Introduction: To mitigate the global health threat posed by climate change, multifaceted responses are required. As shown in previous work, older, male, and highly educated individuals exhibit greater general readiness to act against climate change; the same is true of people living in larger communities. The present study investigates the relationships between the indicators (facets) of the readiness to act against climate change—namely individual climate-friendly behavior, acceptance of climate-protection policies, and political participation—and relevant sociodemographic factors.Methods: Data from four waves (2022–2023) of the Planetary Health Action Survey (PACE) were analyzed (N = 3,830, nonprobabilistic representative German sample). Sociodemographic variables (e.g., gender, age, and education) and the three abovementioned facets of the readiness to act against climate change were assessed to examine their relationships.Results: Women and older individuals exhibited more climate-friendly behavior and policy acceptance. Political participation showed the opposite trend. Higher education was linked to less sustainable behavior, greater policy acceptance, and higher participation, while municipality size was only linked to the latter two. Additional analyses explore the relations between age and the constructs at the item level.Conclusions: The findings underscore the importance of a nuanced understanding of people’s readiness to act against climate change. There is a need for tailored communication strategies in climate action that consider communication objectives along with audience characteristics. Different target groups may be relevant when campaigners want to increase political participation rather than change individual behaviors. As older individuals exhibit greater readiness to act in some respects, it is important to include young people in climate-communication efforts.