Too little water in too many cities. Learned Discourses

“URBANIZATION AND WATER SCARCITY
Cities are home to many. There are currently more than 400
cities with more than 1 million inhabitants and 23 megacities
(metropolitan areas with a population of more than 10
million), mainly in Asia (United Nations 2012). According
to the United Nations (UN), 50% of people live in cities and, by
2050, 67% of all humans will be living in cities. In developed
countries this percentage is even higher (more than 86%).
The speed at which global urbanization is taking place is
unparalleled. In 1970, for example, there were just 2
megacities (Tokyo and New York), in 1990 there were 10,
in 2011, 23, and by 2025 there will be 37 megacities. Just how
impressive this urbanization is becomes apparent when you
look at the growth forecasts. The UN estimates that, between
2011 and 2050, the world population will grow from 7 to 9.3
billion and that the population in cities will increase from 3.6 to
6.3 billion, whereas the number of people living in rural areas
will decline.
This means that future growth in the world’s population will
be absorbed by cities. Together with the migration from rural
areas to cities, during this period more than 200,000 people—a
day—will need to find a new place to live in an urban
environment. This will be accompanied by strong growth in
urban water demands, especially in fast growing urban regions
in East and West Africa, South America, and Asia (Dobbs et al.
2012).”

(Citaat: van Leeuwen, C.J. – Too little water in too many cities. Learned Discourses; Timely Scientific Opinions – Integrated Environmental Assessment and Management 11(2015)1, p.171-173)