Virtual Water: A solution to food insecurity in sub-Saharan Africa?

How does the concept of virtual water trading fit into the context of sub-Saharan Africa?

Whilst encouraging dependence on food importation (virtual water trading) is incongruous with the politicised goal of food-production self-sufficiency in many sub-Saharan Africa countries, it is in many ways a sensible solution on ecological, hydrological and in many cases socio-economic grounds. Water is increasingly becoming the limiting factor in agricultural production across sub-Saharan Africa, both as a result of highly variable climatic patterns and increasing competition with health, energy and ecosystem services. As discussed in my second blog post, staple and export crops like sugar cane and rice are increasingly inefficiently produced across sub-Saharan Africa, with more water resources used and less yield achieved compared to global benchmarks (Xie et al. 2018). Climate change is predicted to make sustainable water use harder to achieve especially when coupled with the growing population of sub-Saharan Africa, it is also predicted to drastically alter the types of crops that can grown in different areas (Fig. 1.). Some countries in the region have looked to begin managing imports and exports based on embedded virtual water content, following the footsteps of the water-stressed large net virtual water importers in North Africa and the Middle East (Lillywhite 2010).

Fig.1. An infographic made by Down To Earth highlights the importance
of agricultural adaptation to climate change.

Ethiopia is a landlocked country located in the horn of Africa. It has consistently suffered with chronic food insecurity largely as a result of high vulnerability to water scarcity and climate variability. Ethiopia’s food production is largely reliant on rain-fed agriculture with only 3% of its land under irrigation, suggesting that the nation will become increasingly food insecure as precipitation vulnerability intensifies with climate change. Ethiopia’s water shortages have been more frequent and severe since the middle of the 20^th century, resulting in agricultural production shortages almost biennially. Whilst one solution to this food insecurity could be to reduce the limiting effect of the climate through increased irrigation (as covered in earlier blog posts), Karapinar (2011) highlights the potential  virtual water importation could have on improving food security.

Research by Dalin and Conway (2016) has highlighted the success of virtual water trading in Southern Africa, a region with high spatial and temporal rainfall variability reliant on rain-fed agriculture. They found that heterogeneity in water productivity and resource availability across the 13 nations of the Southern Africa Development Community, results in resource efficiency gains through intra-regional virtual water trade as compared to self-sufficiency models. A move towards a more regional trade-oriented food supply may however be unsustainable, with some regional virtual-water exporters such as South Africa overusing its water resources (Dalin and Conway 2016). The region as a whole is a large importer of virtual water with extra-regional imports increasing by a factor of 10 from 1986 to 2011, largely to compensate for low productivity and yields in the region (Dalin and Conway 2016).

To what extent is trading in virtual water a solution to food insecurity in sub-Saharan Africa?

Virtual water trading in both regional and global contexts has consistently been shown to improve agricultural water efficiency and food security, especially increasing resilience in times of severe localised climate shocks such as drought (Dalinand Conway 2016). It is unclear however, at least in the case of Southern Africa, to what extent the effects of more mild and localised droughts and inter-annual climate variability are reduced through virtual water trade (Dalinand Conway 2016). Furthermore, whilst the regional trade model does generally drive efficient resource allocation (with more water productive areas exporting virtual water to less water productive areas), in regional contexts where the major virtual water exporters are also facing freshwater scarcity (i.e. Southern Africa) the whole trade system’s sustainability becomes at risk. This reality needs to be considered further before decisions are made on a regional level regarding trade, water and agriculture (Dalin and Conway 2016).

Inequality is rife across the free market, only serving those with the purchasing power to express their worth. A virtual water trade model developed by Susweis et al. (2011) highlights this ‘rich club phenomenon’ problem, finding that 80% of virtual water flows over only 4% of trade links. The link between two of the ‘rich-club’ members, Japan and the USA, facilitated approximately 5% of global virtual water flow. The model is also able to forecast future  scenarios under climate change such as increased drought and intense precipitation events, all of which suggest an intensification and increase in power of the rich club monopoly (Susweis et al. 2011). The power of private wealth in politics can also prove detrimental with oligopolies occurring in sectors such as the grain trade, with 4 companies owning 90% of global market share (The Guardian 2011).

Adopting virtual water trade-oriented policy does show promise for sub-Saharan Africa, however system sustainability and effectiveness under future climate scenarios does question its merit as a full-time agricultural policy to achieve food security. The inequality within the free market system could also pose a barrier for those countries that are relatively cash-poor, preventing them from accessing economical trade opportunities. Other facets of the virtual water argument also need to be further explored such as the possibility for disproportionate demographic growth as a result of over-reliance on virtual water-imports (D’Odorico et al. 2010).

Alternative solution:

D’Ordorico et al. (2010) have proposed a modified version of virtual water trade based upon the concept of water solidarity, this model appears to be better suited to the sub-Saharan context by achieving food security in a sustainable manner. The model focuses on two main premises:

•    Long distance food trading mainly occurs as a security measure in times of food shortage or agricultural failure.
•    Imported virtual water must not exceed the carrying capacity the region would have in periods of no drought to prevent over-reliance.

The water solidarity model advocates for the trade of virtual water to remain local except during periods of regional crop failure in which international transport of virtual water is activated. Whilst development is required to ensure effective and swift solidarity mechanisms in the occurrence of crises, the model still has the ability to reduce rates of drought induced mortality through improving food security. Dalin and Conway (2016) also advocate this approach for the Southern Africa region where current virtual water trading is unsustainable (because exporters resources are becoming increasingly stressed). Local improvements in water productivity in tandem with agricultural expansion in the humid importing countries could lead to more optimal resource use. This strategy treats virtual water as more of a food insecurity buffer, encouraging nations and regions to still develop their own agricultural sectors to meet the majority of their food needs.