Drought and Heat Are More Damaging to Food Production Than Floods and Frost

With climate change promising to continue to make extreme weather events more regular occurrences, many agricultural researchers are looking at how tomorrow’s natural disasters might affect the global food supply chain. Until Wednesday, however, researchers did not have a thorough understanding of how the weather has disrupted past harvests. Now, a paper published in the journal Nature shows how 2,800 weather disasters that occurred between 1864 and 2007 affected yields of 16 cereal crops in 177 countries.

The research shows that drought and high heat resulted in the largest loss of crops, with such disasters causing an average drop in national production of 9 to 10 percent. When looking at yield numbers from the United Nations and cross-referencing them with global weather records, the researchers “could not identify an effect from floods and extreme cold.” That finding seems odd in light of the crop-yield damages caused by past floods, such as when historically high waters washed across the American corn belt in 1993, cutting corn production by nearly 30 percent.

While that 10 percent loss is a dramatic number, the decline in yields can be 8 to 11 percent higher in some countries, according to the study. Both the disparity and the regions where the losses were dramatically higher—namely, the developed world—surprised the researchers.

The bigger hit experienced by farmers in a country like the United States versus, say, one in sub-Saharan Africa may be because of the industrial scale of American cereal production. “Across the breadbaskets of North America, for example, the crops and methods of farming are very uniform across huge areas, so if a drought hits in a way that is damaging to those crops, they will all suffer,” Corey Lesk, a coauthor of the paper, told Science Daily.

Forward-looking research suggests that the opposite will be true, with droughts and other climate change–caused weather disasters hitting poorer parts of the world much harder than they will the United States, Europe, and other developed countries. But the resiliency such nations have shown in the past in the face of weather-related disasters may, perhaps, be a silver lining.