What is the Food-Energy-Water Nexus?
Food, Energy, Water……..without these resources, life as we know it cannot exist. The sun provides energy to plants for photosynthesis during which sugars are produced. For sugars to be formed, plants absorb carbon dioxide from the atmosphere and hydrogen from water. With energy from the sun, CO2 from the atmosphere, and hydrogen from water, plants are able to grow and then provide food to animals including humans.
Beyond the very basic level of Food-Energy-Water nexus which was just illustrated in plants photosynthesis above, we humans use all three resources in our daily lives. We eat food (whether vegetarian, vegan, or everything combined), we drink water, and we use energy to power our buildings and lifestyle as a whole.
These resources are scarce and are completely lacking in some areas of the world. Children die of hunger in some part of the world, some humans can’t afford to have potable water in their homes, then energy, mostly in the form of electricity is only luxury that the rich can afford.
Why are these resources scarce, when the ultimate source of energy, which is the Sun is abundantly available and always ready to give life to earth? The problem is in our management of these resources. We have decided to treat the production and consumption of these resources independently rather than inextricably.
In order to maximize existing water, food and energy to meet the growing demand of future population, it is necessary that the systems thinking approach be adopted. The systems thinking approach enables us to study the nexus as a whole rather than in parts and leads us to observe and understand the interactions between the various parts of the entire system.
One simple and interesting way I like to explain this nexus is using a biogas digester. A biogas digester converts organic waste into biogas and liquid fertilizer. Biogas is used as a source of energy for heating, cooking and electricity generation. Liquid fertilizer is a source of nutrients for plants and algae which in turn provides us with food. In waste treatment plants, after the biogas is extracted from the anaerobic digestion phase, the water (liquid fertilizer) is taken to the treatment plant for further purification.
The biogas digester explains perfectly how the nexus works as it shows us how each of these system are interconnected. It however adds an extra component which is waste; The amount of waste put into the digester determines the amount of biogas produced for energy consumption, and the amount of liquid fertilizer produced to supply nutrients to plants and also be retreated into clean water.
With the systems thinking approach, we are able to clearly understand the interactions between the water, energy and food nexus. In order to truly optimize every one of these resources, all independent systems must be looked at as one system. The systems approach would allow us understand the interactions between the sectors, technology and productivity, and also enable the development of the right institutions and policies thereby leading to water, energy and food security for all, equitable and sustainable growth, and also, resilient and a productive environment.
