change in carbon dioxide. Her approach involves using both observations and models. Here’s an interesting point: observations are also uncertain! Observations of the distant past must be got at through ‘proxies’ – for example, by looking at the type of shells from ocean-dwelling creatures found in sediments on the sea bed. Even observations of the present day are uncertain (although much less so). This is annoying, because it means there is no single ‘true’ state of the climate system, even today! One of the great skills of a good scientist is deriving useful information from a fusion of a variety of uncertain sources of data.

Finally, Paul Williams (University of Reading) showed us the power of random noise. Technically, random processes are called ‘stochastic’ processes. This basically means adding some random variation into models. Think back to the aerosol example. Aerosols are tiny. Imagine trying to calculate how many aerosol particles fall out of the atmosphere per second. That’s an impossibly complicated calculation. Climate models calculate things on the scales of hundreds of kilometres, so they can’t tell us much about what happens to particles thousands of times smaller unless we make some assumptions about how they behave. The atmosphere is very turbulent, so the upwards and downward motions can happen on small scales. For example, at one point a building might be forcing upward motion, but move 10 metres away and the motion might be downwards. Climate models can’t capture this. But what we can do is try to represent it. We can think: ‘Turbulence looks pretty random. What if we just take the vertical velocity calculated by our model and add a number to it – a random number?’. It turns out that helps our models look like the real world.

Of course, we have to tell the model what range to pick its random numbers from, otherwise it could change things too much. But we could make it alter the vertical motion by, say a few millimetres per second. Paul’s work shows this kind of behaviour very much helps. Even when processes in the atmosphere aren’t actually random, they behave like they are random, so we can pretend they are for the purposes of our prediction.

Paul’s work shows how counter-intuitive some climate science is. Who would have thought making models a bit more random would help them become more realistic? It’s some out-of-the-box thinking which might help us understand and use uncertainty better in the future.


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(In)effective counter-arguments

BBC3’s ‘Free Speech’ presenter Jake Humphreys. (C) BBC

Watching BBC3’s Free Speech programme tonight, I noticed an excellent example of a hollow debate in which two sides argue two completely different issues. Their positions reflect their cultural biases. The discussion was about a campaign asking the editor of the Sun newspaper to stop printing pictures of topless women (the infamous ‘Page 3’). The two sides can be (very roughly) summarised thus:

Position 1: The Sun is a mainstream newspaper and printing photographs of topless women perpetuates a culture in which women are measured against their physical attributes. Looking good naked is inconsequential and women should be valued for their intellectual achievements.

Position 2: Women are free to make money selling photographs of themselves in whatever state of undress they like. If some people do not like this, they can express their disapproval by simply not buying the newspaper.

These two positions are clearly in opposition, but one is not a counter-argument to the other. In the programme these two viewpoints were expressed repeatedly and yet no one directly addressed either argument.

Nothing is ever debated

Position 1 argues that the cultural message of printing these pictures in a mainstream newspaper is not one we want to encourage. It does not argue that erotic photographs are wrong, or women who pose for these photographs are exploited victims. To rebut this argument one must argue against the contention that these images foster gender-discriminatory attitudes that have no place in our society.

Position 2 takes a classic ‘freedom’ stance: women should be free to do what they like, as should the newspaper-buying public. To rebut this argument one must either rebut the case for this type of freedom (quite a difficult task) or rebut the contention that Page 3 is a problem because people take offence (easier). Position 1 nearly does it. It points out that Page 3 can be damaging to people who never even pick up a copy of the Sun, because it perpetuates attitudes towards women which contribute to continued gender inequality (highly visible in the gender pay gap).

By my analysis, one can rebut Position 2 by identifying the values behind the argument. Those who subscribe to Position 2 are likely to think their opponents are against personal freedom, whereas it is clear from Position 1 that that is not what their opponents are arguing. Those arguing from Position 1 should Position 2 and explain that, though nothing in the argument is incorrect, there are other reasons why we should campaign to stop the printing of images of nude women in a mainstream newspaper.

Climate science debates are climate policy debates in disguise

This may seem tangential to the main theme of this blog, but I see parallels here with ‘debates’ on climate change and climate policy. Many who argue irrationally against the basic physical science of climate change do so because of their cultural biases against climate policies. Those who value industry, consumer goods and wealth are unlikely to accept necessarily anti-consumptive policies to reduce greenhouse gas emissions. People take positions on one topic but in fact argue from deeply entrenched but irrelevant positions on another. In order to understand arguments one must understand the underlying cultural biases.

Understanding cultural bias both helps people to construct stronger arguments and helps people to rebut them. In other words, it makes debate more robust, and (hopefully) helps us converge on an appropriate course of action. And yet people seem completely unaware of the values systems underlying different arguments on climate, include their own. Dan Kahan makes this point eloquently in his paper as part of the Cultural Cognition Project.