Efforts by farmers to adapt to rising temperatures will not be enough to prevent severe losses in global staple crop production due to climate change, according to a new study published in New Scientist on June 18.

The findings suggest that five of the world’s six most important crops will experience major yield declines by the end of the century, with serious implications for global food security.

Relying on one of the largest datasets of its kind, researchers from the University of Illinois Urbana-Champaign analysed crop yield data and weather patterns from 54 countries, focusing on six staple crops that together account for more than two-thirds of global caloric intake. “It’s one of the largest datasets now available of high-resolution crop yields,” said Andrew Hultgren, lead author of the study.

The analysis projected changes in crop productivity under different climate scenarios, while also estimating how farmers might adapt. “We mined that data for information about how farmers have reacted to weather shocks historically,” said Hultgren. This included responses such as switching crop varieties, increasing irrigation, or applying more fertiliser.

Despite these adaptive strategies, the researchers found that rising temperatures will still result in substantial declines in food supply. For every 1°C increase in global temperature, available food per person is expected to decrease by around 121 kilocalories per day. “That works out to giving up breakfast for everyone,” Hultgren said, referring to the likely outcome if the planet follows its current trajectory to hit 2.7C-3.1C by 2100, according to the current models.

Corn is particularly vulnerable. According to the projections, global corn yields will fall by 12% under a moderate emissions scenario and by 28% if emissions remain very high, compared to the base line without climate change. Other crops including wheat, soybeans and barley are similarly at risk.

Rice is the only major staple crop expected to benefit modestly from warming, owing to its improved performance during warmer nights. However, this limited gain is unlikely to offset the broader pattern of losses across the global food system.

The findings underscore the need for both emissions reductions and transformative changes in agricultural systems to mitigate the long-term impact of climate change on food security.