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Rod Burgess
reason. Where sufficient capital has been available (particularly foreign investment
and loans) the result has been the creation of new ‘global settlements’ based on finance,
high-technology industries, commerce or tourism which show scant regard for
sustainability concerns, particularly energy use. Many cities in search of global
competitiveness have relaxed regulations governing peripheral development in order
to attract economic activity and attempts at rationalising the urban form have been
postponed. Nonetheless, with the strengthening of metropolitan decentralisation trends
and urban sprawl there has been a resurgence of interest in urban containment
instruments to control the evolution of the urban form in a sustainable way—
particularly in green belts, green corridors and ecological reserve areas.
Interest, however, has generally focused on improvements to the urban fabric
and attempts to rationalise the form of the historic or old city with the new in a
sustainable fashion. The use of architectural, planning and design elements at the
intra-urban and neighbourhood levels to reinforce urban form has often involved
concerted attempts to harmonise the built environment with local and regional
environmental realities.
Urban size
There has been considerable interest in the manipulation of city sizes in
developing countries in recent years. The emergence of a large number of
megacities (with populations of more than 10 million) has been one reason. It is
estimated that 22 of the 26 global megacities in 2015 will be in developing
countries and several of them will have populations of 20–30 million. The
question of the economic efficiency of city size had been discussed extensively in
the ‘optimum city’ size debates of the 1970s (Richardson, 1972, 1977; Segal,
1976), but under the impact of the environmentalist critique it was realised that
this debate had to be revisited.
Debates that had focused on what was the optimum city size for achieving the best
balance of agglomeration economies and diseconomies now had to consider the
environmental implications of city size—particularly resource use, waste generation
and disposal and the generation and displacement of environmental externalities.
Although the debate was frequently obfuscated by the failure to distinguish
between the problem of primacy and the problem of size, attention focused on the
scale and intensity of the environmental impacts of very large cities. It was argued
that even with existing population size, consumption levels and inequalities,
many megacities were already exhausting their environmental support capacity,
with water consumption exceeding the replacement capacity of primary sources,
the destabilisation of ecosystems, and air pollution levels that were highly
injurious to human health and safety (Atkinson, 1993). Given these trends, it was
highly unrealistic to believe that further market-led urban growth could continue
up to the point where negative environmental externalities made it no longer
profitable for producers to locate in the city. The bigger the city, and the higher its
levels of consumption, the greater would be its ecological footprint. Lack of
access to peripheral greenery and the effect on agricultural production were two
other concerns. The issue of whether city size had a bearing on levels of energy use
and carbon emission rates was less clear.
These arguments are growing in strength but action on them in developing
countries has been rare, in part because of the sheer difficulty of devising effective
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