Updating the self-sufficiency ratio

June 17, 2021

Maximum self-sufficiency is not always desirable – for the more intensive production becomes, the greater the environmental damage. And when biodiversity dwindles and soils erode, the very core of our food supply is threatened. Food security is about far more than just calories – it hinges on an intact natural environment and fertile land. Man is not fed by calories aloneFrom a health perspective too, the classic self-sufficiency ratio makes little sense. So, instead of measuring the self-sufficiency ratio according to current consumption, we could gear it to a balanced diet.

But this rationale no longer holds. Maximum self-sufficiency is not always desirable – for the more intensive production becomes, the greater the environmental damage. And when biodiversity dwindles and soils erode, the very core of our food supply is threatened. Food security is about far more than just calories – it hinges on an intact natural environment and fertile land.

According to analyses made by Vision Agriculture, it’s not the calories produced in normal times that are crucial for a secure supply in crises, but the natural production potential and the ability to adapt the agricultural enterprise quickly when needed.2

Self-sufficiency based on imported energy

A high self-sufficiency ratio does not, therefore, guarantee food security, and partly because this indicator ignores the inputs required for the food produced.

To achieve high levels of supply, farmers use many means of production. They draw on direct energy in the form of fuel, combustible, and electricity, and a larger quantity of indirect or “grey” energy which is stored in the final products – animal feed, and seeds, fertilizers, pesticides, tools, machines and barns. According to estimates, our agriculture requires some two to three times as much external energy as it produces in the form of food.3 Most of this external energy we import, yet the self-sufficiency ratio is based on the means of production being available even in times of crisis.

In my view, in order to evaluate security of supply, an indicator would need to consider the energy balance of domestic production, and negatively account for energy imports. So far, however, methods to meaningfully integrate such dependencies into the food balance are lacking.

This type of approach would also address the climate crisis. Heat, droughts and heavy precipitation already threaten agriculture in many places. As long as imported energy comes from fossil sources and animal feed is grown on cleared virgin forest, our imports will spur climate change and jeopardise domestic yields.

Man is not fed by calories alone

From a health perspective too, the classic self-sufficiency ratio makes little sense. Here, low-energy but nutrient-rich foods such as vegetables and fruits carry little weight, while sugar production scores high due to its high energy content, even though sugar is harmful in the quantities consumed today. We eat unhealthy amounts of meat and dairy products too, but Switzerland itself produces only a small proportion of healthy vegetables, fruits and nuts. So, instead of measuring the self-sufficiency ratio according to current consumption, we could gear it to a balanced diet. In any case, a shift from animal-based to plant-based foods would also boost actual self-sufficiency.

The source of this news is from ETH Zurich
ETH Zurich
Rämistrasse 101, 8092 Zürich, Switzerland

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