From corn chips to tofu, climate change is messing with the menu.

A new global study led by the University of British Columbia shows that hotter and drier conditions are making food production more unstable, with crop yields fluctuating more sharply from year to year.

For some, it may mean pricier burgers; for others, it can bring financial strain and hunger.

Published today in Science Advances, the study is the first to show at a global scale how climate change is affecting yield swings of three of the world’s most important food crops: corn, soybean and sorghum.

For every degree of warming, year-to-year variability in yields rises by seven per cent for corn, 19 per cent for soybeans and 10 per cent for sorghum.

While previous research has focused on climate-driven declines in average yields, this study highlights a compounding danger: instability.

For many farmers, those swings aren’t abstract. They’re the difference between getting by and going under.

“Farmers and the societies they feed don’t live off of averages—they generally live off of what they harvest each year,” said Dr. Jonathan Proctor, an assistant professor at UBC’s faculty of land and food systems and the study’s lead author. “A big shock in one bad year can mean real hardship, especially in places without sufficient access to crop insurance or food storage.”

Boom, Bust, Repeat Cycle as Crop Yields Become More Unstable

While average yields may not plummet overnight, as year-to-year swings grow, so does the chance of ‘once-in-a-century’ crop failures, or very poor harvests.

At just two degrees of warming above the present climate, soybean crop failures that once struck once every 100 years would happen every 25 years. Corn failures would go from once a century to every 49 years, and sorghum failures to every 54 years.

If emissions continue to grow, soybean failures could hit as often as every eight years by 2100.

Some of the regions most at risk are also the least equipped to cope, including parts of Sub-Saharan Africa, Central America and South Asia, where many farms rely heavily on rainfall and have limited financial safety nets.

Read the full article about crop yield fluctuations by Sachi Wickramasinghe at UBC News.