Climate change could have devastating consequences for wheat

Coughlan de Perez and her collaborators run climate models for the Midwest and Northeastern China, then compared the results with known physiological tolerances of the winter wheat grown in those regions.

High spring temperatures can slow down wheat s growth and also cause key enzymes to break down within the plant.

The climate models show that temperatures that were expected to affect the Midwest in 1981 were expected to happen in only 1 out of 100 years, causing the Midwest to experience heat waves every six years. In northeastern China, a 1 in 100-year heat wave is expected to happen every 16 years.

Physiologically, if we get heat waves that are unprecedented and bigger than things we have seen in the past, this can be devastating for wheat crops, Coughlan de Perez said. She added that these two key agricultural areas have never experienced temperatures as high as the climate models say is possible.

places that have not recently experienced an extreme event or disaster are places that probably aren t preparing for one, she said.

The risks to crucial crops are increasing as the world warms, Weston Anderson, an assistant research scientist at the University of Maryland and NASA, said.

The new study offers a solid and sound way to evaluate threats to our food system that are beyond the range of the historical record, he said.

Although the climate models used in the study did not find a strong connection between heat wave patterns in the Midwest and northeastern China, Coughlan de Perez said it's possible that such events could overlap in the same year.

But that would lead to cratering of wheat supply and a rise in prices. In 2022, China produced about 17% of the world's wheat. According to the Department of Agriculture, the U.S. produced about 6% of its crop from the Midwest.

In many nations, wheat imports are critical for food. It became especially clear during the Russian attack on Ukraine early last year, which disrupted wheat exports from both countries. They were mainly responsible for about a third of global wheat exports. In many African and Middle Eastern countries that depend on those wheat sources, prices skyrocketed, causing fears about imminent hunger and starvation. However, the worst consequences of the Wheat crisis were averted when the warring nations reached a deal that allows Ukraine to export grain.

The study is far from the first to warn about climate change's danger to our food supply. The recent U.N. Intergovernmental Panel on Climate Change's synthesis of climate impacts, its sixth such report, predicts that the risk of hunger will increase over time. The various impacts of climate change could hinder the production of staple crops like rice, wheat, soybeans and corn, and the risk of simultaneous crop failures will increase, the report says.

However, other recent studies suggest certain levels of global warming could actually increase overall global wheat yields, Mr. Anderson said. In addition, climate change could shift the regions where wheat can be grown, and higher levels of carbon dioxide could increase photosynthesis and production. Bust years are also becoming more likely, the same studies suggest.

The latest evidence suggests that some growers' efforts to improve wheat breeding may not keep up with the speed of the climate's warming.

We should be considering these kinds of threats and the possibility that extreme climate events are leading to more frequent shocks on a global scale, even for these crops where we expect average yields to be increasing, Mr. Anderson said.