Sustainability assessment of farming in perspective of diminishing global emerge flows – A case study

Central to the emergy world-view is the realization of a pulsing world with the modern civilization being characterised as a mega pulse fuelled by fossil fuels. However, this basic assumption is often neglected when emergy flows are used to assess sustainability. For instance, when emergy calculations are exclusively based on present data and conditions (e.g. transformity for labour and services), it is ignored that future national emergy flows will be reduced as non-renewable stocks deplete and become harder to extract.
Sustainability assessments should in our opinion address the capacity of a system to sustain its integrity in a changing socio-ecological environment. We believe that an important objective is to identify and assess systems that can show a prosperous way down from the mega pulse.
The case in our work is a dedicated organic stockless UK farming system with distribution of products to customers. The farm has systematically and successfully worked on reducing external inputs to an extent where only fossil fuel and labour are significant. The farm is, therefore, considered to be a best case for a resilient food system. We present and compare two emergy analyses of the system; one under current conditions and another under future conditions. In order to analyse the system in the latter conditions, scenarios for national emergy flows are explicitly formulated. The comparison among others show that when labour becomes less emergy intensive, it may to some extend be seen as a suitable substitute for fossil fuel for the farm.