Cities all over the world, in developing countries and in developed
countries alike, continue to expand the area they cover.
Developing countries are seeing a sharp influx of people from
rural areas (agricultural villages) to cities. Most of these
people are making "social moves" in pursuit of opportunities
to work in large cities. Clusters of poor housing units (slums)
are created on the cities' periphery as a result.
Meanwhile, in developed countries, high-income earners and members
of the middle class opt to live in the suburbs, where they build
low-rise houses on expansive lots and enjoy the surrounding
nature. A typical example of this is a city like Los Angeles
that has a low population density and spreads over a wide area.
Satellite cities built in the suburbs of large cities-the so-called
"new towns"-are the product of highly developed railways and
expressways. They are another manifestation of ever-increasing
urban sprawl.
Needless to say, urban expansion is a major reason for the destruction
of nature. The disappearance of farmlands in agricultural villages,
the loss of rice paddies, and the destruction of forests harm
the circulation of rainwater and cause loss of species diversity
found in the ecosystem as a whole.
Developing countries are seeing an explosive growth in population,
and are expanding agricultural land by cutting down forests.
If things are left as they are, there is a danger that by the
time the Earth's population reaches 10 billion, all the forests
on the Earth will have vanished.
To prevent this from happening, we must start now to change
our ways. Before it is too late, we must halt the expansion
in the land area occupied by cities and make them more compact.
A compact city is a city that accommodates as many people as
possible within as small an area as possible. Naturally, the
population density is very high. Advocators of "modern cities"
in the 20th century regarded high-density housing as a bad environment,
tried to create low-density cities with lots of greenery. However,
the age of low-density cities with lush greenery, full of urban
parks benefiting only people, is over.
The only option left for us human beings is to foster symbiosis
between nature and high-density, compact cities. Any form of
architecture may be used in this case: low-rise, medium-rise,
or high-rise. The key is that the city must be high in density
and compact in size.
2. Ecological corridors
In the old days, forests covered the Earth and formed an unbroken
ecological system. However, with the appearance of humankind,
the establishment of cities, and expansion of agriculture, every
component of the Earth's ecological system, such as forests,
lakes and marshland, has now become isolated.
This isolation of ecological systems and the enforced shrinking
of each component are the biggest barriers to maintaining biodiversity.
The most effective way to save this state would be to set up
a network of ecological corridors to connect what have become
isolated ecological islands.
To all species-animals, birds, butterflies, and insects-these
ecological corridors would provide a route for moving and for
interacting with each other, greatly contributing to maintaining
species diversity.
The key is to interconnect mountain forests, woods, rivers,
lakes, marshland, rice paddies and grasslands, and to also create
a network with urban greenery such as river and urban parks,
and roadside trees.
Until now, urban parks and park greenery has been planned only
with people in mind. From here on, however, urban parks and
park greenery must be planned as part of an ecological corridor
that benefits other living organisms as well.
3. Recycling
Back in 1960, I began a movement based on an architectural concept
called "metabolism." This was about creating modules of buildings
and cities that could be changed depending on their "life period."
Here, life period included not only physical durable years but
also social and economic life span. My theory was that, by replacing
parts and recycling them, we can use the overall frame far more
sustainably and for longer periods of time.
This was a revolutionary concept that challenged the conventional
notion that "buildings and cities have an ideal form, and once
this form is achieved, they are eternal." The concept of recycling
the main structure of a building or a city is the foundation
of sustainability. Second is the recycling of urban domestic
wastewater. Of course, large volumes of water are already being
purified, recycled, and used as non-drinking water. However,
in Singapore, where water is in short supply, people purify
domestic wastewater and recycle it as drinking water.
Third is the recycling of industrial waste liquids and materials
that are disposed of after mass production. These include the
recycling of household appliances, cars, audiovisual equipment,
IT and other industrial products; the recycling of architectural
waste materials; and the recycling of refuse, agricultural waste
material, and manure. If a set volume of these items can be
systematically recycled, large-scale recycling plants will become
economically feasible. Therefore, international operations for
the import and export of refuse would become necessary.
Recycling in the agricultural sector is another important challenge
facing developing countries. Livestock manure and agricultural
waste materials, in particular, have major potential as a biomass
energy source. Recycling them, therefore, would serve a dual
purpose.
Fourth is the recycling of rainwater. In the old days, rainwater
followed a natural cycle. It was purified by the soil of mountain
forests and woods, retained in rice paddies, marshlands and
lakes, then slowly passed through rivers to flow into the seawater.
It evaporated once again and fell as rain. Today, this cycle
is not functioning properly.
One reason is the reduction in water-retention capability resulting
from a decrease in rice paddies, marshlands, lakes, and forests.
Second is the increased speed of river flow because of improvements
made to river banks to prevent flooding. Third is the reduction
in forest soil's water-retention capability resulting from the
increased planting in Japan of tree species for specific use
as construction materials, such as Japanese cedar and cypress.
Water is best retained in soil where deciduous bushes and trees
grow.
By far the most important reason, however, is that, because
city streets are covered by waterproof cement, concrete, and
asphalt, rainwater does not penetrate the soil underneath. Instead,
all the water passes from the roads' drains to rivers, and then
directly released into the ocean. Reconstructing this recycling
system is one requirement for creating a sustainable city.
4. Alternative energy
We now rely on petroleum energy for every aspect of our lives.
However, we need to depart from this practice as quickly as
possible.
All forms of energy-nuclear power, hydropower, or thermal power
generation using coal gas-create environmental problems. Sources
of energy with the greatest future potential are biomass, solar
panels, and wind power. Biomass can be used in developing countries,
and developed country while solar panels and small, vertical-shaped
wind power systems are fully employable in city areas. Governments
should actively propose measures and programs to promote their
use.
5. A sustainable transport system
Automobile-based traffic and transportation are developing rapidly.
The use of cars in cities not only expands the urban landscape
into suburban areas; it is the biggest cause of traffic congestion
and air pollution.
I believe that we must revive an urban transport system that
is comfortable for pedestrians and bicyclists alike. If a compact
city were to be constructed, public transportation systems such
as monorails and LRTs would become fully profitable and people
would use cars less and less.
It is an urgent task to design cities that can systematize,
in a well-balanced manner, modes of transportation such as walking
and using bicycles, automobiles, buses, subways (LRT), and ships,
and which can introduce such systems.
News
& Events
Maritta Koch-Weser gives an International Perspective on the evolution of Civil Society engagement in environmental affairs at the 3rd Arab Reform Forum at the Bibliotheca Alexandrina, Egypt, March 1-3, 2006.
Earth3000 President Maritta Koch-Weser joins Founding Board of Directors of the Planet 2025 Fund a global community investment program of the Eco-Insurance Initiative
