Vanishing Water: Rescuing the Neglected Food Resource

Abstract

The annual global amount of water consumed to produce food ranges from 600,000 to 2.5 million liters per capita depending on food habits and food waste generation. Humans need approximately 2–3 L of water daily to maintain health, but only 0.01% of the world’s water is drinkable. Food supplies cannot be generated without land, water, and energy use. The current use of water for production of food is most concerning and requires immediate and increased awareness. Minimal attention has been devoted to the increasing water scarcity and loss of drinking water. Food waste also contains water and therefore also adds to water scarcity that is affecting almost 4 billion people. We summarize the human need of water, its significance for life and for the production, processing, and consumption of foods. This review includes an examination of the history of water; the unique properties of water for sustaining life; water for food production including agriculture, horticulture, and mariculture; the properties of water exploited in food processing; water scarcity due to water demands exceeding availability or access; and its consequences for our world. Means to reduce water scarcity, including using water treatment and promoting change of human habits, are discussed. The future of water and the recommendations for action are proposed for decreasing water scarcity and reducing water use during food production, food processing, food preparation, and consumption.