Associations between green space exposure and climate anxiety among Chinese university students: the role of school-based and leisure-time physical activity, nature connectedness, and perceived stress

Background Climate anxiety has become an important mental health concern among young adults, yet the pathways linking green space exposure to climate-related distress remain unclear. This study examined whether objective green space exposure was associated with climate anxiety among Chinese university students through domain-specific physical activity, nature connectedness, and perceived stress. Methods A cross-sectional study included 918 undergraduate students from four universities in Wuhan Province, China. Residential and campus greenness were assessed using the satellite-derived Normalized Difference Vegetation Index (NDVI). Moderate-to-vigorous physical activity (MVPA) was objectively measured using accelerometers and classified as school-based or leisure-time MVPA. Nature connectedness, perceived stress, and climate anxiety were assessed using validated questionnaires. Structural equation modeling with bias-corrected bootstrapping (5,000 resamples) was used to estimate direct and indirect associations while adjusting for relevant covariates. Results Residential greenness was positively associated with leisure-time MVPA and nature connectedness, whereas campus greenness was more strongly associated with school-based MVPA. No significant direct association was observed between residential greenness and climate anxiety after accounting for mediators. However, an inverse indirect association was identified through leisure-time MVPA, nature connectedness, and perceived stress. Leisure-time MVPA showed stronger associations with climate anxiety than school-based MVPA. Nature connectedness displayed a positive direct association with climate anxiety but an inverse indirect association through lower perceived stress. Perceived stress showed the strongest association with climate anxiety. Conclusion These findings suggest that green space may be linked to climate anxiety primarily through behavioral and psychological pathways.