Study warns food systems face growing risks as hotter, drier conditions hit harvests

Climate change is already reshaping what ends up on global menus, from corn flakes to tofu, as hotter and drier weather triggers sharp swings in food crop yields, according to new research from the University of British Columbia.

The study, published in Science Advances on 6 September 2025, shows that for every degree Celsius of warming, the variability in annual yields rises by 7 per cent for corn, 19 per cent for soybeans, and 10 per cent for sorghum. Unlike earlier studies that emphasised falling averages, the research underscores instability itself as a compounding threat to global food security.

“Farmers and the societies they feed don’t live off of averages, they generally live off of what they harvest each year. A big shock in one bad year can mean real hardship, especially in places without sufficient access to crop insurance or food storage,” said Jonathan Proctor, Lead Author, University of British Columbia.

The analysis points to the intensifying overlap of heat and dryness as the strongest driver of these swings. Hot conditions dry out soil, while parched soil worsens heatwaves, compounding stress on crops. Even brief episodes of such extremes can disrupt pollination, shorten growing seasons and slash yields.

While irrigation can reduce risks where water is accessible, many regions lack the infrastructure or face scarcity. The authors urge investment in climate-resilient crop varieties, better forecasting systems, improved soil management and stronger social safety nets. But they stress that the most reliable solution lies in cutting greenhouse gas emissions driving the warming trend.

“Not everyone grows food, but everyone needs to eat. When harvests become more unstable, everyone will feel it,” Proctor added.