Warming Climate Is Making Corn, Soy and Sorghum Harvests More Unstable — Everyone Will Feel the Impact

Warming climate is increasing the risk of widespread crop failures

A University of British Columbia–led study finds that hotter, drier conditions driven by rising global temperatures are making crop failures for three major staples—corn, soybeans and sorghum—more frequent and unpredictable.

The researchers measured year-to-year yield variability and found that each extra degree of warming increases swings in annual harvests. Estimated increases in yield variability are about 7% for corn, 10% for sorghum and roughly 19% for soybeans.

Events once considered once-in-a-century failures are becoming more common. At current warming rates, a 2°C global temperature rise would shift soybean failures that were previously centennial events to roughly once every 25 years; if warming continues unchecked, those failures could occur about every eight years by 2100.

Such simultaneous or regional crop collapses can have serious consequences: rising food prices, local shortages and an elevated risk of famine in vulnerable areas. Low-income regions that depend on rainfall—especially parts of Sub-Saharan Africa, Central America and South Asia—are particularly exposed because they often lack irrigation, insurance, storage and other buffers. However, wealthier regions are not immune to increasing instability in harvests.

Dr. Jonathan Proctor, lead author: When harvests become more unstable, everyone will feel it. Farmers and the societies they feed generally live off what they harvest each year; a big shock in one bad year can mean real hardship, especially where crop insurance or food storage are limited.

Because reduced rainfall and hotter, drier conditions are the primary drivers of these failures, access to irrigation can determine whether a field succeeds or fails in a given season. The authors call for urgent actions to reduce vulnerability and improve resilience.

Recommended responses

• Invest in drought- and heat-tolerant crop varieties and diversified cropping systems.
• Expand irrigation where sustainable and feasible, and improve water management.
• Strengthen weather forecasting, early warning systems, crop insurance and food storage infrastructure.
• Tackle the root cause by reducing greenhouse gas emissions to limit further warming.

Timely policy support and international cooperation will be essential to protect farmers, stabilize supplies and limit the wider social and economic impacts of more frequent crop failures.