The Water-Food-Energy Nexus
Let’s see the answer with the help of the upcoming and relevant Water-Food-Energy Nexus approach. With a growing global population seeking increasing prosperity every year, water, food and energy consumption is likely to increase by 30-50% over the next 25 years. Traditional resource management strategies usually focus on either water, food or energy. This article shows that the three sectors are highly interlinked and they should be approached in an integral way. Now let’s explore some of these links.
All food production requires water and 70% of global fresh water (withdrawals from wetlands, lakes and aquifers) is used for irrigation. Additionally, the production of crops for feeding livestock, the slaughtering and processing of meat, milk and other dairy products also require large quantities of water. For instance, it takes about 1500 liters of water to produce 1kg of wheat, and about ten times more water to produce 1 kg of beef. As for water quality, in agriculture, overuse of chemical fertilizers and pesticides contaminate water bodies. Intensive livestock production also impacts on the quality of water resources.
The mechanization of agricultural production increases productivity and improves the continuity and quality of outputs, however this process requires increasing energy inputs. The increased benefits that have resulted from mechanization have come at a high energy price, as the full food and supply chain claims approximately 30% of total global energy demand. Energy fuels are also needed for land preparation, fertilizer production, irrigation and sowing, harvesting and transportation of crops. Moreover, this energy largely derives from fossil fuels. But since fossil fuels eventually run out, it is important to increase our use of renewable energy strategies or start consuming less.
Agriculture itself could also be a source of energy in the form of bioenergy (e.g. biofuel, biomass, biogas). While this may reduce our greenhouse gas emission, some forms of bioenergy are controversial. Large pieces of land, sometimes within protected areas, are used to plant crops, such as fast-growing trees and grasses, so-called biomass feedstocks, which then cannot be used for other types of agriculture.Consequently, this raises food prices.
Many forms of energy production from fossil fuels are highly polluting and water consuming. In contrast, energy is needed for extracting, transporting, distributing and treating water. Irrigation is more energy intensive than rain-fed agriculture, and drip irrigation is more intensive since the water must be under pressure.
Electrical energy is used to treat and transport water and wastewater. Moreover, the energy related to water use – mostly heating the water in households and industries – requires about ten times more energy than the energy needed to deliver clean and cold water or treating the wastewater.
Around one third of the food produced globally is wasted, although more than one billion people around the world suffer from hunger. The European Commission calculates that in the EU 90 million tonnes of food or 180 kg per capita are wasted every year. Much of this food is still suitable for human consumption.
Food waste also represents a loss of other resources such as land, water, energy and work.
There are still many discussion on the topic of food waste. However, the common idea is that we need new approaches, such as recognition of the complex connection between the three sectors and rethink how not to waste our food in order to manage resources in a more sustainable way.
by Judit Suveges
: Lundqvist, J., C. de Fraiture and D. Molden. (2008). Saving Water: From Field to Fork – Curbing Losses and Wastage in the Food Chain. SIWI Policy Brief. SIWI, 2-8. Institute, Stockholm4-13.
: Halweil, B. and Nierenberg D. (2008). Meat and seafood: The global diet’s most costly ingredients, State of the world: Innovations for a sustainable economy, 61-74.
WFE Nexus: http://www.dhigroup.com/-/media/images/news/2012/08/nexus%20news
Water-Food footprint: http://www.eniscuola.net/wp-content/uploads/2014/02/water_footprint_food.jpg
Energy-food diagram: http://media.treehugger.com/assets/images/2011/10/food-energy.png
Food waste infographic: http://blog.kulikulifoods.com/wp-content/uploads/2015/09/Food-Waste-Infographic.png
Food waste: http://thumbnails-visually.netdna-ssl.com/rotten–global-annual-food-waste_5182d807d7c29.jpg