Annual food caloric production is the product of caloric yield, cropping frequency (CF, number of production seasons per year) and cropland area. Existing studies have largely focused on crop yield, whereas how CF responds to climate change remains poorly understood. Here, we evaluate the global climate sensitivity of caloric yields and CF at national scale. We find a robust negative association between warming and both caloric yield and CF. By the 2050s, projected CF increases in cold regions are offset by larger decreases in warm regions, resulting in a net global CF reduction (-4.2 +/- 2.5% in high emission scenario), suggesting that climate-driven decline in CF will exacerbate crop production loss and not provide climate adaptation alone. Although irrigation is effective in offsetting the projected production loss, irrigation areas have to be expanded by >5% in warm regions to fully offset climate-induced production losses by the 2050s. Climate change will impact agriculture, and this study shows cropping frequency and caloric yield are negatively impacted on the global scale by warming. While cold regions will increase cropping frequency, warm regions will see greater decreases, resulting in an overall decline in production.
Zhu, P; Burney, J; Chang, JF; Jin, ZN; Mueller, ND; Xin, QC; Xu, JL; Yu, L; Makowski, D; Ciais, P
Warming reduces global agricultural production by decreasing cropping frequency and yields
Nature Climate Change