Green perception underlies pro-greenspace behavior, but external stimuli and behavior are not always aligned. Understanding how residents’ perceived external green stimuli influence pro-greenspace behavior, and how the “good citizen” image (face) shapes this relationship, is essential. The study aims to deepen the understanding of the complex mechanisms driving urban residents’ pro-greenspace behavior by constructing an extended Stimulus-Organism-Response theoretical framework (C-SOR) that includes contextual factors. Using data from a 2024 field survey of 959 residents from Shanghai, China, this study employs Ordinary Least Squares (OLS) regression to examine the main effect of green perception on pro-greenspace behavior. A mediation model is employed to analyze the mediating role of nature connectedness, while a moderation model tests the moderating effect of “good citizen” image (face) on the stimulus–behavior relationship. The results show that green perception significantly promotes pro-greenspace behavior, positively influencing it through nature connectedness. However, the “good citizen” image (face) exerts a motivational crowding-out effect on green perception. Further analysis reveals individual heterogeneity in the expression of these effects across different types of pro-greenspace behavior. The findings highlight the importance of green space experience and the activation of environmental wisdom in traditional culture, offering new perspectives for developing strategies to guide pro-greenspace behavior.

Coordinated regional development plays an increasingly important role in promoting low-carbon transitions across China’s urban agglomerations. This study examines the effect of the Beijing–Tianjin–Hebei Coordinated Development Strategy, elevated to major national strategic status in 2014, on urban carbon emissions. Using an unbalanced panel of 294 prefecture-level and higher-level cities from 2010 to 2023, we employ a two-way fixed-effects difference-in-differences model to evaluate the strategy’s overall carbon-mitigation effect, potential transmission pathways, and spatial heterogeneity. The baseline DID coefficient is −0.052, corresponding to a 5.0% decline in city-level total CO₂ emissions in the 13 treated cities relative to the national comparison group after policy implementation. Within the same comparison framework, further analysis documents significant positive post-policy differentials in both the industrial-structure-upgrading index and green invention-patent applications; the industrial-structure-upgrading results are consistent with a potential emissions-reduction pathway. The heterogeneity analysis indicates a statistically significant relative carbon-mitigation effect for the prefecture-level cities of Hebei compared with the national comparison group, with a larger relative effect in Beijing and Tianjin. This spatial pattern is consistent with differences in industrial structure, innovation capacity, and environmental governance capacity across cities. The findings provide city-level quasi-experimental evidence that coordinated regional development can promote urban carbon mitigation and support differentiated carbon governance, coordinated industrial upgrading, and cross-regional low-carbon policy design.