Lecture in the course "Climate Change B: Dealing with Climate Change Deniers" — Block: Psychological and Social Backgrounds. This is Lecture 2 of the series; an introduction to climate change was assumed.
In this unit I explain in accessible terms which basic psychological and social mechanisms contribute to denial or skepticism regarding human-caused climate change. I base this on the state of scientific research and on overview findings about the scientific consensus.
First, an overview: The scientific consensus that the recent warming has been predominantly caused by human activities is documented in comprehensive assessments (notably by the Intergovernmental Panel on Climate Change, IPCC) and confirmed by analyses of the scientific literature (see IPCC 2021; Oreskes 2004; Cook et al. 2013). Nevertheless, some people continue to hold the belief that climate change is not real or not human-caused. This contradiction cannot be explained solely as a "lack of facts"; it has several psychological and social causes.
A useful analogy: Information enters our thinking like light through a lens. The lens consists of our values, our identity, our group attachments and our prior beliefs. The same light (the same fact) can appear very different through different lenses. Three central mechanisms that shape these lenses are:
1) Motivated reasoning and confirmation bias: People tend to process information in ways that confirm existing beliefs and to downplay contradictory information. In research this pattern is often summarized under the term "motivated reasoning" (Kunda 1990). A simple example: Someone whose professional or financial interests depend on fossil fuels is more likely to regard studies that cast doubt on human responsibility as credible than studies that support it.
2) Cognitive dissonance: When new information conflicts with beliefs that touch on important aspects of self-view or lifestyle (e.g., "I care about the environment, but my job/my standard of living depends on certain practices"), uncomfortable tension arises — cognitive dissonance. One way to reduce this tension is to question or reject the threatening information (Festinger 1957).
3) Social identity and group membership: Attitudes often align with those of the social groups people feel they belong to. If a social group (political party, occupational group, community) shows skepticism toward climate science, that strengthens the resistance of individual group members to contradictory information. This mechanism is central in theories of social identity (Tajfel & Turner 1979) and explains why facts alone are often insufficient to change opinions.
Finally, external factors influence the spread and consolidation of skepticism: organized misinformation campaigns, certain patterns in media coverage and social media, and elements of conspiratorial thinking. Historical and documented analyses show that targeted campaigns (e.g., against scientific findings) can strongly shape public debate (Oreskes & Conway describe these dynamics historically and documentarily; see sources).
In summary: Denial or strong skepticism about climate change is multi-causal — it arises from interactions between cognitive mechanisms (motivated reasoning, dissonance), social processes (identity, group pressure) and external information supply (media, misinformation).
Now we systematically address central technical terms and findings and link them to empirical studies and reviews.
Scientific consensus
The term here denotes the agreement of the expert community on a matter. The major syntheses of the Intergovernmental Panel on Climate Change (IPCC) and systematic evaluations of the scientific literature show that the overwhelming majority of climate scientists see a strong human contribution to recent warming (IPCC 2021; Oreskes 2004; Cook et al. 2013). These consensus findings are relevant because perceptions of consensus can influence public risk perception and support for measures.
Motivated reasoning
Motivated reasoning is the tendency to select and interpret information in ways that support desired conclusions. Kunda (1990) summarizes the psychological mechanisms in a classic review: People engage in selective memory, selective belief updating, and biased evaluation of evidence. Motivated reasoning is not merely "malicious" — it is a normal cognitive mechanism observed in many contexts.
Cognitive dissonance
Festinger's theory (1957) describes how people experience internal tension when they hold contradictory cognitions at the same time. To reduce dissonance, people either change beliefs, behavior or the evaluation of information. In climate topics this can mean that people downplay climate change or relativize the relevance of their personal contributions, instead of accepting a transformative lifestyle change.
Social identity and group-based motives
According to social identity theory (Tajfel & Turner 1979) people derive part of their self-esteem from group memberships. Attitudes shared by the group are internalized because they foster belonging and social cohesion. Research repeatedly shows that political and cultural affiliations are strong predictors of climate change attitudes: people orient themselves toward the norms of their reference groups.
Political worldview and system justification
Theories of ideological motivations (e.g., Jost et al. 2003) explain why conservative worldviews can be associated with greater skepticism toward interventions in the existing system (e.g., regulation, redistribution). If measures against climate change are interpreted as an attack on existing economic or social orders, this fosters resistance to the scientific message.
Cultural cognition and perceptual filters
Concepts like "cultural cognition" (in communication and risk research) describe how cultural values guide interpretation of risks: people are more likely to accept risks as real when the measures implied by them are compatible with their cultural values. This explains why the same scientific finding is received differently by different groups (see Kahan 2012 as an overview of these mechanisms).
Misinformation, conspiratorial thinking and the persistent influence of false information
Research on misinformation shows two important points: First, false information can often spread quickly; second, its influence can partly persist even after it has been factually corrected — a phenomenon called the "continued influence" effect (Lewandowsky et al. 2012). Additionally, conspiratorial tendencies and distrustful worldviews contribute to rejecting scientific results (Lewandowsky, Gignac & Oberauer 2013).
Empirical findings summarized briefly
- The scientific consensus is well documented (IPCC 2021; Oreskes 2004; Cook et al. 2013).
- Psychological mechanisms such as motivated reasoning and dissonance contribute to rejection (Kunda 1990; Festinger 1957).
- Social identities and political/ideological attachments structure perceptions and are strong predictors of opinions (Tajfel & Turner 1979; Jost et al. 2003; Kahan 2012).
- Misinformation and conspiratorial thinking prolong and reinforce public skepticism (Lewandowsky et al. 2012; Lewandowsky et al. 2013).
In this section I summarize practice-relevant consequences, name limits of the research and suggest two short thought exercises with which you can reflect on what you have learned.
Applications — Guidance for communication and dialogue
Some evidence-based pointers can be derived from the research (summary from the works cited above):
- Emphasize the scientific consensus: perception of consensus can increase acceptance (the consensus findings are well documented by IPCC, Oreskes, Cook et al.).
- Avoid frontal-aggressive approaches against the identity of the interlocutor; direct confrontation can strengthen defensive reactions (mechanisms: motivated reasoning, social identity).
- Contextualize information so that it is compatible with the values of the interlocutor (e.g., emphasize economic opportunities or local agency if that fits their value system).
- Correct misinformation factually and promptly; it is important to offer clear alternative information, because mere negation does not always fully eliminate the "continued influence" (see Lewandowsky et al. 2012).
Limits and uncertainties of the research
- The effectiveness of specific strategies for changing opinions varies greatly by context, target group and medium. Long-term effects are often less well studied than short-term effects. That means: there is no universally effective communication strategy.
- Many studies measure attitudes, not necessarily long-term behavior. Translating changed beliefs into changed actions remains an open challenge.
- Research on misinformation and the effectiveness of corrections is active; some findings (e.g., the assumed "backfire effect") have not always been robustly confirmed in newer meta-analyses. Therefore, findings should be understood as evolving.
Short thought exercises (each 3–5 minutes)
1) Perspective shift: Suppose you are speaking with someone for whom economic stability is the highest good and who is skeptical about climate protection. Formulate in one sentence how you would explain a climate science result so that it takes this person's economic interests into account.
2) Source criticism: Read a short media piece (or headline) about climate. Identify in two sentences which indicators point to possible misinformation or a polarizing presentation (e.g., missing source citation, appeal to anonymous "experts", excessive emphasis on isolated cases instead of overall findings).
These exercises are intended to apply the presented mechanisms: perspective-taking (social identity, value groups) and recognizing information quality (misinformation).