Green Towns and Cities - Theme Cities: Solutions for Urban Problems - page 138

cessful in new sales growth, will probably lead their competitors to follow a similar
policy. These examples should lead to a significant improvement in ethical practices
and will improve key ingredients in the diet of many people in urban areas, even
though costs may be marginally higher. However there are also other problems as-
sociated with food supplies that developed in the rush to create cheaper and more
modified food over the past few decades. Increasing concern about the over-use
of chemicals in so many products has resulted in some governments, but far from
all, providing more explicit labelling of the origin of food products, while others
insist on labels showing the chemical composition of processed food and the calo-
rie count, although such advances are far from universal. Fears of health problems
from processed food also relates to other consumption practices and have led to new
prohibitions, some at a national level, others only in individual cities, such as the
bans on smoking in public places and other issues discussed in attempts to create a
more healthy city (Chap. 13).

4﻽7 Three Dimensional Green Developments

Until recently, the concept of greening urban places was restricted to horizontal,
ground-level activity. In the last decade serious attention is being paid to seeing
how the upper level areas or vertical structures in buildings can also be made more
green. The best known approach can be seen in the Green Roofs and Green Walls
movements that are reviewed in publications such as the Living Architecture Moni-
tor (LAM 2012 ) and the annual American conference, Cities Alive , that promotes
these ideas, which celebrated its 10th anniversary in Chicago in October, 2012 (CA
2012 ). Until recently roofs and building walls were uni-functional, with the former
protecting buildings from the elements, while the latter acts as a frame to hold up or
contain the buildings. The Green Roof movement seeks to add multi-use green de-
velopments to what adherents to the cause see as the wasted space of a roof, chang-
ing its singular function of only providing protection to the floors below from rain
and weather. However, it must be remembered that in many hot climates with low
rainfall, flat-topped houses were the norm and the roof, protected by surrounding
walls, was used to collect rainfall, funnelling into a cistern, or to dry crops, or were
even places to sleep at night since the area would be cooler than the rooms below
which had stored heat from the day. The contemporary Green Roof movement goes
beyond such traditional practices. The simplest example involves the use of grass
on roofs, again to provide insulation and reduce rain run-off, to the more complex
approach involving the development of gardens on the flat tops of large buildings
in particular. Green Roofs are usually classified into two types, intensive and ex-
tensive, which simply describe whether the soil is deep, or is merely a thin layer.
The Green Roof movement is seen to have many benefits, such as: reducing the
rapid run-off of rain and heat loss in winter; providing a cooling effect in summer
that helps mitigate the heat-island effect of the city; providing more recreational
space; and scenic views for surrounding buildings. In addition, gardens in these