Water Scarcity - The Ripple Effect: The Fate of Freshwater in the Twenty-First Century - page 106

According to the National Center for Health Statistics, more babies were born in the
United States in 2007 than in any other year in American history. The 4.3 million births
that year even eclipsed the number of births in 1957, at the height of the baby boom. It
is estimated that the US population will increase by over 100 million people in the next
thirty to forty years. The water footprint of 100 million more Americans will be enorm-
ous. But it will pale in comparison to the water stress that will be felt in the developing
world.
Most of the additional 2 billion people who are expected to join the global popula-
tion by 2025 will come from developing nations that are already burdened by a lack of
clean drinking water and effective sanitation. To feed an additional 2 billion people, the
UN estimates, will require as much as 60 percent more water than is currently used by
agriculture (assuming no changes in efficiency). But almost every available water source
has already been tapped, and many have been overused.
Absolute numbers of people don't influence water demand as much as changing diet
and lifestyle do. Irrigated agriculture accounts for about 70 percent of the world's fresh-
water use, but different diets consume different amounts of water. The largely vegetari-
an diets of Africa and Asia use about 2,000 liters of water a day, while the carnivorous
Euro-American diner requires 5,000 liters a day (and another 100 to 250 liters of water
per day for drinking and washing).
As developing nations aspire to first-world status, global diets are becoming more
meat-oriented, and thus more water-intensive, due to the water required to raise anim-
als. In 1985, a typical Chinese person ate about 20 kg of meat per year; in 2009, he ate
50 kg. This shift represents 390 cubic kilometers of water (1 cubic kilometer of water is
1 trillion liters) per year, which is nearly the total use of water in Europe, according to
the Economist.
If global trade patterns better reflected the amount of water required to manufacture
food and other products, many economists believe that water would be used more effi-
ciently and that people would make better-informed decisions about what they buy.
The subtler point is that wealthy societies use more resources and create more pol-
lution than poor ones do. The onus to change how water is used, therefore, rests with
those who use it most. But people don't like change, and convincing them to forfeit old
entitlements will be difficult. As the effects of climate change are felt, however, change
will be thrust upon us.
Climatologists predict that drought will increase in many of the world's most densely
populated regions this century, and that global warming is the second major trend that
will significantly impact water supplies.