Virtual Water & Vanilla

In order to produce agricultural products, water is necessary. This water is consumed by evapotranspiration, which is why it is possible to identify the water ratio consumed by every food product (FAO 2002, 4).

Virtual water trade describes the movement of water that has been used in the production process of a product (e.g. 1 kg of chocolate consumes over 17.000 litres of water) and is now ‘embedded’ in the product and traded to another place. It is this ‘transfer in space and in time from the production domain to the consumption domain which transforms real into virtual water’ (FAO 2002,4).

The water footprint of a crop (m3/ton) is calculated as the ratio of the volume of water (m3/ha) consumed or polluted during the entire period of crop growth to the corresponding crop yield (ton/ha).

- Mekonnen et al. 2012, 3727

In the assessment of the water footprint of a process, a differentiation is made between blue, green and grey water footprint. The green water footprint includes the rainwater used in the process – the water that is lost to evapotranspiration or consumed by plants (agricultural products etc.). The blue water footprint relates to water used from freshwater resources for irrigation (surface and groundwater). Grey water footprint designates the amount of water required to compensate the pollution caused in the water to attain a  level of water quality that meets specific standards (Water Footprint Network). To calculate the grey water component one divides the amount  of nitrogen that leaches to the water system (kg/ha) by the maximum acceptable concentration of nitrogen (kg/m3) and the crop yield (ton/ha) (Mekonnen et al. 2012, 3727). 

The rational of virtual water trade can be explained by the theory of comparative advantage in international trade, claiming that establishing ‘optimal production sites’ and ‘consumption sites’ will make all actors benefit. Agricultural products will be produced in sites that have available water resources, which will enable the large –scale production that the ‘consumption site’ demands.

Because food trade is likely to increase in the future due to population growth, its implications on water resources and hence water management strategies are obvious. Especially in regions where water is already scarce (e.g. Kenya), I wonder how the increasing transfer of virtual water in food products will be balanced with water needs of local populations.

I think that the transfer of virtual water embedded in traded commodities is becoming an important component of water management on a global and regional level, particularly in water scarce regions. 

According to estimations (Renault & Wallender 2000), 1 260 billion m3 of virtual water were used globally for agricultural food products in 2000.

One of the main arguments supporting virtual water trade is that importing countries are saving water. These savings can be calculated through the following formula:

Water savings (m3) = Import (kg) x Virtual Water Value (local site)

For example, Egypt saved 5.8 billions m3 of water in 2000 by importing rather than internally producing the 5.3 millions tons of maize needed for domestic consumption (FAO 2002, 15).

Even though this water saving mechanism is highly beneficial for the consuming country, the pressing question arises - at what cost ? Surely, in the ideal scenario of the comparative advantage theory, both parties benefit because one country uses a resource that is abundant in the other. However when we think of Sub Saharan Africa and its trade relations with the global North, I would argue that reality is far from this ideal scenario. The lack of institutions, corrupt governments and neglected land and water rights are potential reasons why a transparent assessment of the actual cost of virtual water trade might become a highly difficult endeavour in many African countries.

On the website of the ’water footprint network’, the organisation has provided a rich database by gathering statistics of national and international water flows. A particularly interesting document is their spread sheet on crops, in which the blue, green and grey water footprints of a large range of crops are calculated for all countries at national and subnational level. Here the link: Water Footprint Statistics

When I was scrolling through this massive spreadsheet, there was one particular crop that stood out to me with one of the highest amounts of water used – Vanilla Beans. In order to produce 1 ton of vanilla beans  in North Eastern Kenya 21.000 m3 of rainwater are incorporated (evaporated) in the growing process and almost 70.000 m3 of irrigated water are required (Mekonnen, M.M. and Hoekstra, A.Y. 2011). 

The case of Vanilla Beans becomes particularly striking when we think of a country where this commodity is exported at a much larger scale: Madagascar. While Kenya has only exported some 100 kg in 2014, Madagascar traded around 2.300 tons of Vanilla Beans to foreign countries…

These are huge amounts of freshwater used in the production process of this agricultural product and I am asking myself again – at what cost?

In our daily lives, vanilla beans play a quite negligible role. We might appreciate their taste when getting a Vanilla Latte at Starbucks or lighting a aromatic candle, but have we ever thought about the amounts of water it will take to produce this tiny, trivial product in North Eastern Kenya or Madgascar – just so that we can spice up our morning coffee or add a comforting scent to our living room?

In the next blog post I hope to elaborate more on the virtual water footprint of a horticultural crop product in Kenya: flowers. 

References:

Antonelli, M. and Tamea, S. (2015). Food-water security and virtual water trade in the Middle East and North Africa. International Journal of Water Resources Development, 31(3), pp.326-342

Mekonnen, M.M. and Hoekstra, A.Y. (2011) The green, blue and grey water footprint of crops and derived crop products, Hydrology and Earth System Sciences, 15(5): 1577-1600.

Mekonnen, M.M. and Hoekstra, A.Y. (2011) National water footprint accounts: the green, blue and grey water footprint of production and consumption, Value of Water Research Report Series No. 50, UNESCO-IHE, Delft, the Netherlands.

Renault, D. (2002). Value of Virtual Water in Food: Principles and Virtues. [online] Rome: FAO. Available at: http://www.fao.org/nr/water/docs/virtualWater.pdf [Accessed 3 Jan. 2017].

Renault D., Wallender. W.W. 2000. “Nutritional Water Productivity and Diets : From « Crop per drop » towards « Nutrition per drop » “. Agricultural Water Management, 45:275-296.

Waterfootprint.org. (2016). Home. [online] Available at: http://waterfootprint.org/en/ [Accessed 9 Jan. 2017].