282
S
ince the 1950s, the term
“urban sprawl” has been
widely used to describe the
growth of low-density suburbs
beyond high-density city cores.
The term was first used by The
Times newspaper in the UK in 1955
to describe the spread of London’s
suburbs. At this time, the British
planning authorities were
introducing “green belts” around
cities, where new building was
almost entirely banned. Green
belts were designed to stop cities
from spreading and merging with
other towns.Modern definitions of urban sprawl
vary, but it generally has negative
overtones. At its most extreme, it
has created megacities—defined by
the United Nations as cities of more
than 10 million people. Examples
of such megacities include Tokyo-
Yokohama (38 million), Jakarta
(30 million), and Delhi (25 million).Ecological upset
Some researchers claim urban
sprawl is the most serious threat
to biodiversity from any human
activity. The new suburbs house
relatively few people, yet require
extensive and disproportionate
levels of infrastructure, such as
power and water supplies and
transportation networks. As cities
swell, valuable farmland is covered
in concrete and natural habitats are
disrupted or lost entirely. Sprawl can
also disturb local fauna and flora
through the introduction of pets
and invasive plants that threaten
indigenous species. Limited public
transportation in low density
areas also means that suburban
populations tend to be multiple car
owners, which adds to the levels
of air pollution in cities—as do the
wood- and coal-burning stoves of
the poor in outlying shanty towns.IN CONTEXT
KEY FIGURE
Robert Bruegmann (1948–)BEFORE
1928 British architect Clough
Williams-Ellis compares
London’s growth to an octopus
devouring the countryside.1950s With postwar prosperity
and increased car ownership in
the US, the middle classes leave
cramped city centers and move
to new, low-density areas in
the suburbs.AFTER
2017 A housing crisis in the
UK prompts calls for the lifting
of restrictions on new building
on the greenbelts around major
UK cities.2050 The date by which,
according to UN estimates
published in 2014, the urban
population of the world is
set to rise to 6.34 billion out
of a projected total population
of 9.7 billion.THE ENVIRONMENTAL
DAMAGE OF URBAN
SPRAWL CANNOT
BE IGNORED
URBAN SPRAWL
The old city is
submerged in a
far-flung, multicentered,
mostly low-density,
highly heterogeneous
urban region.
Robert BruegmannUS_282-283_Urban_sprawl.indd 282 12/11/18 6:26 PM