How does a potentially devastating disturbance, such as drought or excess rainfall, effect the ripples of trade flow in sub-Saharan Africa? What is the spatial relationship between biophysical characteristics and net exports in a particular country or region? What do historical patterns and spatial variability in the environment, agricultural production, and natural shocks tell us about food distribution and possible mitigation through responsive trade flows? HarvestChoice explores these questions in a recently published chapter included in the flagship publication, ReSAKSS Annual Trends and Outlook Report (ATOR) 2013.

Simply put, agricultural resilience can be described as the capacity to resist, absorb, recover, or possibly adapt to disturbances in the environment, whether it be at the crop, household, regional, or country level. Disturbances include extreme weather shocks such as excessive rain, prolonged drought, soil depletion, and deforestation. Resilience also impacts trade flows at the borders. For example, a shock that occurs in one country has a ripple effect on all its commercial partners. Shocks skew the balance between imports and exports by creating abrupt changes in consumer incomes and demands on the import side, and agricultural production on the export side. A recent study led by HarvestChoice sheds light on some of the patterns and possible mechanisms that control the flow of agricultural trade in the ECOWAS (The Economic Community Of West African State) and COMESA (Common Market for Eastern and Southern Africa) regions of sub-Saharan Africa, by exploring the spatial relationship between biophysical characteristics and net exports (imports-exports), and also explores the possibilities of mitigating agricultural risk and shock through responsive trade flows.

Modeled simulation scenarios considered three natural shocks:
• Total annual rainfall decrease by 50 percent (drought)
• Average NDVI decrease by 25 percent (vegetation loss)
• Temperature increase by 1°C (warming)

Results from simulation models show that climate matters. Biophysical variables, such as rainfall and temperature, not only strongly influence total agricultural output, but also net exports (see figures above). This suggests that climate-related variables are key for profitable farming as well as flourishing trade flows.

By examining the geographical and historical distribution of trends in production and natural shocks across Africa, windows of opportunities become apparent for agriculture adaptation and mitigation strategies to increase smallholder farmers’ resilience to natural shocks. For example, by comparing areas of drought to areas of rain surplus at the African continent level over a 30-year period, about 40 percent of the time the losses in maize production due to drought might have been mitigated by trade. In other words, in 4 out of every 10 years there were more areas of rain surplus than drought. For the remaining 60 percent of the time, there were more areas of drought than rain surplus, and trade was constrained by overt losses in maize production.

In another example, the spatial visualization of cereal-production and cereal-consumption in a given year confirms the inequitable availability of cereals among African regions and countries within the same region (see figure above). Such cereal balances indicate regional hotspots of distribution.

In summary, findings of the study indicate that biophysical risks associated with climate change, if unmitigated, would, in the long run, erode the capacity of countries to use trans-border trade to stabilize domestic food markets—highlighting the intricate relationships between ecosystem resilience and food system resilience, and the role of trade in linking the two. While trade can enhance food system resilience to current ecosystem shocks, such shocks, if persistent and severe enough, would gradually undermine the ability of food systems to absorb them. In other words, trade can at best offer temporary relief from the effects of climate shocks. Strategies to enhance food system resilience should therefore consider trade as an important part of a broader agenda to fight climate shocks and reduce their impacts on production systems.

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HarvestChoice, 2014. "Balancing the Tide of Good Fortune and Mitigating Shocks: Agricultural Trade Flow and Resilience in sub-Saharan African ." International Food Policy Research Institute, Washington, DC., and University of Minnesota, St. Paul, MN. Available online at

Nov 17, 2014