Environmental Engineering Reference
In-Depth Information
4
Energy-Efi
cient Informalisation*
4.1 Introduction: Scarce Resources, Efficient
Practices, Urbanisation and Sustainability
Urbanisation is the leading sector on which humans are working; the
ever-growing population is spreading globally and constantly moving
into cities. Major urbanisation activities are taking place in the developing
world. Over the past 50 years, cities have expanded into the land around
them at a rapid rate. Highways and transport systems have been built,
and valuable farmland has been lost. Globally, urbanisation levels will rise
dramatically in the next 40 years—by 70%, with a population of almost
6.4 billion (UN Population Division 2007). According to the UN-Habitat
2008 report 'The State of the World's Cities 2008/2009: Harmonious
Cities', every day 193,107 new city dwellers are added to the world's urban
population, which translates to slightly more than two people every
second. For the years 2000-2005, in developed nations, the total increase
in urban population per month was 500,000, with an annual growth rate
of 0.54%, compared to 5 million in the developing world, with an annual
growth rate of 2.67% [2].
Cities and urban settlements must be prepared to meet this challenge.
In order to avoid being victims of their own success, cities must search
for ways in which to develop sustainably. A successful city must balance
social, economic and environmental needs; it has to respond to pressure
from all sides.
There are a number of theories that define sustainable urban develop-
ment. In the Western world, there are urban movements that combat
suburbanisation, such as 'new urbanism', smart growth, Transit Oriented
Development (TOD) and sustainable urbanism. They attempt to achieve
more environmentally sustainable urbanism. This urbanism, as specified
by the UN-Habitat (2009), requires that (a) greenhouse gas emissions are
reduced and serious climate change mitigation, and adaptation actions are
*
Most of this chapter is derived from Khalil [1].
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