Assessing climate impacts on crop yields using regional climate models

Climate change has significant impacts on the crop yields. Corn the main crop in U.S., also is the largest source of biofuels. The U.S. accounts for 45% of the world’s corn. The inter-annual corn yield change exerts an important influence on food and energy security. This study examines the impact of climate change on future mean corn yield and corn yield inter-annual variability for corn in the U.S. Corn Belt using regional climate model data, historical agronomic data, and statistical models of yield. Our simulations of historical yield using monthly temperature and precipitation data from RegCM3/NCEP show robust relationships to observed yield. Supposing current corn growing area remains constant, aggregate yields are projected to decrease by 13.8% by the years 2038–2063 relative to the years 1968–1993 due to the effects of climate change. The yield coefficient of variation is projected to increase by 52.4% over these periods. Projections from all five NARCAPP regional climate models examined here show that climate change will cause an increase in the corn yield coefficient of variation and a decrease in the mean yield. Since variability in food and energy supply is a critical concern for food and energy security, these climate-yield results suggest that the climate-induced yield variability should be explored more widely