Climate Change Predicted to Cause Significant Wheat Yield Reductions in Africa and South Asia by 2050
Mexico City, Mexico – Leading crop simulation models utilized by a global team of agricultural scientists have revealed alarming projections regarding wheat production and its vulnerability to climate change. According to the research, Africa and South Asia, regions already grappling with food security issues, will experience substantial wheat yield reductions in the coming decades.
The study predicts that global wheat production will decline by 1.9% by mid-century, with the most significant negative impacts expected in Africa and South Asia. The crop simulation models indicate an average decline of 15% in wheat yields across African countries and 16% in South Asian countries by the mid-century mark.
Diego N.L. Pequeno, a wheat crop modeler at the International Maize and Wheat Improvement Center (CIMMYT) and the lead author of the paper, highlighted the previous findings that demonstrated a 5.5% decrease in wheat yields between 1980 and 2010, primarily attributed to rising global temperatures. To assess the impact of climate change on wheat production, the researchers employed multiple models to simulate various scenarios, including the integration of wheat varieties with enhanced heat tolerance, early vigor against late-season drought, and late flowering to ensure normal biomass accumulation. Additionally, the study simulated the use of additional nitrogen fertilizer to maximize the expression of these adaptive traits, world grain reported.
The wheat simulation models employed in the research, namely CROPSIM-CERES, CROPSIM, and Nwheat within the Decision Support System for Agrotechnology Transfer (DSSAT v.4.6), have a broad application in studying diverse cropping systems worldwide, according to Pequeno.
Pequeno explained, “Our study is the first to include combined genetic traits for early vigor, heat tolerance, and late flowering in the wheat simulation. The DSSAT models simulated the elevated CO2 stimulus on wheat growth when N is not limiting.”
Recent variations in wheat yield globally have been attributed to multiple factors such as temperature, water deficit, and water accessibility. The DSSAT wheat models account for these factors by simulating their impact on wheat growth, including heat stress, water balance, drought stress, and nitrogen leaching from heavy rainfall.
Pequeno noted, “Generally, small and low-volume wheat producers suffered large negative impacts due to future climate changes, indicating that less-developed countries may be the most affected.”
While climate change positively impacts wheat grain yield in high latitudes such as France, Germany, and northern China, where warming temperatures extend the early spring growing season, regions at the same latitudes, including Russia and the northwestern United States, will experience warmer temperatures and insufficient rainfall by mid-century, resulting in reduced rainfed wheat yields. These findings challenge the outcomes of some previous studies.
In lower latitudes near the tropics, where temperatures are already warm and insufficient rainfall affects food crops, wheat production will be severely affected by rising heat, leading to significant yield reductions. China, the world’s largest wheat producer, is projected to experience mixed impacts from climate change, but the study reveals an overall 1.2% increase in wheat yields at a national scale.
Pequeno concluded, “Our results showed that adaptive traits could help alleviate climate change impacts on wheat, but responses would vary widely, depending on the growing environment and management practices used.”
The findings emphasize the urgent need for comprehensive strategies to mitigate the detrimental effects of climate change on wheat production, especially in vulnerable regions like Africa and South Asia, where food security concerns are already prevalent.