<p>Social polarisation poses a major challenge to collective climate action. In this context, biodiversity conservation, when aligned with climate objectives, may face less worldview-driven resistance than direct climate policies. However, the links between values of nature and wider cultural worldviews remain poorly understood. Here we show, using a nationwide survey (<i>N</i> = 1133) in Japan, how cultural worldviews relate to risk perception and environmental policy support. Individuals with hierarchical worldviews perceived climate change risks as lower and tended to be less supportive of climate change measures than individuals with more egalitarian worldviews. Yet these negative associations were weaker for perceived biodiversity loss risks and for support for climate change-related biodiversity conservation measures, and no direct association was found for stand-alone biodiversity conservation measures. General scientific knowledge was positively associated with support for biodiversity conservation measures, including those related to climate change. These associations between cultural worldviews and policy support differed across climate and biodiversity policy domains.</p>