26 March 2019

PLOS ONE Publication

Food trade increases resilience against climate fluctuations

The global network of food trade increases resilience against interannual-decadal climate variability, a modelling study by Utrecht University researchers published in the open access journal PLOS ONE finds.

Food Trade
Trade is central to food security in our globalised and urbanised world.

Trade is central to food security in our globalised and urbanised world. Under anthropogenic climate change, variability in food production is likely to increase. Therefore, it is crucial to understand how the interplay between trade and climate variability impact food security. Researchers at the Copernicus Institute of Sustainable Development and the Physical Geography department of Utrecht University have developed a model to explore how resilient a food trade network is to climate variability.

Competition for food resources

The model comprises a network of nodes that competitively interact for the inflow of food resources. The amount of resources in the network vary over space and time to reflect the impact that climate oscillations such as the El Niño Southern Oscillation (ENSO) have on food production. Under the influence of climate variability one part of the trade network may have a surplus of resources whilst the other has a shortage (see figure). The researchers also explored how sudden shocks arising from extreme climate events, such as droughts, may spread in the network.

Food Trade Network
Under the influence of climate variability one part of the trade network may have a surplus of resources whilst the other has a shortage.

Increased capacity

Their results show that trade increases the carrying capacity (i.e. the maximum population that can be sustained) of the network when climatic fluctuations lead to opposing effects on resource availability. For example, during an El Niño, maize and soybean growing conditions in the US and southeast South America are favourable, whilst conditions are poor in northern China. Via trade the deficits in China can be compensated by surplus in the US and South America.

Denser network is more efficient

They also find that a denser network results in a more efficient and even redistribution of resources among nodes. Central nodes grow larger populations compared with peripheral nodes as they have a shorter average path to resources in the network and thus a competitive advantage. They are also more resilient to sudden shocks for the same reason. However, this high connectivity means that sudden shocks originating in central nodes will have a greater negative impact on carrying capacity within the network. This was seen in 2010 when Russia and the Ukraine experienced severe crop losses owing to drought, leading to a drop in wheat supplies to global markets.

Trade is a double-edged sword

“This model highlights that food trade is vital for maximizing carry capacity and building resilience against interannual-decadal climate variability” says lead author Alexander Dolfing. “However, for more sudden shocks arising from extreme events such as droughts or floods, trade can be a double-edged sword depending on where the shock occurs in the network.”

Senior author Brian Dermody adds: “More than half the world’s population now live and cities and depend on trade. Therefore, it is imperative to develop our understanding of the complex interplay between urbanisation, globalisation and climate change in the context of food security and sustainability.”