Labor shortage, not land, is the bigger threat to future food security, study finds

"The greatest threat to future food security is not a shortage of farmland — it is a shortage of agricultural labor driven by low birth rates and urbanization."

As low birth rates and the decline of rural communities become an increasingly tangible reality, an international research team that includes South Korean scientists has developed a new data-driven model that incorporates shrinking agricultural workforces into future food security analysis. The findings suggest that in most parts of the world, a lack of farm labor — not land — could become the key constraint on agricultural land use.

KAIST announced Friday that a research team led by Kim Hyung-jun, a professor in the Department of AI Future Studies, collaborated with KAIST's KI for Climate-Environment-Energy Research professors Jeon Hae-won and Niklas Forsell, and Taikan Oki, a professor at the University of Tokyo, to analyze how declining agricultural labor will affect future food production.

Until now, food security and climate change research has largely focused on how much farmland can be secured. Projections were built by calculating whether climate and soil conditions are suitable for farming and how much food demand will grow. Agricultural labor — the human variable — was typically treated as a fixed value or factored in only as a simple measure of population size from a food-demand perspective.

The research team focused on the shrinking of rural populations due to low birth rates and urbanization, and explicitly incorporated into their model the structural pattern by which the agricultural workforce declines as economies develop.

The results were more pronounced than expected. In most regions of the world, the actual area of farmland that can be cultivated will shrink due to agricultural labor shortages, the analysis found. In some areas, the lack of farm workers was found to be a greater constraint than climate or soil conditions.

The team said that even in scenarios where technology advances rapidly, the agricultural labor problem may not be easily resolved. Technological progress does increase the area one person can farm. But as industries grow, more people move into manufacturing and services, accelerating the decline of rural populations — reducing the available workforce and further limiting how much farmland can actually be used. The researchers said this points to the importance of sustainable development models.

The study also found that if cross-border migration is restricted, developed countries could face agricultural labor shortages while some lower-income countries may see an oversupply of farm workers. This indicates that migration policy is closely tied to food security.

"This research analyzed future food challenges by considering not only climate and land, but also changes in human populations," Kim said. "It demonstrates that real social problems — such as low birth rates and the exodus from rural areas — can have a significant impact on future food security and the response to climate change."

The findings were published June 1 in Nature Sustainability.