As the demand for food rises with a growth in world population, trade may not guarantee food security to countries heavily dependent on imports for their food supply, says a study.

“The food security for rapidly growing populations in the world is increasingly dependent on trade,” said lead author of the study Paolo D’Odorico, professor from the University of Virginia in the US.

“In the future, trade may not always be reliable due to uncertainties in crop yields and food price volatility resulting from climate change,” D’Odorico noted.

“Trade can redistribute food, but it cannot necessarily increase its availability,” D’Odorico explained.

As the world population continues to grow by about 1 billion people every 12 to 14 years since the 1960s, the global food supply may not meet the escalating demand – particularly for agriculturally poor countries and arid to semi-arid regions, the findings showed.

The researchers demonstrated that most of Africa and the Middle East are not self-sufficient, but trade has improved access to food in the Middle East and the Sahel region.

The investigators found, however, that trade has not eradicated food insufficiency in sub-Saharan Africa and central Asia.

“Those countries may become more vulnerable in periods of food shortage, such as happened during the food crises in 2008 and 2011, when the governments of some producing countries banned or limited food experts, causing anxiety in many trade dependent countries,” D’Odorico noted.

For the study, the researchers examined global food security and the patterns of food trade.

Using data for agricultural food commodities collected by the United Nations’ Food and Agriculture Organization (FAO), the study reconstructed the global food trade network in terms of food calories traded among countries.

As populations grow and climate change brings unforeseeable changes to growing conditions, it is possible that exports to other nations could be reduced, the team explained.

The study appeared in the journal Earth’s Future.