The Effect of Climate Change on Main Areas of Rainfed Wheat Production in Iran

Climate change and global warming has increased climatic unfavorable events that could reduce crop yields and endanger food security. 13 agro-climatic indices which are based on the outputs of CMIP5 models and RCP emission scenarios, were used to investigate the effect of climate change on areas at risk of adverse events. Occurrence probability of heat stresses will be increased during the flowering and grain-filling for early and late cultivars at the end of the century so that these stresses will become the dominant adverse events in all areas. The occurrence probability of at least one adverse event is more than 20 and 90 percent for early and late cultivars, respectively in all areas for the baseline conditions, and this probability is expected to increase by more than 40 and 94 percent for early and late cultivars, respectively under future climate scenarios. Proportional to the reduction of water stress for different emission scenarios, the probability of simultaneous occurrence of heat and water stress at the flowering stage will decrease in future as compared to the baseline. In future, areas where are at risk of at least two adverse event occurrences will increase further, as compare to those where are at risk of at least one adverse event occurrence. Toward the end of the century, more areas will be at risk of at least one and two adverse event occurrences.