Influence of extreme weather disasters on global crop production

Analyses of the effects of extreme weather disasters on global crop production over the past five decades show that drought and extreme heat reduced national cereal production by 9–10%, whereas no discernible effect at the national level was seen for floods and extreme cold; droughts affect yields and the harvested area, whereas extreme heat mainly affects yields. Effects of extreme weather on crop yields This statistical analyses of the effects of extreme weather disasters on global crop yields — derived from country-level agricultural statistics — shows that drought and extreme heat reduced national cereal yields by about 10% over the past five decades. No discernible effect was seen for floods and extreme cold at the national level; droughts affect yields and the harvested area, whereas extreme heat mainly affects yields. In recent years, several extreme weather disasters have partially or completely damaged regional crop production 1 , 2 , 3 , 4 , 5 . While detailed regional accounts of the effects of extreme weather disasters exist, the global scale effects of droughts, floods and extreme temperature on crop production are yet to be quantified. Here we estimate for the first time, to our knowledge, national cereal production losses across the globe resulting from reported extreme weather disasters during 1964–2007. We show that droughts and extreme heat significantly reduced national cereal production by 9–10%, whereas our analysis could not identify an effect from floods and extreme cold in the national data. Analysing the underlying processes, we find that production losses due to droughts were associated with a reduction in both harvested area and yields, whereas extreme heat mainly decreased cereal yields. Furthermore, the results highlight ~7% greater production damage from more recent droughts and 8–11% more damage in developed countries than in developing ones. Our findings may help to guide agricultural priorities in international disaster risk reduction and adaptation efforts.