Cities can be forbidding places. They are full of asphalt and concrete, noise, pollution, and vibration. Dust and litter accumulate along streets and public spaces. Traffic, factories, refineries, and power plants produce dangerous emissions into the surrounding air and water. Community values are weakened, and citizens feel insecure, threatened and unsafe. These conditions pose serious threats to the physical and mental health of urban citizens, and many species of plants and animals can no longer exist in the modern urban environment.

With an estimated 50% of the world’s population living in urban areas, cities have become the engines of modern society, the centres of economic, political, social and cultural activity, and magnets that attract the rural poor. Beginning with the more developed countries of Europe and North America, and now in Asia, Africa and Latin America, cities are spreading out in all directions, consuming farms and open spaces lying in their path. In the face of rapid growth, public services like water supply, sewerage disposal and power generation have been hard pressed to keep pace with the demand. In this context, sustainable urban management is not only an imperative in improving the quality of the urban environment, but a prerequisite for securing a healthy living environment for Europe’s urban citizens.

The objectives of this module are therefore to:

• Raise awareness of the key principles of sustainable urban management
• Present urban management issues from the scope of the environment, the economy, and society
• Stress the links that exist between sustainable urban management and the improvement of the environmental performance and quality of urban areas
• Set out the nature of the challenges, what action has been taken at the European level, and ideas for addressing the challenges identified

The natural heritage of cities
Cities have been built on areas that were once natural, with trees, waterways and meadows that supported diverse ecological communities. Some of those natural features have survived the spread of concrete. Waterways such as streams, wetlands, lakes and canals remain a bastion of greenery and tranquillity where vegetation, wildlife and humans can co-exist in harmony. Waterways cannot be built upon, so they have remained vital open space, although some cities have drained wetlands and lakes, and have enclosed rivers and streams in concrete conduits. Occasionally, active farms have been by-passed in the growth process and continue their operations, surrounded by housing developments and commercial areas. Other green spaces have been purposely set aside, providing valuable aesthetic, recreational and educational opportunities for people and habitat for wildlife. They are important assets in cities, as they can become the building blocks for the restoration of nature to the biopolis.

Today, many people realise that living in a city need not exclude experiencing the joys of nature. Cities in many countries have taken positive steps to restore the ambiance of natural systems within their urban boundaries. They strive to become a “biopolis,” or an environmentally sustainable city, in which their human and natural populations live in harmonious balance. The city of Metz, France, with its urban heritage thousands of years old, decided during the 1970s to enhance its natural attributes and compliment its unique urban landscape. During the past 30 years, the city has increased its green spaces by 150% to 450 hectares, adding in the process numerous walkways, parks, gardens and the largest pedestrian precinct in Europe.

Urban ecology has become an established field of study in many countries, focusing on the inter-relationship of living things, including humans, in a metropolitan context. Universities have established urban ecology programmes, as students explore the biological systems found in their cities. Many of these students have been surprised at the diversity of species they have discovered.

The importance of trees
Trees and greenery provide more than just aesthetic appeal and space for recreation. They also serve vital environmental and ecological functions. Trees provide shade and cool the air. They provide habitat for numerous species of birds, insects and other wildlife. They clean the air, absorbing all manner of air pollutants, including carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone and particulates. These gaseous pollutants are absorbed into tiny pores in the leaves, and during photosynthesis they are broken down into less harmful substances.

Trees also absorb atmospheric carbon dioxide, storing the carbon and releasing the oxygen back into the atmosphere. This process replenishes the air and also helps to counteract the release into the atmosphere of greenhouse gases, which have been associated with global warming. Carbon dioxide is the leading type of greenhouse gas, most of which are produced by industries, heating systems and transport networks of modern cities. By accumulating in the upper atmosphere, these gases prevent hot air from rising, keeping it near the earth’s surface. This, in turn, has led to a gradual warming of average temperatures which, if left unchecked, can eventually cause drastic changes in global climatic patterns. Polar icecaps will begin to melt, inundating coastal areas; swings in the weather will become more severe, with various areas experiencing increased flooding or drought; and increased flooding will in turn lead to the spread of infectious diseases such as malaria and dengue fever. Ultimately, the effects of global warming could be disastrous. Understanding this threat underscores the importance of trees.

Urban agriculture
As urban development spreads into the countryside, it often bypasses small tracts of farmland that remain in agricultural use. These urban farming activities range from household gardens to small commercial operations of between 200 and 1000 square meters and may include greenhouses. The Food and Agriculture Organisation of the United Nations estimates that about 200 million urban farmers throughout the world supply food to 700 million people. In some countries, as many as two-thirds of the urban households are involved in some form of agriculture. These operations provide food such as fruits, vegetables, meat and fish to the growing urban populations of developing countries. Some farmers raise fish, shellfish and aquatic plants in tanks, ponds and lagoons. Others raise small animals such as rabbits and chickens. In Bangkok, over 60% of the land area around the city is used for vegetable gardens. In Accra, Ghana, urban gardens provide 90% of the vegetables consumed by its residents. Urban agriculture is less common in developed countries, but it occurs there as well. In addition to providing food, urban agriculture is a type of open space in the city--a place where children can observe animals and crop production.

Restoring nature to the city
Restoring nature to the city is not a luxury. It is vitally important to our health and well-being. Our cities must become more liveable places for their human populations and more inviting for wildlife. They should capitalise on their green assets and expand the presence of natural systems found within their boundaries. They can achieve this through a coordinated programme in sustainable urban management that preserves and expands green spaces, protects waterways, encourages urban farming, and develops educational opportunities for children and adults. In addition to providing vital environmental functions, such initiatives can greatly benefit the physical and mental health of the inhabitants. The participation and empowerment of all citizens is vital to the success of any such programme. The following are just a few initiatives that cities can adopt to restore natural systems within their areas of jurisdiction:

Expand green spaces
Cities should develop open space plans that provide for interconnected systems of green spaces: parks, gardens, walkways and stream corridors. They should pursue active programmes to increase the amount of open space within their boundaries. This can be achieved by a variety of techniques, including:

• outright purchase of undeveloped tracts
• gifts and bequests of land
• requiring that a certain percentage of new development be retained as open space
• conservation easements, which restrict the use of land in the future to open space
• urban farms and gardens (see below)

Plant more trees
In addition, cities should adopt programmes for continuous tree planting along boulevards, in parks and along streams. This should be done both for the ecological value of trees and for their aesthetic value. Tree species should be carefully selected for their suitability to the individual area, and consideration should be given to native species, water needs, susceptibility to disease, and other factors. Trees with minimal maintenance requirements would be preferable.

Reduce urban sprawl
Land development affects the demand for transportation, and the provision of transportation facilities changes how land is used. Real progress toward sustainable urban management cannot be made without addressing this interconnection. Designing communities so that the demand for transport is less, discouraging urban sprawl, and supporting more compact communities where people can move more easily from home to work, shopping, etc., is essential in achieving liveable cities with enhanced quality of life for all its citizens.

Take advantage of urban waterways
Rivers and streams are natural corridors that transect many urban areas. They provide a great opportunity for recreation, education and contact with nature. Fishing, boating, and even swimming, depending on the water quality, are common activities along urban riverbanks. Urban waterways are vital urban environmental assets that should be protected and made an integral part of the open space system of a city. Pathways should be provided along stream corridors that connect to other paths in the city’s pedestrian and open space network. Where appropriate, measures should be taken to protect wildlife, such as waterfowl nesting areas, while at the same time providing opportunities sites for passive, nonintrusive observation.

Protect urban agriculture
Urban agriculture is often viewed as a holdover from the past and a use that will eventually give way to development. This view should be re-considered however. Farming and vegetable gardens in cities are valuable assets that can be encouraged and protected through appropriate city policy that supports the existence of urban agriculture and provides for its continuence. Care must be exercised, however, to ensure that public health is not threatened by such practices as the use of pesticides. Organic farming would be a preferable approach for urban areas.

Provide programmes in environmental education for children and adults
Cities are home to about half of the world’s population, and this proportion increases with each passing year. Many children grow up in cities, with little or no opportunity to visit undeveloped natural areas. Cities should provide learning programmes for children as well as adults that take advantage of the green features described above: parks, urban farms and waterways. These programmes should include observation of wildlife and an appreciation of bios in all its forms.

Create green roofs and terraces to absorb carbon dioxide emissions
New concepts in urban design should incorporate natural elements and better integrate humans with the environment, wildlife and greenery. As proposed by the Biopolitics International Organisation since 1985, an extension of the existing roof that allows plant trees and shrubs to grow in a light-weight growing medium, can be an effective strategy to address several environmental conditions facing urban environments, including management of storm water runoff and pollution mitigation. In this context, blue-green algae can be used to reduce greenhouse gas emissions, while creating an additional feedstock for renewable fuel production.

Adopt the bio-assessment of technology
The technology and know-how to prevent further destruction to the environment exist, but they are not applied to their full potential. The Biopolitics International Organisation, since 1985, has maintained that the “bio-assessment of technology” is essential in order to retain the positive aspects of technology that can help to support life on our planet. Clean vehicles, more efficient public transportation based on alternative energy, optimum recycling, heating and cooling technology with the use of low-emmissions/low polluting systems, are a few examples of sustainable technologies which should be incorporated in all sustainable urban management programmes.

Create a Bank of Ideas
The success of sustainable urban management can be enhanced with the participation of every member of society. To be effective in responding to the challenges presented, it is essential to stop reinventing the wheel. Owing to poorly coordinated efforts, valuable time and resources are wasted while damage to the environment persists. The knowledge and technology to prevent further destruction are available, but they have to be disseminated more efficiently. As promoted by the Biopolitics International Organisation, an electronic “Bank of Ideas,” where any interested party may contribute information or opinions concerning sustainable urban management, can promote an expedient transfer of knowledge that will help to harness pollution and environmental deterioration and put an end to wasteful and unethical practices.

Promote bio-culture
Culture is an essential element of a sustainable city. The environment is affected by our culture which is, in turn, shaped by the environment. Bio-culture represents a conscious effort to reach this interdependence. Aesthetic values, music, science, the arts, politics, and economics, can all come together in the struggle for a better quality of life. Bio-culture in the city can provide the needed momentum and life-supporting policies to contribute to the more efficient implementation of sustainable urban management.

Engage the media
The role of the media in the realisation of these initiatives is of the essence. The media coordinate and correlate information, thus shaping and inspiring social and cultural attitudes. The power of the media to influence public opinion, as well as the infrastructure available, can make the implementation of sustainable urban management a reality in every European city.

Cities that adopt a programme of sustainable management with the ultimate goal of zero emissions will reap many benefits, both now and in the future. They will become more attractive, healthful and liveable places; wildlife will return; and the cleansing of pollutants from the air and the absorption of carbon by trees will provide long-term benefits for both humans and wildlife. Restoring nature and culture to the city would be a great step toward the creation of a true biopolis.

References

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