The new study used production and trade data for agricultural food commodities collected by the United Nations' Food and Agriculture Organization (FAO) to examine global food security and the global patterns of food trade – something that the authors suggest has been ‘minimally studied’.
Using the FAO commodities and trade data, the study reconstructs the global food trade network in terms of food calories traded among countries – finding that as the world population continues to grow, the global food supply may not meet escalating demand, particularly for agriculturally poor countries in arid to semi-arid regions, such as Africa's Sahel, that already depend on imports for much of their food supply.
"We found that, in the period between 1986 and 2009, the amount of food that is traded has more than doubled and the global food network has become 50% more interconnected," said Professor Paolo D'Odorico, from the University of Virginia – who led the study. "International food trade now accounts for 23% of global food production, much of that production moving from agriculturally rich countries to poorer ones."
Writing in the journal Earth's Future, D'Odorico and his colleagues found, however, that trade has not eradicated food insufficiency in sub-Saharan Africa and central Asia.
"Overall, in the last two decades there has been an increase in the number of trade-dependent countries that reach sufficiency through their reliance on trade," D'Odorico said. "Those countries may become more vulnerable in periods of food shortage, such as happened during a 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."
These ‘food crises’ were caused by extreme climate events that brought drought conditions to several food-exporting nations including Russia, Ukraine and the United States, they explained.
The new study analysed the role of food trade in different regions of the world, with maps showing areas of food self-sufficiency and trade dependency.
D'Odorico and his co-authors 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 in the Sahel region, a vast, populous, semi-arid region stretching across the central portion of the African continent that otherwise would not be able to produce enough food for its populations.
The team reported that just 13 agricultural products – wheat, soybean, palm oil, maize, sugars and others – make up 80% of the world's diet and food trade.
They also noted that China is greatly increasing its consumption of meat, which already is changing land-use patterns in that country, because meat production requires significantly more land area then crops.
"Fats and proteins tend to increase with the economic development of emerging countries," said D'Odorico. "An increase in consumption of animal products is further enhancing the human pressure on croplands and rangelands."
Indeed, the US-based Professor noted that some countries, such as the U.S. and Brazil, are ‘blessed’ with climates and soils that are conducive to high agricultural yields, and also the technologies – such industrial fertilisers, sophisticated large-scale irrigation, new resilient cultivars – and financial resources to sustain high yields, and therefore are major exporters of food to agriculturally poor nations.
However, he noted that as populations grow and climate change brings currently unforeseeable changes to growing conditions, it is very possible that these exports to other nations could be reduced.
"The food security for rapidly growing populations in the world increasingly is dependent on trade,” he warned. “In the future, that trade may not always be reliable due to uncertainties in crop yields and food price volatility resulting from climate change.”
"The world is more interconnected than ever, and the world food supply increasingly depends on this connection," said the expert. “Trade can redistribute food, but it cannot necessarily increase its availability.”
Source: Earth's Future
Published online ahead of print, doi: 10.1002/2014EF000250
“Feeding humanity through global food trade”
Authors: Paolo D'Odorico, Joel A. Carr, et al