Climate Change Worry and Flourishing Among Chinese University Students: The Roles of Anxiety-Depressive Symptoms and Physical Activity

Background/Objectives: Climate change worry is an emerging concern in youth mental health, but little is known about how it is associated with positive psychological functioning among university students. This study examined whether climate change worry was associated with flourishing and whether this association showed a cross-sectional statistical indirect effect through anxiety and depressive symptoms, with physical activity specified as a first-stage boundary condition. Methods: A cross-sectional anonymous survey was conducted in 2026 using convenience sampling among students from four universities located in three provincial-level regions of China, covering southern, western, and central areas. After predefined quality control procedures, 2826 valid responses were included. Climate change worry, anxiety and depressive symptoms, flourishing, and physical activity were assessed using the Climate Change Worry Scale (CCWS), the Patient Health Questionnaire-4 (PHQ-4), the Flourishing Scale (FS), and the Physical Activity Rating Scale-3 (PARS-3), respectively. Pearson correlations and conditional process analyses were conducted using the PROCESS macro, with 5000 bootstrap samples. Results: Climate change worry was positively associated with anxiety and depressive symptoms (r = 0.331, p < 0.001) and negatively associated with flourishing (r = −0.193, p < 0.001). Anxiety and depressive symptoms were negatively associated with flourishing (r = −0.486, p < 0.001). The cross-sectional statistical indirect effect through anxiety and depressive symptoms was significant (indirect effect = −0.1277, 95% bootstrap CI: [−0.1441, −0.1123]). Physical activity was statistically associated with a weaker first-stage association between climate change worry and anxiety/depressive symptoms (B = −0.0014, p < 0.001; ΔR2 = 0.0064). The index of moderated mediation was significant (0.0014, 95% bootstrap CI: [0.0008, 0.0020]). Conclusions: Climate change worry was statistically associated with lower flourishing, primarily through higher anxiety and depressive symptoms. Physical activity was associated with a weaker first-stage association, but the moderation effect was small in practical magnitude. Given the cross-sectional and self-report design, these findings should be interpreted as conditional statistical associations rather than causal or protective effects.