Evaluating the relationship between natural resource management and agriculture using embodied energy and eco-exergy analyses: A comparative study of nine countries

By shifting from animate labor to ever-increasing fossil fuel and other supplement energy subsidies, energy use in human food supply systems continues to increase. As agriculture is the fundamental manner in which humans interact with the environment, it is especially important to understand the relationships between humans, energy, and food. Many researchers evaluate the material and energy resources involved in the food production chain. Energy return on energy investment (EROI) analyses have been particularly useful in assessing the quantity of energy dissipated versus the energy eventually acquired, thus helping to evaluate the overall efficiency of human food systems (i.e., energy invested versus dietary Calories harvested). A complimentary measure, eco-exergy, has been used to evaluate the quality of energies dissipated and generated in ecosystems. To deepen our insight into the dynamic between humans and their food system, we combine these two measures for a food production analysis. Focusing on meat production, adjusted EROI and eco-exergy ratios are used to evaluate both the quantity and quality of energy accumulated and dissipated in nine country's agricultural processes. Each country's food production indicators are then compared with more established methods of sustainability measurement including ecological footprint and biocapacity. The results reveal a significant, highly correlated relationship between these food production indicators and each country's ecological footprint (resources being consumed) while also showing no correlation to their respective biocapacity (resources actually available), thus quantifying a food production disconnect from the local ecosystem. Using these new metrics, we evaluate which changes in each country's food system could result in more environmentally balanced practices, and also how these changes can be realized.