Heterogeneous mitigation effects of adaptation initiatives on grain yield losses from extreme temperatures in China: implications for grain resilience and food security

Introduction The increasing frequency of extreme weather events has posed significant challenges to global food security. While it is well established that such events can reduce food production, the specific effects of different types of extreme weather on food security, as well as the heterogeneous mitigation strategies available, remain inadequately understood. Methods This paper systematically analyzes the impacts of extreme high and low temperature events on maize yields using panel data from major maize-producing regions in China from 2000 to 2023, highlighting the potential threats climate extremes pose to food security. Results and discussion The findings reveal that: (1) extreme high temperatures significantly suppress maize yields, with the number of extreme heat days showing a consistent negative effect nationwide and across regional and growth-stage subsamples, particularly pronounced in northern summer maize-producing areas, indicating heat stress as a key constraint on stable grain production and supply; (2) the effects of extreme low temperatures exhibit clear regional heterogeneity, with southern spring-sown maize more vulnerable to late frosts during seedling and nodulation stages, resulting in greater yield losses, whereas in northern regions, low temperatures mostly occur before sowing and have a limited impact; (3) the adverse effects of extreme temperatures have intensified over time, with extreme heat impacts worsening in recent years—reflecting cumulative climate risks and agricultural system vulnerability—while the negative impacts of low temperatures have somewhat diminished since 2010, indicating improved farmer adaptation; (4) agricultural insurance and protected agriculture have significantly mitigated the impacts of extreme low temperatures on maize yields, demonstrating their effectiveness in cold climates, but have yet to provide significant buffering against yield losses from extreme heat, suggesting opportunities to optimize existing insurance mechanisms and protective agricultural technologies. These findings contribute to a deeper understanding of climate adaptation strategies and support the achievement of SDGs 2 (Zero Hunger) and 13 (Climate Action) through enhancing resilience in the agri-food system.