Climate Extremes Explain 18%-43% of Global Crop Yield Variations

A group of researchers from Australia, Germany, Switzerland, and the USA has quantified the effect of climate extremes such as droughts or heatwaves on the yield variability of staple crops around the world.

Overall, year-to-year changes in climate factors during the growing season of maize, rice, soy and spring wheat accounted for 20%-49% of yield fluctuations. Climate extremes, such as hot and cold temperature extremes, drought and heavy precipitation, by themselves accounted for 18%-43% of these interannual variations in crop yield.

The researchers used a machine-learning algorithm, Random Forests, to tease out which climate factors played the greatest role in influencing crop yields. They found that the most important climate factors for yield anomalies were related to temperature, not precipitation. The researchers also identified global hotspots – areas that produce a large proportion of the world's crop production, yet are most susceptible to climate variability and extremes. The following hotspots were identified: North America for soy and spring wheat production, Europe for spring wheat, and Asia for rice and maize production.

For more details, read the article in ARC Centre of Excellence for Climate Extremes.