Climate risk and the production foundations of nutrition security: evidence from grain-supply capacity in Chinese cities

Introduction Climate risk poses growing challenges to food availability and the resilience of urban food systems. Methods Using panel data for 298 prefecture-level cities in China from 2010 to 2023, this study employs a two-way fixed-effects model to examine the impact of climate risk on production-side food security, its transmission mechanisms, and regional heterogeneity. Results The results show that climate risk significantly reduces city-level grain output, and this finding remains robust to alternative specifications and endogeneity treatments. Mechanism analyses indicate that climate risk weakens food availability by adversely affecting agricultural mechanization, effective irrigation, grain-sown area, and fiscal support for agriculture. The negative effect is more pronounced in non-major grain-producing areas and regions with lower adaptive capacity. Further analysis suggests that climate risk also undermines agricultural economic performance and food-supply stability. Discussion These findings provide city-level evidence on how climate shocks affect production-side food security and highlight the importance of strengthening agricultural production conditions and adaptive capacity to enhance food-system resilience and safeguard nutrition security.