IntroductionAs the impacts of climate change intensify1,2, research suggests that public responses toward climate policy are shaped by ideological and social divisions3,4, raising questions about how climate action can advance without reinforcing political polarisation. Social science research has indicated that divisions are rooted not in knowledge deficits but in motivated reasoning influenced by cultural worldviews, such as hierarchy and individualism3,5. These worldview-driven biases, often described as “myside bias”, limit the effectiveness of information-based interventions6.Biodiversity conservation may offer a promising avenue. A recent survey in eight countries found over 80% support for the global “30-by-30” target, suggesting that such policies are politically feasible and socially acceptable7. Biodiversity loss is directly intertwined with climate change through cascading feedback, and protecting forests, grasslands, wetlands, coastal ecosystems, and montane ecosystems can enhance carbon sequestration and climate resilience8,9. In contrast, climate mitigation measures such as the expansion of renewable energy infrastructure can raise concerns about land use conflicts and impacts on ecosystems and landscapes10, highlighting the possibility of trade-offs between climate and biodiversity objectives. For example, in countries such as Japan, large-scale ground-mounted solar projects (“mega-solar”) have raised concerns about land conversion and associated ecological impacts11, while wind power development has raised concerns about collision risk and habitat impacts on birds and other wildlife12. Such real-world synergies and trade-offs may shape how different policy approaches are perceived and supported. Treating climate and biodiversity in isolation, in both research and policy, risks overlooking critical synergies and trade-offs13,14. Thus, policies situated within the domain of biodiversity conservation may contribute indirectly to climate mitigation, while being interpreted differently across cultural worldviews compared to policies explicitly associated with climate change.Public acceptance of such measures depends on risk perception, which strongly influences behaviour and policy support15. Building on Cultural Theory16, Cultural Cognition Theory5 posits that individuals’ interpretations of climate change risk information are influenced by two dimensions, individualism–communitarianism and hierarchy–egalitarianism. Individualism–communitarianism reflects orientations toward group living as opposed to individual autonomy, whereas hierarchy–egalitarianism reflects preferences for stratified, as opposed to equal, social relations5. People with individualistic and hierarchical worldviews often downplay environmental risks because acknowledging such risks may be perceived as threatening market autonomy and established authority. Conversely, people with more egalitarian and communitarian perspectives exhibit increased risk perception based on the view that unregulated markets can foster inequality and social harm16,17. Importantly, cultural cognition research suggests that greater scientific knowledge does not necessarily lead to convergence in climate change risk perceptions. Rather than reducing disagreement, higher levels of scientific literacy may enhance individuals’ capacity to selectively interpret evidence in ways that reinforce their cultural worldviews, a process described as identity-protective motivated reasoning3. From this perspective, knowledge may enhance individuals’ ability to defend worldview-consistent interpretations rather than to revise beliefs independently of prior value commitments. Accordingly, scientific knowledge may either reduce or intensify worldview-based differences, depending on how environmental risks are interpreted within specific issue domains. In the present study, general scientific knowledge is therefore included not merely as an informational variable, but as a potential moderator of the relationship between cultural worldviews, risk perception, and policy support. In this context, climate change risks can be understood as a specific form of environmental risk that has become strongly associated with broader political and cultural interpretations3,4,18. Biodiversity-related issues, by contrast, may not yet function as equally salient political or cultural signals, although this possibility remains underexplored.Framing is commonly understood as the selection and salience of particular aspects of an issue in shaping interpretation and evaluation19,20. Prior experimental studies have examined how message framing shapes policy support18,21, but less attention has been given to whether worldview-policy associations differ across environmental issue domains more broadly. In this study, however, we do not experimentally manipulate alternative descriptions of identical policies. Instead, we examine whether associations between cultural worldviews and policy support differ across policy domains, specifically, climate change and biodiversity conservation. Because the policy sets differ in substantive content, this comparison captures domain-based differences in evaluative orientation rather than experimental effects of framing.A key gap is that cultural worldviews, as they are often conceptualised in the social sciences, primarily address orientations toward social organisation and governance, while orientations toward nature are not typically treated as constitutive elements of the worldview itself. In contrast, biodiversity research, particularly through the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) framework, has emphasised diverse values of nature22,23,24,25,26. Specifically, the IPBES framework distinguishes three types of values22,24,26: instrumental values refer to the direct benefits that nature provides to people, such as food, clean water, and economic resources; intrinsic values recognise that nature has worth in its own right, independent of human use; and relational values capture the meaningful relationships between people and nature, including cultural identity, sense of place, and emotional attachment to landscapes. These distinct values have been shown to motivate conservation behaviour in different ways27,28: instrumental values may drive resource management aimed at sustaining ecosystem services, intrinsic values can foster moral commitments to protect species regardless of their utility, and relational values often underpin place-based stewardship rooted in cultural and personal connections to nature. However, their relationship with broader cultural worldviews remains underexplored.In the current study, we investigated how cultural worldviews and values of nature jointly shape risk perception and policy support regarding climate change and biodiversity loss. We analysed data from a nationwide two-wave online survey of 1133 respondents in Japan. We measured cultural worldviews (hierarchy–egalitarianism and individualism–communitarianism), values of nature (intrinsic, instrumental, and relational), general scientific knowledge, risk perceptions related to climate change and biodiversity loss, and support for three categories of policy measures: climate change measures, climate change-related biodiversity conservation measures, and stand-alone biodiversity conservation measures. We first used multiple regression analyses to identify key predictors of risk perception and policy support and then applied piecewise structural equation modelling to test hypothesised pathways linking worldviews, values, knowledge, and policy support across climate and biodiversity domains.Rather than experimentally testing framing effects, this study examines whether associations between cultural worldviews and policy support differ systematically across environmental issue domains. We tested three main propositions. First, we hypothesised that hierarchical and individualistic worldviews would be negatively associated with climate change risk perception and with support for climate change measures. Second, we examined whether the strength of these associations differs across policy domains. Specifically, we assessed whether policies presented within the domain of biodiversity conservation exhibit weaker associations with hierarchical and individualistic worldviews than policies presented explicitly as climate change measures. This distinction concerns differences in policy domain emphasis rather than differences in regulatory intensity. Third, we investigated how cultural worldviews and values of nature jointly relate to environmental risk perceptions and policy support, and whether general scientific knowledge moderates these associations. By integrating cultural worldviews with values of nature across climate and biodiversity policy domains, the present study seeks to clarify how domain context shapes evaluative orientations toward environmental policy.ResultsPredictors selected using multiple regressionWe used multiple regression as an exploratory step to identify relevant predictors of five dependent variables: climate change risk perception, biodiversity loss risk perception, policy support for climate change measures, policy support for stand-alone biodiversity conservation measures, and policy support for climate change-related biodiversity conservation measures. Average support differed significantly across the three policy categories (repeated-measures ANOVA: F(1.57, 1777.64) = 179.63, P