A group of researchers from Australia, Germany, Switzerland, and the USA has
quantified the effect of climate extremes such as drought 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