New research assessing the food supply available to more than 140 countries with populations greater than one million people has found that food security issues are becoming increasingly susceptible to small changes in population growth and demographics.
Writing in Proceedings of the National Academy of Sciences (PNAS), the team warned that escalating demand for food from a growing and increasingly affluent global population is placing ‘unprecedented pressure’ on the limited land and water resources of the planet, and that such pressure is underpinning concerns over global food security and its sensitivity to shocks arising from environmental fluctuations, trade policies, and market volatility.
"In the past few decades there has been an intensification of international food trade and an increase in the number of countries that depend on food imports," commented Professor Paolo D'Odorico, from the University of Virginia – who led the study. "On average, about one-fourth of the food we eat is available to us through international trade. This globalization of food may contribute to the spread of the effects of local shocks in food production throughout the world."
The team used country-specific demographic records along with food production and trade data for the past 25 years to evaluate the stability and reactivity of the relationship between population dynamics and food availability.
Using computer modelling, D'Odorico and colleagues reconstructed the global network of food trade between 1986 and 2011 in conjunction with a population growth model, factoring in the constraints of food availability through domestic production and trade, and examined the response of the system to perturbations.
They found that the coupled dynamics of population and access to food are becoming less resilient and increasingly prone to instability.
Countries that strongly depend on trade for their food supply appear to be more susceptible to instability and episodic food crises than exporting countries, they said – adding that the findings are consistent with the food insecurity that has affected trade-dependent countries during recent food crises.
"In order to have food security, food availability and accessibility need to be sustainable and resilient to perturbations associated with shocks in production and price spikes," said D'Odorico.
"We're finding that as the globalization of food increases, the coupled population/food system becomes more fragile and susceptible to conditions of crisis."
Published online ahead of print, doi: 10.1073/pnas.1507366112
"Resilience and reactivity of global food security"
Authors: Samir Suweis, et al