Climate change belief systems across political groups in the United States

can empower individuals with the agency to effect change, and help prevent worry from morphing into paralyzing anxiety. Future research needs to investigate the role of efficacy mes- sages in fostering a positive influence of worry within belief systems. Our research also reveals significant changes in the density of climate change belief systems over the past decade, predominantly among individuals without political affiliations. Specifi- cally, people without political affiliations have experienced a significant increase in density, in contrast to politically affiliated groups, which have largely maintained steady density levels. This pattern is echoed in intra-group comparisons. The increase in density, particularly among politically unaffiliated individuals, represents heterogeneities of belief systems within this group across time, contrasting with the relative unchanging structures amongst their polit- ically affiliated peers over the same period. The findings about density align with previous studies suggesting that those less engaged with U.S. politics have less tightly organized belief systems [9]. Our research adds a new dimension to this finding, indicating that those unaffili- ated with a political party have experienced an increase in the organization of their belief sys- tems over time. This development could be influenced by the greater public discourse, expanded awareness, and changes in attitudes toward climate change that have occurred over the past decade [6]. Yet, it remains uncertain which factors specifically contributed to this

change in density among politically unaffiliated individuals. Future research is needed to answer this intriguing question. Interestingly, the inter-group comparisons demonstrate a greater level of structural homo- geneity in belief systems between Republicans and Democrats compared to other group pair- ings, with the exception of the pair comparing Republicans and Independents. This suggests that despite Republicans’ lower levels of pro-climate beliefs and attitudes in comparison to Democrats [6], the underlying structure that governs how individuals from both groups orga- nize their belief systems is not markedly different. This finding implies that bolstering core pro-climate beliefs and attitudes among Republicans could lead to subsequent support for cli- mate change policies and actions, similar to their Democratic counterparts. Indeed, previous findings support this notion by suggesting that effective climate change communication can increase policy support among Republicans [27]. Limitations and future research direction The current study has limitations. First, this study uses cross-sectional survey datasets, not controlled experiments, thus cannot provide causal explanations. This may obscure the causal implications of central belief elements. For instance, it remains unclear whether worry, identi- fied as the central element, is the cause or the consequence of other elements such as risk per- ceptions. Determining the causes of change in a belief system is challenging, as it requires

numerous manipulations and strong assumptions. Nevertheless, theories and empirical evi- dence from experimental research suggest that worry is both a cause and consequence [3] as well as a strong predictor of environmental policy support and behaviors [1, 23]. Therefore, it is important to interpret this study in the context of previous studies to enrich our understand- ing of where climate change beliefs and attitudes fit within a broader psychological system and what the causal directions are. Second, there is a need for future research on effective ways to cultivate a productive level of worry about global warming through communication. Previous research has shown that emphasizing the scientific consensus on climate change does increase worry, but only to a modest degree [3]. An alternative and potentially more effective strategy is ‘worry modeling,’ in which trusted figures explicitly state their concerns about climate change and explain the basis for their worry. This approach holds promise based on social cognitive theory and social PLOS ONE Climate change belief system PLOS ONE | https://doi.org/10.1371/journal.pone.0300048 March 20, 2024 13 / 16