From Food to Energy: a Bridge from Milano EXPO 2015 to Astana Expo 2017

Food is our energy and especially today a lot of energy goes into the food supply chain; from agricultural land management to food processing, storage and transportation. This work is born as a bridge between the EXPO 2015 held in Milan on the subject "Feeding the Planet, Energy for Life" and the EXPO 2017 that will be in Astana, on the subject "Future energy". About 10000 years ago, from 1 calorie spent as muscular work to obtain food products, Neolithic man gained 15 to 40 calories in nutritional value, depending on the product and on climatic conditions; to feed one person a few hectares of fertile soil had to be exploited on average [1]. Today the world average is about 0.2 hectares per person. Only the supply of greater energy flows, both directly as fuel or electricity and indirectly in the form of chemicals or agricultural machinery, has enabled a simultaneous world population growth and an increase in average food availability per capita. This is bringing the attention to another important resource of our planet that is at the base of the food chain: water. Over two-thirds of the planet is covered by water but only about 2.5% is fresh water: 70% of annual freshwater withdrawals is used for agriculture, 20% for domestic or industrial use, 10% for energy. In fact, 70% of the fresh water we use, is used to feed the planet. Here the energy-water-food nexus has its roots.