How Simultaneous Crop Failures Threaten Global Food Security

Extreme weather events like prolonged droughts, heatwaves, and heavy rainfall can lead to poor or failure in crop harvest. 

As the planet warms, extreme weather events will increase in frequency and magnitude.

Scientists are concerned that climate change’s effects on crop failure are underestimated, particularly simultaneous crop failures occurring in multiple food-producing regions known as “breadbaskets” of the world because of increasing GHG emissions. Crop failures or declining yields can threaten global food supplies and raise prices.

Research published in Nature Communications, led by climate scientist Kai Kornhuber from Columbia University’s Lamont-Doherty Earth Observatory, highlights factors that led to low crop yields in many breadbasket regions happening at the same time.

The simultaneous intense heat that gripped large parts of the Northern Hemisphere made this a summer of extremes and caused significant damage to people’s health and the environment. China recorded 52.2 °C on 16 July, a new national daily temperature. The month has also broken several significant records from extreme weather events, including heatwaves in Europe, North America, Asia and wildfires in Canada and Greece.

The above examples of compounded events often result in much more significant consequences than when each disaster happens in isolation. Interacting effects increase existing vulnerabilities, putting additional pressure on disaster preparedness and response measures. These simultaneous extremes are also problematic as they could lead to harvest failures in many food-producing regions.

The authors also set out to study the impact of meandering jet streams – the air currents that drive weather patterns in these critical crop-producing countries. According to the study, the jet stream’s effects on the climate and crop yields have remained uncertain. 

Researchers have found that a “strong meandering” of the jet stream, flowing in a large wave shape, produces weather anomalies in significant food-growing regions in North America, Eastern Europe and East Asia and could signal a “synchronized” harvest collapse in the future. The study finds that jet streams could reduce harvest by up to seven per cent and have been responsible for past crop failures.

“Our study reveals that current climate risk assessments may be overlooking sectors and regions at high risk from the complex interactions of several extremes, often linked to dynamical mechanisms in the atmosphere and climate change. This highlights the pressing need for more empirical and process-based research to improve models relating to both climate and agriculture,” writes Dr Kai Kornhubar, lead author of the study (Kornhuber, 2023).

Read the study more by clicking the link in the “Source” section below.