Climate change has increasingly become a significant challenge to sustainable socio-economic development, and climate adaptation is a key issue that relevant research focuses on regional sustainable development models. By employing panel data between 2007 and 2020 from 284 Chinese prefecture-level cities, this study adopts quasi-experimental methods, including a difference-in-differences design and double dual machine learning model, to study the impact of climate adaptability on green regional sustainable development. Empirical results confirm that the pilot policy of building climate-resilient cities significantly improves urban green total-factor productivity. Difference-in-difference models (derived from entropy-weight and propensity score matching) and double dual learning models also support the improving effect of regional green total-factor productivity after policy intervention. The digital economy has strengthened the green development effect of pilot policies for building climate-adaptive cities. In addition, policy interventions to build climate-adaptive cities promote green urban development by optimizing industrial development structures and enhancing economic growth resilience. In addition, climate adaptability can also attract highly skilled talent and high-quality enterprises, facilitate science and technological progress in urban areas, and thus promoting the green development of cities in China. This study objectively evaluates the effects of climate policies and provides insights for global adaptation to climate change and optimization of public policies.

Objectives: This paper investigates the role of digital finance in promoting environmental sustainability within a group of 52 developing economies from 2010 to 2019. Specifically, it examines whether digital finance effectively contributes reducing CO₂ emissions in these nations. Methods: This paper is a quantitative study which employs the IV-GMM (instrumental variable generalized methods of moment) approach that tackles any potential endogeneity. Furthermore, to ensure robustness of results, this paper also utilizes different measures of financial development. Results: Estimation results from this study reveal the presence of inverted U-shaped relationship between digital finance and CO₂ emissions. This suggests that the beneficial effects of digital finance may take time to materialize. Additionally, this research also records the presence of the Environmental Kuznets Curve and a significant impact of renewable energy, trade openness, financial development, urbanization, and population on CO₂ emissions. Conclusions: It can be concluded that it may take time for digital finance to become beneficial to the environment. Therefore, in addition to digital finance, countries should also adopt other measures simultaneously (use of renewable energy, combination between digital finance and financial development).