Risk assessment of the global crop loss in ENSO events

Abstract

The uncertainty associated with predicting extreme weather events has serious implications for the world, owing to the greater vulnerability to such events. Continual exposure to unanticipated extreme events is a contributing factor for the global crop loss. Therefore, accurate risk assessment of the global staple crop loss in ENSO events is indispensable to ensure global food security under climate change. In the study, the risk of crop loss is assessed at a global scale considering three factors: the crop yield reduction rate, its coefficient of variation (CV), and the crop reduction probability, based on which a crop loss risk index (RI) was developed and calculated. The results suggest wheat in Canada, Brazil, eastern Europe, Morocco, South Africa, and Australia, and corn in central and southern African countries are at high risk of crop loss with a RI > 1.70 in both El Niño and La Niña events. Rice in the USA, Egypt, and southeast Asia is at low risk in ENSO events with a RI < 0.70. Wheat in Argentina, India, Poland, and Egypt, and corn and soybean in Brazil and China are at high to medium risk in El Niño but at low risk in La Niña events. Wheat in western European countries (France and Germany) and Ethiopia, and corn and soybean in the USA are at low risk in El Niño, but at medium to high risk in La Niña events. In general, wheat, soybean, and rice are at higher risk in El Niño, whereas corn exhibits the opposite trend—it is at higher risk in La Niña events. Wheat is the most vulnerable of the four studied crops to ENSO events. Soybean is at higher risk in El Niño than corn, but corn is at higher risk in La Niña than soybean. Rice is at far lower risk than the other three staple crops in ENSO events, especially in La Niña.