Some 1.2 billion people—almost one fifth of the world—live in areas of physical water scarcity, while another 1.6 billion face what can be called economic water shortage. The situation is only expected to worsen as population growth, climate change, investment and management shortfalls, and inefficient use of existing resources restrict the amount of water available to people. It is estimated that by 2025 fully 1.8 billion people will live in countries or regions with absolute water scarcity, with almost half of the world living in conditions of water stress.
Agriculture is the most water-intensive sector
, currently accounting for more than 70 percent of consumptive use. Agricultural water withdrawal accounts for 44 percent of total water withdrawal among members of the Organisation for Economic Co-operation and Development (OECD), but this rises to more than 60 percent within the eight OECD countries that rely heavily on irrigated agriculture. In the four transitional economies of Brazil, Russia, India, and China, agriculture accounts for 74 percent of water withdrawals, but this ranges from 20 percent in the Russia to 87 percent in India.
The full story on water scarcity below the fold.
While the growing world population is increasing the pressure on land and water resources, economic growth and individual wealth are shifting people from predominantly starch-based diets to meat and dairy, which require more water. Producing 1 kilogram of rice, for example, requires about 3,500 liters of water, while 1 kilogram of beef needs some 15,000 liters. This dietary shift has had the greatest impact on water consumption over the past 30 years and is likely to continue well into the middle of this century, according to FAO.
The U.S. has the second greatest per capita meat consumption, after Luxembourg, and since it is also one of the largest exporters of animal feed globally its water use for animal agriculture is 50 percent of its total water use!
Leading water scientists from the The Stockholm International Water Institute are issuing a warning
that food shortages in the future will dictate a global transition to vegetarian diets by 2050.
"Adopting a vegetarian diet is one option to increase the amount of water available to grow more food in an increasingly climate-erratic world," the scientists said. Animal protein-rich food consumes five to 10 times more water than a vegetarian diet. One third of the world's arable land is used to grow crops to feed animals.