In engineering an important component of resilience and reliance is redundancy, defined as idle components that will be taken into the process if the principal component fails. For example, in hospitals, power generators are normally installed and kept in stand-by in addition to the normal power source. The idea of our recently published article (Fader et al., 2016) was to borrow the concept of redundancy from engineering and apply it to food security. For doing so, and in terms of food production, we consider that the biophysical redundancy of each country is composed by three elements: a) the spare, fertile land, b) the unused freshwater resources, and c) the possibility of increasing agricultural productivity, that means producing more using the same water and land resources.
What this study does is to combine these three components in a biophysical redundancy index for each country and investigate how this index has changed in the last two decades.
Since it is not trivial to know how much land and water is idle in every country, how much these resources can produce, and especially how much of these resources could be used sustainably, we defined a set of 16 scenarios combining different water availability and productivity, water reserves for environmental flow requirements, land availability, protected areas, areas worthy of protection, and yield gap closure on cultivated and unused areas.
The results indicate that in 2012 there were 75 countries that could not feed at least 50% of their population during a year with redundant resources. Those include all countries from the Eastern and Southern Mediterranean, and Spain. France and Italy are close to the edge of limited biophysical redundancy, with values between 50 and 60% of their population.
Fig. 1: Index of biophysical redundancy for 2012. Source: subset of Fig. 1e in Fader et al., 2016.
Biophysical redundancy has decreased in the last two decades in most countries, excepting some countries of Eastern Europe. From the countries of the Mediterranean, Algeria, Turkey and Libya have made a transition from high to limited redundancy; and Spain and Tunisia from limited to very low redundancy. The world as a whole has also a decreasing trend in redundancy. In the lowest redundancy scenario, humanity just completed the transition from limited to very low biophysical redundancy.
The study also looks at 28 countries classified as Low-Income-Economies that are mainly situated in Sub-Saharan Africa. The special character of these countries is that they are particularly vulnerable to domestic or external food supply changes due to their limited capacity to increase imports in the event of a food shortage. From these 28 countries, 9 have nowadays limited or very low biophysical redundancy. And 6 other ones are expected to make the transition towards low redundancy in the next 50 years.
The study highlights the necessity of further developing indexes by integrating the influence of international trade on food security.
Reference: Fader, M.; Rulli, MC.; Carr, J.; Dell'Angelo, J.; D'Odorico, P.; Gephart, J.; Kummu, M.; Magliocca, N. et al. Past and present biophysical redundancy of countries as a buffer to changes in food supply. Environmental Research Letters, 2016.