Will We Soon Run Out of Water?

In 2000, the World population was 6.2 billion; it reached 7 billion in 2012 and should reach 9.5 billion (±0.4) in 2050 and 11 billion (±1.5) in 2100, according to UN projections. The trend after 2100 is still one of global demographic growth, but after 2060, Africa would be the only continent where the population would still increase. The amount of water consumed annually to produce the food necessary to meet the needs varies greatly between countries, from about 600 to 2,500 m 3 /year per capita, depending on their wealth, their food habits (particularly meat consumption), and the percentage of food waste they generate. In 2000, the total food production was on the order of 3,300 million tons (in cereal equivalents). In 2019, about 0.8 billion inhabitants of the planet still suffer from hunger and do not get the nutrition they need to be in good health or, in the case of children, to grow properly (both physically and intellectually). Assuming a World average water consumption for food of 1,300 m 3 /year per capita in 2000, 1,400 m 3 /year in 2050, and 1,500 m 3 /year in 2100, a volume of water of around 8,200 km 3 /year was needed in 2000, 13,000 km 3 /year will be needed in 2050, and 16,500 km 3 /year in 2100. Will that much water be available on earth? Can there be conflicts related to a food deficit? Some preliminary answers and scenarios for food production will be given from a hydrologist viewpoint.