Investigating the impact of multi-dimensional urbanization and FDI on carbon emissions in the belt and road initiative region: Direct and spillover effects

The climate ambition led by the net zero goal has prompted growing concern among international organizations about the carbon emissions effects of urbanization and foreign direct investment (FDI) in the Belt and Road Initiative (BRI) region. Due to the limited data experiments, the direction and externalities of the impact of urbanization and FDI on carbon emissions in the BRI region remain largely unclear, and accounting for urbanization is also isolated. To address this knowledge gap, this study quantified the direct and spillover effects of multi-dimensional urbanization and FDI on carbon emissions using multiple remote sensing data from 2000 to 2018. The study explored the spatial distribution, evolutionary trends, bivariate evolutionary relationships, and influence mechanisms of carbon emissions with multi-dimensional urbanization and FDI by combining temporal trend (Slope), bivariate spatial autocorrelation, spatial Durbin model (SDM), and other methods. The results indicate that from 2000 to 2018, the total BRI carbon emissions added 253 million tons at an average annual growth rate of 3.68%; since 2013, the average annual growth rate has dropped sharply to 1.34%. East and South Asian countries (especially China and India) posted the highest increase in carbon emissions and had faster growth rates in multi-dimensional urbanization and FDI. Only some European countries, such as France and Germany, achieved overall carbon reduction. The results highlight the adaptability of the “Environmental Kuznets Curve” hypothesis. The “Low-Low” was the main cluster type of the evolutionary trends of carbon emissions associated with each variable. Multi-dimensional urbanization and FDI directly contributed to local carbon emissions, but the effects have gradually weakened over time (except for land urbanization). After controlling for the direct effects, we found a widespread consistently enhanced positive effects of population urbanization and land urbanization on carbon emissions in adjacent areas (especially after the BRI implementation), while FDI reduced the direct impact and strengthened the gain effect on carbon reduction in adjacent regions. Our findings confirm the importance of integrating policies to reduce emissions in population, economy, land, and foreign investment and provide strong evidence for joint governance of carbon emissions among BRI countries.