MILAN (AlertNet) – The world will only be able to feed a rapidly growing population if it improves the use of water, the "most critical finite resource", the head of the United Nations said on Thursday, World Water Day.
"Unless we increase our capacity to use water wisely in agriculture, we will fail to end hunger and we will open the door to a range of other ills, including drought, famine and political instability," U.N. Secretary General Ban Ki-moon said in a statement.
Global food output must double from 2005-2007 levels in developing countries and rise 70 percent in developed nations to feed a world population expected to rise to 9 billion in 2050 from about 7 billion now, according to U.N. estimates.
While an average human drinks 2 to 4 litres of water every day, it takes 2,000 to 5,000 litres of water to produce one person's daily food, the U.N. Food and Agriculture Organization (FAO) said on Thursday.
In many parts of the world, the pace of agricultural production growth has been slowing while water scarcity is increasing and climate change is exacerbating risk and unpredictability for farmers, especially poor ones, Ban said.
Two-thirds of the world's population could be living under water stressed conditions by 2025, the FAO said.
To ensure sustainable food and water security for everyone, the world must boost investments in people, infrastructure, production and education as well as improve water management, FAO's Director General Jose Graziano da Silva said.
"We must meet the agricultural demand in a way that conserves water and other natural resources. From the sustainable intensification of agriculture and using water more intelligently to produce food, to changing the way we eat, reducing losses and waste and promoting healthier diets," he said.
About 1.3 billion tonnes of food are wasted each year, according to FAO estimates.
If food losses and waste are cut by half on the global level that would save 1,350 cubic km of water a year, FAO said.
By comparison, the mean annual rainfall in Spain is 350 cubic km, the storage capacity of Lake Nasser in Egypt and Sudan is nearly 85 cubic km and the water that passes the city of Bonn on the Rhine River in the span of a year adds up to around 60 cubic km, the agency said.
Agriculture is responsible for 70 percent of all freshwater and groundwater withdrawals worldwide, mostly due to farm land irrigation, FAO said.