Can urban green space improve carbon emission performance? Double test based on efficiency and spatial economics

At present, the great potential of urban green space (UGS) in adapting to climate change and promoting low-carbon development of society has been underestimated. This study introduces a two-dimensional evaluation framework that assesses the role of UGS in improving carbon emission performance (CEP) from an efficiency perspective and analyzes its spatial effects on CEP from a spatial economics perspective. Using panel data from 282 Chinese cities from 2006 to 2021, this study first compares traditional carbon emission performance (CEP-T) with CEP considering green space (CEP-G) using the Epsilon-based measure model with undesirable outputs (UN-EBM). It then explores the direct effect and spatial spillover effect of UGS on CEP-T through the Spatial Durbin Model (SDM). The results show that: (1) In terms of the efficiency dimension, UGS can effectively improve CEP at the national, regional, and city levels. CEP improved more strongly at the city level than at the regional and national levels, with 280 cities improving their CEP, and southern cities improving more than northern regions. (2) In terms of the spatial economics dimension, UGS can have a positive impact on local CEP improvement. At the same time, UGS also has a spatial spillover effect, transcending urban boundaries to improve the CEP of neighboring areas. In addition, there is heterogeneity in the improvement of UGS on CEP, with stronger effects in the south and weaker effects in the north. These findings provide important implications for policymakers to enhance low-carbon development and address climate change through UGS.