Global climate change is the largest existential threat of our time. Glaciers are retreating, sea levels are rising, extreme weather is intensifying and the last four years have been the hottest on record (NASA, 2020; World Meteorological Organization, 2020). Although climate change is already significantly impacting natural and human systems around the world, mitigating further and potentially disastrous climate change will require large-scale individual and collective action, including public support for mitigation policies, as well as the more rapid development and implementation of adaptation plans (van der Linden et al., 2015; Pearson et al., 2016).

The behavioral sciences were there at the beginning of the systematic study of climate change. However, in the ensuing quarter century, they largely faded from view, during which time public discourse and policy evolved without them. That disengagement and the recent reengagement suggest lessons for the future role of the behavioral sciences in climate science and policy. Looking forward, the greatest promise lies in projects that make behavioral science integral to climate science by: (1) translating behavioral results into the quantitative estimates that climate analyses need; (2) making climate research more relevant to climate-related decisions; and (3) treating the analytical process as a behavioral enterprise, potentially subject to imperfection and improvement. Such collaborations could afford the behavioral sciences more central roles in setting climate-related policies, as well as implementing them. They require, and may motivate, changes in academic priorities.

Five experiments are reported to compare models of attitude formation about hot-button policy issues like climate change. In broad strokes, the deficit model states that incorrect opinions are a result of a lack of information, while the cultural cognition model states that opinions are formed to maximize congruence with the group that one affiliates with. The community of knowledge hypothesis takes an integrative position. It states that opinions are based on perceived knowledge, but that perceptions are partly determined by the knowledge that sits in the heads of others in the community. We use the fact that people's sense of understanding is affected by knowledge of others’ understanding to arbitrate among these views in the domain of public policy. In all experiments (N = 1767), we find that the contagious sense of understanding is nonpartisan and robust to experimental manipulations intended to eliminate it. While ideology clearly affects people's attitudes, sense of understanding does as well, but level of actual knowledge does not. And the extent to which people overestimate their own knowledge partly determines the extremity of their position. The pattern of results is most consistent with the community of knowledge hypothesis. Implications for climate policy are considered.

Reducing global warming will require enacting strong climate policies, which is unlikely to happen without public support. While prior research has identified varied predictors of climate change policy support, it is unclear which predictors are strongest for the American electorate as a whole, and which predictors are strongest for Democrats and Republicans. In a nationally representative sample of registered voters (n = 2063), we use relative weight analysis to identify the strongest predictors of public climate policy support. We find that, among registered voters in the USA, the five most important predictors of climate policy support are: worry about global warming; risk perceptions; certainty that global warming is happening; belief that global warming is human-caused; and general affect toward global warming. Collectively, these five variables account for 51% of the variance in policy support. Results split by political party indicate that pro-climate injunctive norms and global warming risk perceptions are the variables that differ most between Republicans and Democrats, accounting for significantly more variance in policy support among Republicans. These findings can inform policymakers and advocates seeking to build public support for climate action.

What are the roles of bottom-up and top-down signals in the formation of climate change policy preferences? Using a large sample of American residents (n = 1520) and combining an experimental manipulation of descriptive social norms with two choice experiments, we investigate the effects of descriptive norms and policy endorsements by key political actors on climate policy support. We study these questions in two areas considered to be central in a number of decarbonization pathways: the phase-out of fossil fuel-powered cars and the deployment of carbon capture and storage. Our study provides two important results. First, social norm interventions may be no silver bullet for increasing citizens’ support for ambitious climate policies. In fact, we not only find that climate policy support is unaffected by norm messages communicating an increased diffusion of pro-environmental behaviors, but also that norm messages communicating the prevalence of non-sustainable behaviors decrease policy support. Second, in the presence of policy endorsements by political parties, citizens’ trust in these parties influences their support for climate policies. This study contributes to research in behavioral climate policy by examining the impact of descriptive norms and elite cues on climate policy support.

We argue that the behavioral challenges posed by climate change are fundamentally problems of social influence. Behaviors that perpetuate climate change are often opaque in their consequences; thus, we look to others to infer how to act. Yet unsustainable behaviors, like driving and eating meat, are often the norm; conformity to such norms is a major hurdle to a more sustainable world. Nonetheless, we argue that social norms can also be a powerful lever for positive change. Drawing on two streams of recent research, we show that well-implemented social norm strategies can motivate positive steps even in the face of a negative current norm and even in individuals’ private behavior absent the judgment of others. First, appeals to dynamic norms – information about change in others or trends in norms over time – can lead people to conform to the change itself, even if this change violates current norms. Second, framing normative appeals in terms of an invitation to work with others toward a common goal can increase the motivation to join in. Despite ubiquitous unsustainable norms, careful theory-based representations of social norms can help us make progress on climate change.

Although the need for urgent climate change action is clear, insights about how to make better climate risk management decisions are limited. While significant attention from behavioral researchers has focused on choice architecture, we argue that many of the contexts for addressing climate risks require increased attention to the needs of a deliberative and dynamic choice environment. A key facet of this kind of decision is the need for decision-makers and stakeholders to identify and balance conflicting economic, social and environmental objectives. This recognition of difficult, context-specific trade-offs highlights the need for structuring the decision-making process so that objectives are clearly articulated and prioritized. Equally, policy analyses and deliberations must effectively link priorities with climate risk management options. This restructuring of decision-making about climate change calls for more than a nudge. Scientific and technical efforts must be redirected to help stakeholders and decision-makers better understand the diverse implications of climate change management alternatives and to become better equipped to take actions commensurate with the urgency of the problem.

Citizen activists play a role in translating public concern about the climate crisis to policymakers and elevating it on the political agenda. We consider the dynamic between citizen activists and the decision-makers they seek to influence and we review psychological research relevant to advocating for climate legislation. We conducted a study with citizen activists who lobby the US Congress for a carbon pricing policy to address climate change. The study assessed how activists think about four social psychological approaches: affirmation, social norms, legacy and immediacy. The findings provide a window into activists’ intuitions about which strategies to use, whom to use them with and their perceived effectiveness. A strategy of establishing shared values and common ground (affirmation) was used most frequently overall. A strategy emphasizing the long-term costs and benefits of addressing climate change (legacy) was employed less frequently than affirmation and seen as less effective by activists but it was the only strategy that was associated with perceived increases in Congressional Representatives’ support of the policy. Citizen activists and their interactions with elected officials provide an opportunity for social-behavioral scientists to understand and potentially overcome barriers to enacting climate policy.