Abstract:

The southwestern region of China contributes more than 50% of the nation’s total tobacco (Nicotiana tabacum L.) production. Consequently, climate change impacts in this region pose significant risks to tobacco cultivation and production, both domestically and globally. Based on tobacco growing stage and yield observation data from 11 agro−meteorological stations in southwest China from 2016 to 2023, a sensitivity analysis and simulation validation of tobacco growth and yield was conducted by using the WOrld FOod Studies (WOFOST) model. After model validation, the calibrated WOFOST mode was combined with 5 General Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under 3 Shared Socioeconomic Pathways (SSP245, SSP370 and SSP585). This framework was employed to analyze extreme hazards during the tobacco growing days and to project future changes in tobacco yield and phenology across southwest China for the period 2030–2100 at a spatial resolution of 0.25°×0.25°. The results provided a scientific foundation for adaptive strategies in tobacco cultivation and production under climate change. The results showed that: (1) the WOFOST model exhibited strong performance in simulating the tobacco phenology and yield across southwest China, with normalized root mean square error (NRMSE) values ranging from 11% to 14%. (2) From 2030 to 2100 in the future, tobacco yield and growing days were projected to experience a declining trend. The higher the emission scenario, the more pronounced the reduction in both yield and growing seasons. By the end of the 21^st century, tobacco yield and growing days were projected to decline by 3.67%−7.24% and 4.66%−7.78%, respectively, while the associated uncertainties increase over time. The reduction region of yield was concentrated primarily in Yunnan province. (3) With increasing emission scenarios, the correlation between extreme meteorological indicators and the tobacco yield and growing days strengthen, particularly for temperature−related extremes, which exhibited stronger positive or negative correlations than precipitation−related indices. Moreover, the frequency of extreme meteorological events is projected to rise more rapidly in Yunnan than in Guizhou and Sichuan, suggesting that tobacco cultivation in Yunnan may face higher climatic risks in the future.

Key words: Tobacco, Crop model, Sensitivity analysis, Climate change, Extreme hazards