Climate Action 2012-2013

experiencing negative economies of aggregation,
suffering from the problems without realising any
of the benefits.
The disadvantage of the traditional model is
that it creates a heavy demand on workforce
mobility, with large numbers of people needing
to travel great distances each day. In the absence
of adequate public transport provision, this need
is naturally addressed by an increase in private
automobile use. This was not a problem for
developed countries in the boom time of cheap
oil prices; it is more of a challenge now that oil
prices are consistently higher than US$100 per
barrel and assumed to be increasing over time. As
a result, many cities now find themselves locked
into an unsustainable model of urbanisation
characterised by motor car dependence,
segmented urban form, segregated land use and
predominantly private interests.
Cities developed in this mode can appear to have
a great deal of trees and vegetation, and properties
with large grounds. However, more greenery
does not in itself make a city green, especially if
the provision of such green space means that the
residents have to consume more fossil fuels to
travel around their sprawling city.
In addition, with this kind of urban planning, as
prices in more desirable residential areas grow,
fewer options become available for affordable
housing; and lower-income workers are forced
to move out of the city. According to UN-
Habitat, in some cities, transport can cost the
poor as much as 30 per cent of their wages. This
is when slums start to appear to fulfil the need
for affordable and accessible housing on land that
is close to employment opportunities. However,
these areas are characterised by poor provision of
basic services, inadequate construction standards,
crowded conditions and a lack of security of
tenure for the residents.
GOOD DENSITY VERSUS BAD DENSITY
Slums and informal settlements are assumed to
be very high in density, with no planning of
buildings and not much area allocated to public
spaces or streets. In the Kibera slum in Nairobi,
as little as 3 per cent of the land is taken up by
streets, compared with Manhattan, New York,
where streets account for around 36 per cent of
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