Home / Themes / Human Dimension / Mind over Matter – Climate Change Denial


Cognitive science and psychology can help to explain why there’s a persistent gap between the established facts of climate science and their wider public acceptance. Stephan Lewandowsky and Lorraine Whitmarsh report

This article first appeared in the special March 2014 climate change edition of Geographical magazine.

Every major scientific body in the world, from the UK’s Royal Society to the American Association for the Advancement of Science, endorses the view that greenhouse gas emissions from human economic activity are warming the globe and altering our climate. The US National Academy of Sciences calls climate change a ‘fact’.

Out of more than 14,000 scientific articles on climate change, all but a few dozen accept this consensus position, as do more than 95 out of every 100 climate experts. The latest IPCC report expressed 95 per cent certainty that human activity is responsible for the observed warming during the past few decades.

Case closed?  Within the scientific literature and at scientific conferences, such as the meetings of the American Geophysical Union, the answer is yes. There’s no scientific argument about the fundamentals of human-induced global warming, and the scientific debate has moved on to other, more specific, questions, such as whether or not the current wave of extreme weather events in the Northern Hemisphere might be a consequence of the rapid melting of the Arctic ice cap.


Within the public domain, however, the situation is quite different. Repeated polling has revealed that, at least in Anglophone countries, there’s widespread public scepticism about the reality of global warming and, in particular, about whether or not it’s caused by human activity. How can we explain this divergence between scientific consensus and public doubt?

On the ‘supply’ side, recent research by sociologist Robert Brulle has suggested that nearly US$1billion is spent annually by conservative foundations and think tanks in the USA to support a ‘counter movement’. This movement seeks to reframe public discourse surrounding climate change from one of overwhelming scientific consensus to one of doubt, debate and uncertainty.

Several historical and sociological analyses of the movement have noted the striking parallels to earlier efforts to question well-established scientific findings, such as the link between tobacco and lung cancer, or other public-health findings with potential regulatory implications. Those linkages transcend the institutional and personal levels: some current spokespeople of the climate counter movement were engaged in disseminating contrarian information on behalf of the tobacco industry decades ago.


Even relatively small threats of regulation can trigger counter movements, as revealed by a case involving the makers of aspirin. Aspirin consumption by children with viral illnesses increases the risk of Reye’s syndrome – which is fatal in one third of cases – by 4,000 per cent. When this evidence became known, the aspirin industry’s counter campaign delayed the introduction of warning labels on their products about the risk of Reye’s syndrome by more than five years.

Before the warning labels became mandatory in the USA, some 500 cases of Reye’s syndrome were reported annually; today, less than a handful of cases are reported each year. Those figures highlight the fact that opposition to well- established scientific findings can have ethical and moral implications.

In the context of climate change, those moral implications are driven home by the association between past and present climatic changes and the likelihood of future warfare and civil conflict. As one of us has argued in the academic literature recently, a case can be made that climate disinformation, to the extent that it delays mitigation, may be at least partially responsible for possible future violent conflicts.


Organised counter movements undoubtedly contribute to the public’s uncertainty surrounding climate change by disseminating an alternative narrative and by questioning the findings from climate science. However, no disinformation campaign can succeed without a ‘market’ of consumers willing to buy into it.

So what makes average citizens receptive to disinformation? Why do ‘consumers’ of information resort to dubious internet blogs rather than scientific academies?

A key ingredient to the rejection of scientific findings is the notion of a threat or fear. The public can feel threatened by scientific issues at many levels and for many reasons.

Perhaps most relevant to the rejection of climate change are threats to people’s ‘worldviews’ – that is, the very fundamental beliefs that people hold about how the world should be organised. Worldviews come in many shades and forms, but one prominent distinction – popularised by Dan Kahan at Yale University in Connecticut – is between people whose worldview is ‘hierarchical– individualistic’ and those whose worldview is ‘egalitarian–communitarian.’

Hierarchical–individualistic people (HI) believe that rights, duties, goods and offices in society should be distributed differentially and on the basis of people’s own decisions, without any collective interference or assistance. HI individuals thus tend to support unregulated free-market enterprise and favour charity over social policies.

Egalitarian-communitarian (EC) people, by contrast, believe that rights and goods should be distributed more equally, and that society should bear some responsibility for securing the conditions of individual flourishing. They tend to support redistributive efforts, such as progressive taxation and social safety nets.


Like all binary classifications, the distinction between HI and EC worldviews oversimplifies the complexity of people’s attitudes. Nonetheless, the distinction is powerful enough to predict people’s stance towards numerous scientific issues.

Perhaps not surprisingly, HI individuals are more likely to resist acceptance of climate science than EC individuals – although climate science does nothing more than seek an understanding of how the laws of physics determine our planet’s future, the scientific discoveries to date come with the implication that we need to alter the way we currently do business if we wish to avoid an undue risk to our future. The spectre of business regulation thus looms large, and so do other interventions – such as multilateral agreements – that are anathema to the notion that only individuals, not governments or societies, can determine their own fate.

To control that threat to one’s HI worldview, the laws of physics must be denied. The greenhouse properties of carbon dioxide have been known for 150 years, but those physical facts can’t compete with the need to protect free enterprise from the threats posed by socialism, Communism, Nazism, the Greens, a corrupt IPCC, Greenpeace or the all-powerful solar-energy lobby, to name but a few of the monsters and enemies – many of whom are imaginary – that are brought to life by the peer-reviewed evidence on climate change.


Worldview is an example of a ‘group-level’ identity, but acceptance of climate science – and its denial – are also predicted at the level of individual identities, such as one’s lifestyle. Research shows that how people respond to information about climate change – or other environmental risks – is predicted by whether there are obvious behavioural implications.

Pair information about climate-change risk with a message that we need to cut down on energy use or travel, and people will be more likely to deny the reality or severity of the risk itself. This effect is particularly strong among people who use a lot of energy or travel a lot – in other words, those who have the most to lose by accepting the message.

This kind of ‘motivated reasoning’ is observed for numerous issues, not just climate change. Fundamentally, people don’t like to change what they’re doing, or be told that their favoured behaviours have adverse consequences.

Other research shows that information about climate change is interpreted through a filter of prior attitudes and values. For example, climate ‘sceptics’ don’t become less sceptical when given more information about climate change. Often, their attitudes become more rejectionist.

Existing beliefs determine how the credibility of information is assessed and beliefs tend to be reinforced rather than changed. This pervasive assimilation bias is well established in the psychological literature on social attitudes and poses a challenge for persuading those with entrenched views.


It’s important to recognise how far people are prepared to go when they’re exposed to belief- threatening scientific evidence. In one study, people dismissed the scientific method itself when confronted with threatening information. People will rather declare that an issue can’t be resolved scientifically than accept evidence that is in opposition to their threatened beliefs.

It’s for this reason that climate change deniers often expresses disdain for climate models, proclaiming that ‘real science’ relies on ‘measurements’. In fact, neither measurement nor science can be practised without models.

Cognitive science and psychology can explain why there may be yawning gaps between scientific knowledge and public acceptance of that knowledge. Those gaps necessarily cause frustration to the scientific community, because scientists generally believe that knowledge should trump denial. The historical record seems to affirm that view – the theory of relativity is true despite the denial to which Einstein was subjected, CFCs did cause the ozone hole, HIV does cause AIDS, tobacco really is bad for you and, yes, greenhouse gas emissions do cause climate change.


How can such gaps between scientific knowledge and public acceptance be bridged? There’s much evidence that the acceptance of information can be facilitated if it’s reframed to avoid or minimise threats to people’s worldview. For example, HI individuals are more likely to accept the facts of climate science when the proposed solution involves nuclear power than when it involves emission cuts.

Similarly, the messenger matters. HI individuals are more likely to accept evidence that’s presented by someone clearly identified as hierarchical– individualistic than if the same information is presented by a bearded latte-sipping academic in a Hawaiian shirt. Arnold Schwarzenegger’s strong support for action against climate change is thus of considerable import.

Targeting the appropriate audience is also important. One way of overcoming the assimilation bias – that is, the tendency to filter information so it potentially just reinforces existing attitudes – is to target communication to those who haven’t yet made up their mind. Research shows that these ambivalent or uncertain people are more likely to consider information about the issue with an open mind rather than through their prior-attitudes filter.

One lesson for communicators is not to expend effort trying to convert hardened ‘sceptics’ – which in the UK only account for around 10–15 per cent of the population – but rather to target the ambivalent majority who express uncertainty around impacts (‘How serious is the issue, really?’, ‘Will I really be affected?’) but who haven’t rejected the notion that temperatures are rising and that humans are the primary cause.

Cognitive science has some of the tools needed to understand why people sometimes resist science. It also offers tools that can help to overcome that resistance. Above all, however, what’s needed to manage resistance to climate science among the public is competent political leadership that sketches a clear path to a low-carbon future.

Stephan Lewandowsky is a Professor of Cognitive Psychology at the University of Bristol and was awarded a Discovery Outstanding Researcher Award by the Australian Research Council in 2011. He also received a Wolfson Research Merit Award from the Royal Society in 2013. His research examines the distinction between skepticism and denial and the role of uncertainty in people’s thinking about climate change.

Lorraine Whitmarsh is a Senior Lecturer in Psychology at Cardiff University. Her research examines the psychological and social dimensions of climate change and sustainable behaviour and behaviour change. She also studies the public’s understanding of and engagement with science.