Climate change and the extreme weather associated with it will be a growing threat to wheat-producing countries in the coming years, according to a study from the Friedman School of Nutrition Science and Policy at Tufts University. The findings were published June 2 in the peer-reviewed research journal Climate and Atmospheric Science.
The study, which predicted that heatwaves would become more frequent worldwide and diminish crop yields, focused on potential scenarios in China, the world’s top wheat producer, and the United States, which ranks fourth.
“Climate change is causing unprecedented events globally, which could exceed critical thresholds and reduce yields, even if there is no historical precedent,” the authors of the study said. “This means that we are likely underestimating climate risks to our food system. In the case of wheat, parts of the United States and China show little historical relationship between yields and temperature, but extreme temperatures are now possible that exceed critical physiological thresholds in wheat plants.”
China currently is being affected by unusually heavy rainfall and high humidity in Henan province, which is impacting millions of tonnes of wheat right before harvest. Meanwhile, the hard red winter wheat crop in the United States is being impacted by a relentless drought, particularly in Kansas, a top wheat producing state, where output is expected to drop by 20% this year.
Using data from 1981, the Tufts University study found that heatwaves that were only likely to happen once a century back then were now likely to happen once every six years in the US Midwest and once every 16 years in northeastern China.
The study noted that high spring temperatures can slow down wheat’s growth and cause key enzymes to break down within the plant.
The researchers concluded that if extreme weather affected multiple regions at once — a scenario possible in today’s climate — it could stress the global food system in dangerous ways.
In addition to the current problems with the China and US wheat crops, Argentina, the largest wheat producer in South America, saw wheat production plummet last year due to extreme drought and Ukraine, a top 10 wheat producer, has seen a significant drop in output and exports since it was invaded by Russia in February 2022.
