A new study has found that the likelihood of extreme temperatures that can affect crop yields has increased significantly in wheat-producing regions of the United States and China.

The results predict that extreme heat waves that used to occur about once every 100 years — most recently in 1981 — are now likely to occur once every 6 years in the Midwestern Wheat Region of the United States and once every 16 years in northeastern China.

In a study published June 2 in the journal Climate and Atmospheric Science, the authors assessed the worst-case scenario in which extreme weather hits two of the world's most important breadbasket regions in the same year, harming global food security through wheat shortages for importing countries.

High heat waves can occur once every 16 years in wheat producing areas in northeast China (Shutterstock)

Stress the global food system

Extreme weather conditions push the winter wheat crop beyond the physiological endurance of plants, so the coincidence of this effect on global wheat regions in multiple regions simultaneously – a possible scenario under recently observed climatic conditions – could strain the global food system in dangerous ways.

According to lead author Erin Koghlan, associate professor of climate science at Tufts University, the study aims to draw the attention of political leaders and decision-makers to the need to respond to this problem by clarifying the degree of vulnerability of the crop, so that they can prepare for the aftermath of the crisis.

Coghlan explained – in a statement to Al Jazeera Net – that one of the problems that hinder the response to such natural crises is the poverty of imagination in terms of visualizing the size of the disaster or expecting the results, and then developing strategies to be followed to face these consequences and build a more flexible response system.

Climate change is disrupting food production worldwide. This year, delays in the rainy season in Henan Province (the largest province of China's wheat province) have complicated grain harvesting efforts that have already been damaged by wet weather.

In the new study, the researchers designed climate models for the U.S. Midwest and northeastern China, then compared the results with the known physiological tolerance of winter wheat grown in those regions.

Extreme heat waves can occur once every 6 years in the U.S. Midwestern wheat producing region (Shutterstock)

Threat Assessment

According to the findings, high temperatures in the spring can slow wheat growth, as well as cause the breakdown of key enzymes within the plant, Coughlan explains. "Physiologically, if a plant is exposed to unprecedented heat waves larger than the events we have seen in the past, it could be devastating for wheat crops."

The study's lead author draws attention to the fact that the findings provide a sound scientific way to assess threats to our food system that fall outside the historical record of known environmental threats.

Although the climate models used in the research did not detect a strong relationship between heat wave patterns in the US Midwest and northeastern China, the researcher stresses that the reason for the seriousness of the problem lies in the fact that these events coincide in China and the United States in the same year, and thus the damage occurs, according to a press release published on the Eurek Alert website.

This synchronization is expected to lead to a gap in wheat availability and, consequently, a global rise in prices as a result of increased demand and supply shortages.

The researchers suggest that we must consider these kinds of threats and the possibility that extreme weather events could lead to more frequent food shocks on a global scale.