Global crop production responses to climate-driven drought under future warming

Climate change has intensified the propagation of drought and the frequency and intensity of extreme weather events, posing severe challenges to global agricultural production and water resource management. However, the synergistic effects of temperature and precipitation, the differential responses of irrigated and rainfed systems, and the role of crop diversity in adaptation strategies remain insufficiently quantified. This study systematically analyzed the propagation mechanisms from meteorological to agricultural drought, quantified the nonlinear impacts of synergistic temperature and precipitation changes on the yields of 16 major global crops, and evaluated the adaptation potential of adjusting irrigated and rainfed areas and crop diversity under future climate change scenarios.First, we employed global gridded datasets and conducted spatiotemporal correlation analyses of the standardized precipitation evapotranspiration index (SPEI) and the standardized soil moisture index (SSI) to elucidate the propagation dynamics from meteorological to agricultural drought. Second, we employed XGBoost machine learning models to quantify the synergistic effects of temperature and precipitation on crop production. The results indicate that moderate warming accompanied by sufficient or increased precipitation exhibits significant positive synergistic effects on multiple crops. However, under higher warming scenarios, this synergy generally shifts to negative, substantially exacerbating production losses. Furthermore, we projected global production of 16 major crops under Shared Socioeconomic Pathway (SSP) scenarios. The findings suggest that by 2100, under high emission scenarios (SSP370 and SSP585), the total production of staple crops such as maize and wheat are projected to decrease (e.g., maize yield declines from approximately 1.15 × 10⁹ tons to about 1.05 × 10⁹ tons), with more pronounced reductions in rainfed areas. In contrast, economic crops such as oilpalm and cassava show increasing trends in global production (e.g., oilpalm production increases to approximately 0.43 × 10⁹ tons and cassava to about 0.4 × 10⁹ tons under SSP585), mainly due to the expansion of rainfed cultivation areas. Finally, we explored the production responses to independent scenario-based adjustments in irrigated and rainfed harvested areas. When both harvested-area variables were increased relative to their 2020 baseline values, crop production increased under favorable climatic conditions; however, this result represents a potential expansion of total harvested area rather than a reallocation between irrigated and rainfed systems. The marginal production gains from these area-adjustment scenarios were substantially constrained under extreme drought and high-temperature conditions. This study provides a robust scientific basis and practical guidance for optimizing agricultural water allocation and adaptive management of irrigated and rainfed systems to mitigate climate risks.