Synergizing green finance and renewable energy development in Belt and Road nations: Illuminating pathways for sustainable growth

Under the current international circumstances, which significantly impact the energy security of all nations, it has become an imperative for countries worldwide to enhance renewable energy development (RE) through the expansion of green finance (GF). Based on a sample dataset comprising 42 countries along the Belt and Road during the period from 2000 to 2022, this study empirically examined the impact of GF on RE. The following conclusions have been derived. (1) There is a significant U-shaped relationship between GF and RE, with an inflection point occurring at 4.8. (2) The threshold test reveals that the relationship between GF and RE exhibits a trend of "strong negative → weak negative → strong positive" as the energy structure evolves. (3) The heterogeneous moderating effect indicates that the positive influence of GF on RE is more pronounced in countries characterized by an early stage of renewable energy adoption and a younger demographic. Additionally, this effect is also stronger in countries with a mature renewable energy sector, political stability, or involvement in the Belt and Road Initiative. (4) The long-term cumulative effects indicate that the adverse influence of GF on RE is relatively constrained, extending approximately up to 6 years. The paper thus proposes to enhance international collaboration in GF, such as engaging in BRI and adhering to international regulations on green development.