Energy & Water Efficient Eco-Homes, Low Polluting Eco-Vehicles, Waste Reduction, Reuse & Recycling Contribute to
Sustainable Urban Development
1. The Concept of Sustainability
The word ‘sustainability’ for urban ecosystems (the manmade ecosystem on earth) is inspired by the concept of Sustainable Development conceived by the ‘World Commission on Environment and Development’ (WCED) and published in the report of Club of Rome- ‘The Blueprint for Survival’ and Bruntdland Commission Report (1987) ‘Our Common Future’. It defined sustainable development as –
‘Development to meet the needs of the present without compromising with the abilities of the future generations to meet their own needs and a system of stable economic development that should improve the total quality of life on earth now and in the future too, while maintaining the social and ecological integrity of the earth upon which all life depends’.
The concept of urban sustainability is about efficiently using the available natural resources for urban development and for the welfare of the urban human society e.g. land, soil, water, food and energy and also safely disposing the waste generated by them. Cities must provide secure power supply, clean water, environmentally sound sanitation, safe streets, and reliable transport and communication links to achieve the goals of sustainability. Without proper urban planning, certain infrastructure investment can create urban sprawl, while lack of infrastructure investment can lead to unserviced informal human settlements, waste and pollution, poor environmental sanitation which are sources of high morbidity and mortality. However, it is not possible to install a full-service urban infrastructure in every country, rich or poor, because their inhabitants do not have the financial capacity to pay for it.
Rapid urbanization (proliferation of cities) has helped the world economy, but has degraded the ecology. It has given birth to social and environmental problems. No city in world today is environmentally sustainable. There is increasing environmental pollution, mounting wastes, and health problems emanating from air and noise pollution. Increasing urban growth creates more demands for land, housing, transport, food, water, power, sanitation, education and health facilities, thereby putting more ecological pressure on the already stressed urban ecosystem. To fulfill these requirements, cities go on absorbing the nearby suburbs and the rural landscape situated in the fringes and push the hinterland further. In the process it eats away the valuable fertile lands, thereby reducing the productivity further.
The Expanding ‘Ecological Foot Print’ of a City : Serious Consequences for Urban Sustainability
Ecological foot print (EFP) is the area of the landscape (land, water and vegetation) around every human settlement (urban or rural) in world which it requires to cater the survival needs of its population. Quantitatively, EFP is an estimate of the average area of productive land and water required to maintain a given population’s resource consumption and waste generation. It is the way to convey the ‘environmental cost of living’ of a given population in an area.
The landscape around the cities provides following social and environmental services to the urban society -
1). Supply the vital commodities for their survival e.g. food (from farms), water (from catchments areas, surface and groundwater water sources) and oxygen (from the green plants which they generate by photosynthesis in light) in the breathing air;
2). Absorb and assimilate all the excreted products (garbage & sewage including human excreta and the gases (specially the CO2) given out from breathing and burning of fossil fuels generated by them in course of living;
3). Provide space for landfill to safely dispose all the wastes (domestic and industrial) generated by them in the womb of Mother Earth;
London city which physically occupies 170,000 hectare has an ‘ecological foot print’ of 21 million hectare which is 125 times of the city’s area. Currently, over two-thirds of London’s municipal wastes are exported out of the capital to the surrounding regions. Average North American city with population of over 650,000 will need 30,000 square km of land to service its needs (UNEP Report, 2005).
2 (a). The Image of a Sustainable City (Ecologically Balanced)
A sustainable city is one-
- Where it is pleasant and safe to walk to shops, parks and schools;
- Where streets are safe to walk and cross, and cycle on in separate bicycle lanes;
- Where there is enough parks and green areas for children to play and elders to walk;
- Where work is not far away and easily reached by bus or bi-cycle ;
- Where the frequency of public transport is good and more ‘park and ride’ facilities;
- Where public transport is integrated with housing colonies and shopping facilities;
- Where buses move quickly in designated bus lanes and get priority at traffic lights;
- Where there is no traffic congestion and vehicles move smoothly;
- Where there is no black smoke emitting and noisy vehicles running on roads;
- Where the sky is clear all times and no smoke or haze;
- Where there is no sight of municipal waste on road or at any street corner;
- Where clean water is always available for the residents;
- Where electricity is available round the clock without any interruption.
- Where residents generally enjoy good health and comfortable life.
(b). The Image of an Unsustainable City (Ecologically Imbalanced)
An unsustainable city is one-
- Where smoke is visible in the air, and the breathing air has typical smell;
- Where municipal wastes are visible and lie scattered or piled in street corners;
- Where streets are congested with smoky vehicles moving in haphazard manner;
- Where people honk horns frequently and shout on traffic;
- Where walking and cycling on streets are unsafe;
- Where water and electricity supply is often interrupted throughout the day;
- Where frequency of public transport is poor and hard to get;
- Where green area is a rare sight;
- Where potential risk to resident’s health from waste and pollution is always higher.
3. Urban Proliferation and the Pace of Urbanization
World cities are growing unsustainably at an unprecedented rate today- by 60 million people each year (280 thousand people born every day). In the 19th century only 3 % of the population lived in cities and by the end of the 20th century 47 % i.e. almost half of the world population were concentrated in the urban areas. Urban development has been exceptionally rapid in the last two decades- 47 % in 2000 as compared to only 10 % in 1980 and 1 % in 1940. It is expected to rise to over 61 % (UNHS Report, 1996 a).Majority if this has occurred in developing countries where there are 213 cities of more than a million people, and some 20 of them with over 10 million mark. It took London 130 years to increase its population from 1 million to 8 million, but Mexico City grew by as much in just 30 years- from 1940 to 1970 (UNEP Report, 1992).
According to United Nations Commission on Human Habitat there are 23 mega-cities in world today with population soaring more than 10 millions in each and 19 of them are located in the developing countries of the South. This will continue and by the year 2025, the world is expected to become home to 100 mega-cities with a population of more than 5 billion.
Urban Population (in %) Urban Population Growth Rate (in %)
1980 2000 2020 1980-85 2000-05 2020-25
World 39 47 57 2.6 2.2 1.7
Developing Countries 29 41 52 3.8 2.9 2.1
Developed Countries 71 76 81 0.9 0.5 0.3
Source: WRI, UNEP, UNDP, WB (1998)
If cities continue to grow in typical New World style grid pattern, people would use cars, especially if there is greater distance between the residence and the work places / shopping centers. Global population of automobiles is rising rapidly and is expected to pass 1.1 billion mark by 2020. In most world cities today vehicular pollution levels often exceed the recommended WHO (World Health Organization) guidelines. In Mexico City pollution levels exceeded WHO standards on almost all days and doubled on 192 out of 365 days in 1991. Cities like Los Angeles (USA), Beijing (China), London (UK), Bombay and New Delhi (India), Colombo (Sri Lanka), Sao Paulo (Brazil), Milan (Italy), Miskole (Hungary), Tulcea (Romania), Bangkok (Thailand), Manila (Philippines), Tehran (Iran), Lagos (Nigeria), Krakow (Polland) seems to have become ‘gas chambers’ locked inside gigantic bags of pollution. Cubatao city near Sao Paulo in Brazil is known as ‘valley of death’ (UNEP Report, 1992).
Mega-Cities in World ( Projected Population During HABITAT-III, 2015)
Urban Agglomeration Population (in thousands)
Lagos (Combodia) 10,287 24,437
Cairo (Egypt) 9,656 14,494
Tokyo (Japan) 26,836 28,701
Bombay (India) 15,093 27,373
Shanghai (China) 15,082 23,382
Jakarta (Indonesia) 11,500 21,170
Karachi (Pakistan) 9,863 20,616
Beijing (China) 12,362 19,423
Dacca (Bangladesh) 7,832 18,964
Calcutta ((India) 11,673 17,621
Delhi (India) 9,882 17,553
Metro Manila (Philippines) 9,280 14,711
Sao Paulo (Brazil) 16,417 20,783
Mexico City 15,643 18,786
Rio de Janeiro 9,888 11,554
New York (U.S.A.) 16,329 17,636
Los Angeles (U.S.A.) 12,410 14,274
Source: UNCHS (1996)
Causes of Urban Proliferation and Future Projections
Several factors contribute to the ‘rural-to-urban’ migration. The most common is rural unemployment, shortage of basic services like health, sanitation and education in rural areas. Land degradation and serious shortage of arable land for agriculture has been another important reason of urban migration in several developing countries. Africa will experience the highest urban growth rate – an average of between 4.3 to 4.5 %. Latin America already urbanized will not have such a large increase. Absolute growth will be greatest in Asia, where cities will have over 210 million people in this decade. Urban growth occurs from the ‘natural increase’ of the urban population as well as ‘rural-to-urban migration’ and the factors vary throughout the world. In Africa urban growth is caused largely by rural-to-urban migration.
It is important to note that even the rural and remote areas in Australia lack adequate health and medical facilities. The ratio of doctor to patient is 1 in 1500 people in rural Australia. Large number of people from rural Australia have migrated to the cities particularly concentrating in Sydney, Melbourne and Brisbane.
Industrialization also Leads to Urbanization
Industrialization has also contributed significantly in urban proliferation. Industries are often located on the fringes of cities. More and more people from rural areas migrate to cities to find jobs in industries and settle down closer to it. Industrial development in cities has long been associated with a range of environmental and human health hazards.
4. Environmental Factors Leading to Unsustainable Cities
Increasing Greenhouse Gas Emissions from Modern Homes
Every house in a city emits greenhouse gas predominantly carbon dioxide (CO2) either directly or indirectly through the use of energy (gas or electricity and even fuelwood) for indoor activities like lighting, heating, drying, cooling, cleaning, washing and cooking. Activities in kitchen emits maximum greenhouse gas in a house. Use of electronic instruments and electrical appliances and lawn mowing activities (in most developed countries) also consume energy and emits greenhouse gas.
Increasing Indoor Pollutants (Chemicals and Pathogens) in Modern Homes
The deteriorating quality of indoor air by in-house air pollutants is a major cause of concern today as people specially children, spend considerable period of time indoor. A study indicates that the pollution levels in the modern homes can be up to 20 times higher than outside. As modern buildings are being made more energy efficient, the problem is worsening. The building envelop is more tightly sealed to stop infiltration of outdoor air. Carbon monoxide, oxides of nitrogen, volatile organic compounds are higher in modern urban homes. Many common building materials such as solvent based paints, carpets, textiles and furnishings, furniture and fixtures may contain volatile organic compounds (VOCs) the fumes of which are harmful to health of residents. Some building materials give off radon and asbestos particles.
There are also ‘aeroallergens’ (dust mite particles/faeces, moulds) and the tobacco smoke. The air-conditioning systems in buildings have been found with Legionella bacteria and several incidences of lung related ‘legionairre’ disease are reported every year in Australia. Swimming pools in modern homes have also become source of health hazard. ‘Cryptosporidiosis’ caused by Cryptosporidium was reported in Australia.
Following factors in modern homes can lead to indoor pollution-
1. Many common building materials such as paints, carpets, textiles and furnishings that contain PVC, styrene, epoxy resins, glue or varnish solvents may give off harmful fumes;
2. Unflued gas stoves in our modern kitchen release nitrogen dioxide (NO2) and carbon monoxide (CO).
3. Cleaning chemicals in homes release air-toxins. Air freshners in the toilets and bathrooms releases VOCs.
4. Chloroform is formed when the hot chlorinated water evaporates.
5. Synthetic carpets can contain chemical stain resisters, pesticides, solvent-heavy glues and VOC laden underlayers.
6. Unflued gas heaters release nitrogen dioxide and carbon dioxide. Wood heaters may release carbon monoxide if burning inefficiently.
7. Chipboard and plywood furniture releases formaldehyde.
8. Dry-cleaned clothes and curtain treated with stain resisters give off VOCs.
9. Fibre-glass based house insulation gives off VOCs.
10. Solvent based wall paints release VOCs. Paints have been found to contribute 80 % of the air pollutants. They contain dangerous chemicals like glycol, benzene, ethers, formaldehyde and ammonia. (Some paints release toxic fumes for up to 7 years after application).
11. Toxic gases including benzene can seep into houses from the adjoining motor garage specially during the cold start of vehicles.
Increasing Degradation of Arable and Fertile Land
Increasing urban growth creates more demands for land, housing, transport, food, water, power, sanitation, education and health facilities, thereby putting more ecological pressure on the already stressed urban ecosystem. To fulfill these requirements, cities go on absorbing the nearby suburbs and the rural landscape situated in the fringes and push the hinterland further. In the process it eats away the valuable fertile lands, thereby reducing the productivity further.
Increasing Biodiversity Erosion
In several developed and developing countries of world urban expansion has resulted in removal of trees and bushes and have eroded the local biodiversity. Australia is a prime example. It is a highly urbanized nation with about 85 % of its population living in towns and cities which are mostly located in the coastal areas.
Australian cities consume over 1200 square meters of land per person which also includes the old growth forest lands. Although these settlements occupy less than 1 % of the country’s land area yet they significantly affected the terrestrial and the marine ecosystems and their biodiversity. CSIRO, Australia has estimated that 60 % of the Queensland’s rare, threatened or endangered plants in the old growth forests lie in the urban growth area of the State’s South-East.
Growing Vertical Cities : The Heat Islands on Earth
Population explosion in cities and the consequent reduction of land per unit of the growing human population have forced the urban developers and planners to look towards the sky for developing ‘vertical cities’ disregarding the ecological consequences of such housing development. The culture of ‘sky-scrappers’ and high-rise multistoried buildings, where human beings have been lodged into ‘cages’ have created several health, environmental, social and psychological problems. These ‘concrete jungles’ made of stones and bricks dot the earth everywhere replacing the ‘natural jungles’ of trees and twiners. They have become the ‘heat islands’ on earth, absorbing solar radiation in the day time and releasing heat back into the space in the night.
Deterioration in Quality of Municipal Water Supply
Quality of municipal water supplied in urban homes in most developed countries are generally good but conditions are deteriorating.
Nearly 300 UK water supplies were found to be contaminated with pesticides above the WHO limits. (UNEP Report, 2004).
With the improved analytical techniques, sometimes microorganisms like Giardia lamblia and Cryptosporidium parvum have also been reported in public water supplies. Giardia was reported in Sydney water supply sometimes in the 1990s.
Also, disinfecting public water supplies with chlorine has been found to form volatile halogenated derivatives which are carcinogenic. Disinfection is now being done by UV rays. Some countries are using ‘membrane filtration technology’ (MFT) by ‘reverse osmosis’ which gives out clean disinfected water.
In developing countries, the quality of water supplied in urban homes has deteriorated over the years as water becomes a scarce commodity and consumption rises. Giardia is very common.
Deterioration in Quality of Urban Air
Urban air today contain a frightening mix of toxic chemicals like carbon monoxide (CO), oxides of sulphur (SOx) and nitrogen (NOx), reactive hydrocarbons (volatile organic carbons (VOCs)), total suspended particulate matter (TSP), heavy metal lead and organic compounds resulting from the automobiles. Diesel vehicles emit over 100 microparticles several of which are carcinogenic. Particulate matters also provides surface for the condensation of other air pollutants such as sulphur dioxide, which combined produce greater health and environmental effect. The oxides of nitrogen and the VOCs undergo photochemical reaction to produce more deadly secondary pollutants called ‘tropospheric ozone’(O3) and the ‘periacetyl nitrate’ (PAN). Ozone is the major component of this ‘photochemical urban smog’ which plagues several cities of world today including Sydney and Melbourne in Australia. Smog contains about 10,000 - 30,000 ppm of carbon monoxide (CO), 100 – 400 ppm of nitrogen dioxide (NO2), 600 – 3000 ppm of hydrocarbons (HCs), 50 – 150 ppm of ozone (O3) and 50 – 250 ppm of periacetyl nitrate (PAN).
Air Quality in Some Cities of Developing Countries (Dust and Suspended Particles)
Most Polluted Cities (mg / cum of air ) Least Polluted Cities (mg / cum of air)
Mumbai (India) 500 Singapore 30
Colombo (Sri Lanka) 475 Tokyo (Japan) 46
Delhi (India) 460 Taipei (Taiwan) 51
Calcutta (India) 460 Osaka (Japan) 55
Beijing (China) 410 Yangon (Myanmar) 75
Karachi (Pakistan) 380 Seoul (South Korea) 85
Bangkok (Thailand) 300 Hong Kong (China) 94
Shanghai (China) 300 Jakarta (Indonesia) 128
Macau (China) 229 Kuala Lumpur (Malaysia) 130
Bangalore (India) 200 Hanoi (North Vietnam) 130
WHO Permissible Limit = 200 mg / m (From Publications of UNEP and WHO, 1998)
Increasing Noise Intensities in Urban Environment
Increasing noise intensity is a growing phenomenon all over the world but more in the cities of developing countries much due to the exploding population of both humans and the automobiles. Man and the machines made by him is creating chaos in the environment. Although the modern generations of automobiles have become much quieter but the massive increase in their numbers have neutralized all the technological achievements of a soundless automobile. The ugly culture of ‘honking horns’ in the cities of developing countries is a ridiculous feature.
In the developed countries faster moving vehicles within the city suburbs with speed limits ranging between 60 to 80 km per hour, and the 100 km limits freeways and motorways passing through the middle of the city connecting the four sides of expanding city limits- north, south, east and west have become major source of noise pollution. With increasing number of vehicles per person the noise intensity has increased significantly. In one of my surveys made in Brisbane, the residents living around 100-500 meters from the passing freeways and motorways are highly uncomfortable especially during the night hours. People living around the Pacific Motorway going to Gold Coast from Brisbane are always complaining and protesting against this increasing noise pollution.
WHO standard and acceptable limits of noise levels for residential areas in the cities is between 45 - 50 dB (decibel), 1 dB being the threshold for hearing and 140 dB for pain. Most cities including those in Australia has crossed this barrier long before and have become noisy. Noise levels of cars at 20 ft is between 70 - 80 dB, that of big trucks over 100 dB, sub-way trains 95 dB, dish washer in home is about 65 dB.
Noise pollution in cities is working like a ‘slow poison’ for residents. Headache, tinnitus (ringing in ear), presbycusis (a kind of deafness), emotional distress, fatigueness, sleeping disturbances, high blood pressure and cardiac problems are attributed to increasing noise intensities in the city life.
Recent studies have indicated that prolonged exposure to high noise intensities can cause miscarriages, still-births and physical deformities in the new born. Pregnant mothers if exposed continuously to high noise levels may deliver prematurely. Even the growing human foetus is not safe from the high noise intensity. Another study suggest that people living in the high noise areas of the city has the tendency to become more aggressive.
High Energy and Water Requirements to Sustain the Urban Population
Cities, specially the vertical cities have become highly water and energy intensive. Exceptionally large amount of water is needed for cultural uses like bathing (shower and bath tub), washing, cleaning, toilet flushing and gardening in urban homes. The modern home appliances like dishwasher and the washing machine consume huge amount of water and also energy, though they have become energy efficient. More and more energy is needed to boost water, lift the people up, illuminate and fan their caged premises and manage their waste. Lifts, escalators and water boosters are high energy consuming devices in multi-storied buildings.
Urban food supply is also highly energy intensive. Their food is transported from several kilometers away from the farms in the rural areas. Urban people in the developed countries mostly consume ‘processed food’, ‘take-away foods’, ‘canned and bottled foods’. They consume high energy in processing and packaging and also create more waste, which further require energy for their safe disposal. City dwellers often have to travel large distances for work and shopping and need some form of transport which require energy.
Increasing City Metabolism (Resource Consumption and Waste Generation)
Cities have become major ‘centers of consumption and waste generation’ all over the world. An average urban household has become a ‘consumption point’ where tones of food and pure water are imported from several kilometers apart, used and disposed off into the local ecosystem as waste and excreta. In fact a city ‘consumes’ as well as ‘produce’. This is called ‘urban metabolism’. City use some 75 % of world resources and release a similar proportion of wastes.
According to UN Population Fund Report (1990), a city with one million population consumes 2000 tones of food and 9,500 tones of fuel, generating 2000 tones of solid wastes (garbage and excreta) and 950 tones of air pollutants; consumes 6,25,000 tones of pure water and secrete 5,00,000 tones of sewage. UNEP (1996) worked out the urban metabolism of London city. Everyday London dispose off some 6,600 tones of household wastes.
Metabolism of London City (Population 7 million - 1996)
Resource Consumption Tones Per Year
1. Fuel and Oil Equivalent 20,000,000
2. Oxygen 40,000,000
3. Water 1,002,000,000
4. Food 2,400,000
5. Timber 1,200,000
6. Paper 2,200,000
7. Plastics 2,100,000
8. Glass 360,000
9. Cement 1,940,000
10. Bricks, blocks, sand & tarmac 6,000,000
11. Metals (Total) 1,200,000
Waste Generation Tones Per Year
1. Industrial and demolition wastes 11,400,000
2. Household, civic and commercial wastes 3,900,000
3. Wet and digested sewage sludge 7,500,000
4. Carbon dioxide (Greenhouse gas) 60,000,000
5. Sulphur dioxide ( Acid rain gas) 400,000
6. Nitrogen dioxide (Smog forming gas) 280,000
Source: UNEP Report (Our Planet Magazine) Vol. 8; No. 1 (1996)
Urban Waste Generated in Some Developed Countries (In tones)
Country Annual Generation Country Annual Generation
USA 20,00,00,000 Sweden 25,00,000
Canada 1,26,00,000 Switzerland 21,46,000
Australia 1,00,00,000 Denmark 20,46,000
Spain 89,28,000 Norway 17,00,000
Netherlands 54,00,000 New Zealand 15,28,000
Belgium 30,82,000 Finland 12,00,000
Source: Blueprint for Green Planet ; Dorling Kindersley, London (1987)
5. Social Factors Leading to Unsustainable Cities
There is a social dimension of urban sustainability. A city that prospers economically, but fails to distribute the wealth with some degree of equity, runs the risk that it disintegrates into a civil war between the haves and have-nots, a war in which both sides are the losers. There is an increasing social tensions and conflicts, drug abuse, crime and violence due to urban congestion in several developed and developing countries. Several cities and the U.S. is suffering from such problems. Drug abuse and related crimes are also increasing in Sydney.
Urban Slums : Breeding Grounds of Anti-Social Activities in Cities
Not only are we living in an increasingly urbanized world, we are also experiencing an urbanization of poverty and along with it, increasing feminization of poverty. An estimated 25 % of urban populations- over 400 million people live in poverty. They suffer disproportionately from failures in urban services, from safe water supply and safe waste management provisions to accessible urban transport. According to UN Commission on Human Settlements 40 % of the world population live in urban slums. This is mostly in the developing countries. The slum dwellers regularly encroach into the urban ecosystem and pollute both the physical as well as the social environment. They are like ‘ulcers’ in the stomach of a city, and have become major breeding grounds of anti-social activities, crime and violence in the cities.
Increasing Health Risks to Urban Dwellers
Urban people in both developed and developing countries suffer from several mental and physical health problems today. Respiratory and lung related problems like asthma and bronchitis, sore throat, clogging of sinuses and running nose, loss of appetite and digestion related problems, hypertension and cardiac problems, eyes and skin problems, fatigueness and diabetes are on the rise in cities all over the world, and this is attributed directly or indirectly due to the urban waste and pollution.
TOWARDS SUSTAINABLE CITIES : THE CRUCIBLES OF
Cities are centers of global finance, industry, culture and communication, exchange of information, learning and production, opportunities and freedom of options and the enhancement of a richer cultural life. Cities are ‘engines of economic growth and crucibles of development’. It is an ‘intellectual think tank’ for the society. In cities, economic factors are translated into actions of society and other social behaviors for better or worse. Economic policy, decisions of government, their success or failures, are immediately noticeable in the cities. In other words cities reflect the turmoil of the period mankind is going through.
The growth of large cities, metros and even ‘megacities’ will continue. By the year 2025, the earth is expected to become home to almost 100 megacities with a population of more than 5 million (UNEP, 1996). Eighty of these urban agglomerations will be located in developing countries. Cities are our common future and there is no road back to pre-industrial society. There is also no choice in the face of rapid population growth in a world in which population is growing by 280,000 people per day. The challenge is how to organize a large and ecologically compatible urban infrastructure in such a way that allows efficient use of energy and water resources, safe management of waste, sustainable housing development, job opportunities, commerce and trade, mobility and leisure.
Some European cities like Zurich and Basel in Switzerland, Copenhagen in Denmark, Freiburg, Karlsruhe, and Bologna have provided the models of sustainable cities which many other cities of world are emulating.
UN Conferences on Sustainable Urban Development
The first United Nation Conference on Human Settlements (HABITAT – I) was held in Vancouver, Canada, in 1976, which focused mainly on the poor ‘living conditions’ in the developing countries of Africa, Asia and the Latin America and how it can be made sustainable for the inhabitants. The second UN Conference on Human Settlements (HABITAT – II) also called the ‘City Summit’ was held in Istanbul in 1996. This time the focus was on specific issues of ‘environmental sanitation and health of city dwellers’, ‘piling waste and pollution’, ‘availability of safe food and clean water for the city dwellers’, ‘proliferation of urban population’, ‘urban poverty and hunger’, ‘disease and drudgery’, ‘availability of space’, ‘crowding and congestion’, ‘soaring urban unemployment’, ‘status of women in the cities’, and ‘increasing anti-social activities such as drug abuse and crime in the cities’ in both developed as well as in the developing countries. By the time of HABITAT-III in 2015, 27 cities will have passed 10 million mark, 516 cities will have passed the 1 million mark and the urban population will have passed the 4 billion mark.
The ‘Earth Summit’ held in 1992 in Rio de Janeiro, Brazil, also recognized that sustainability in urban development was key to the global sustainable development program for the human society. Conference on ‘World Commission on 21st Century Urbanization’ was held in Berlin in July 2000. Making the world cities sustainable, was the key theme of the conference.
(1). The Policy Measures for Development of Sustainable Cities
a). Building Sustainable Homes : The Concept of Eco-houses in Eco-cities
For sustainable cities, we need designs and materials for the development of sustainable homes and settlements. These have been termed as ‘eco-houses’ and ‘eco-colonies’. Conservation of water and electricity and their efficient use is the key to development of a sustainable home. The concept of an eco-house and an eco-city is based on -
(1). Use of environmentally friendly, durable and renewable, long lasting building materials that are low maintenance and free of toxins, and would reduce our dependence on baked earthen bricks, timber, cement and steel (whose procurement from earth entails severe environmental damage), and increase the use of ‘recycled waste products’ as building materials.
(2). Use of energy efficient electrical appliances & instruments in homes such as automatic lighting control system (ALCS), compact fluorescent, low voltage tungsten halogen and sodium lamps etc. They save electricity from 70 - 80 %. The modern white goods such as refrigerators, freezers, washing machines, clothes dryers, dishwashers and air-conditioners use 75 % less energy than previous models. They have been given an energy efficiency star ratings on a scale of 1 to 6 stars, 6 star being most energy efficient. Currently no appliance have been given higher than 4.5 ratings. Improvements are in progress. Since 1980, US has conserved energy 4 times by efficient energy use technology (EEUT) in homes and appliances, thus saving for the consumers and industry $150 billion a year (UNEP Report).
(3). Use of water efficient appliances - taps, showers, cisterns, dishwashers and washing machines. Front-loading washing machine with a ‘AAAA’ water conservation rating and a high star energy rating use less water and energy. The average household can save around 16,000 litres of water a year using a dishwasher rather than washing up three time a day under tap water. Beside hot water savings it also save detergent, scourers, tea towel cleaning and gloves etc.
Eco-Design for a Sustainable Home
Housing designs with devices for ‘conservation of water and electricity’ and reduce the consumption of energy for cooling and heating, while also maximize the use the solar radiation and natural air current for ventilation.
1). The kitchen and bathroom wastewater could be redirected into lawns, toilets and urinals, instead of directly into the sewers.
2). Wash-basins, bath-tub and shower waters can be reused to fill the cisterns of flush toilets. This can be achieved by using low level cisterns and designing toilets few steps below the floor level.
3). Swimming pools in homes are in fact fun. They are not an environmentally friendly addition to homes. Swimming pools are neither water, nor energy efficient. They consume precious land, water and require large amount of chemicals in maintenance.
When designing and building a sustainable home, the greatest economic and ecological gains are in planning and orienting homes in the environmentally friendly manner. Orienting main living areas to the warmer northern side and bedrooms to the cooler southern side; placing laundry, garage, bathrooms and storerooms to face the hotter afternoon western sun; where possible minimizing windows on the western side; planting native shade trees especially towards the western side of house for natural cooling; positioning doors and windows so as to provide cross-ventilation, catch breezes and channel air through each room can save tremendous energy. Such will be most energy efficient eco-house.
Infrastructure for a Sustainable Home in a Sustainable City
1). Installation of ‘AAAA’ water efficient taps and shower to reduce the flow of water. Installation of a 3 liter / 6 liter ‘dual flush’ toilet. This will significantly reduce the loss of pure drinking water every time while using the toilet for urination.
2). Using ‘fluorescent lights’ in homes to reduce energy consumption in lighting. It has 8 times longer life than ordinary light bulb and may be costly but the cost is repaid back in terms of reduced electric bills. An energy efficient fluorescent light with an output of 60 watt light consume electricity equivalent to 18 watt only. A fluorescent lamp in its lifetime has been calculated to prevent emissions of nearly a ton of greenhouse gas through energy savings. Low voltage downlights are not energy efficient.
3). Installing insulated ‘skylights’ to let in natural light especially the one which only allows light to come in and not heat.
4). Installing a ‘double bowl kitchen sink’ in homes, so that the second sink can be used to rinse raw vegetables and dishes for washing and cleaning rather than under the running tap water.
5). Installing a ‘rainwater tank’. Using rainwater for garden, toilet and hot water system can help reduce the use of main water supply by 60 % per year which is significant. Using a rainwater tank has flow that benefit the whole city, the environment and the urban society. This include reducing the size of water distribution pipes and the amount of energy needed to operate city water supply system. It will also reduce the need for new dams, reduce stormwater run-off that causes erosion and flooding.
6). Installing a ‘gas cooking stove’ for cooking. It has significantly lower greenhouse gas emissions as compared to electric stove, provide better heat control and lesser heat loss during cooking. Fan-forced oven are about 30 % more efficient than conventional stoves, which waste up to 90 % of the energy they use.
7). Installing a ‘solar’, ‘gas’ or ‘heat-pump’ hot water system. Water heating accounts for at least 30 % of all energy consumed in homes and 25 % of all greenhouse gas emissions produced by homes. There is much less emission in gas system and none in the solar system. The systems should be positioned as close as possible to the point of most frequent use- usually the laundry, bathroom and kitchen and the outer pipes must be properly insulated.
8). Installing a ‘reverse cycle’ split air-conditioner which both heats and cools. While heating, it consume far less energy, produces only one-third of the greenhouse emissions of standard electric heaters.
9). Installing ‘solar photovoltaic (PV) electricity system’. The systems are made of solar panels which are placed on the roof tops. PV system also interacts with the main electricity supply grid.
Tall Buildings in City Centers
Since tall buildings tend to entrap noise and air pollutants, this should be discouraged around city centers. Lifts in tall buildings must start from second floor and part of the electrical energy spent in lifts should be recovered by the movement of the ropes through generators fitted at base. Wherever possible, tall buildings should be such designed and so located, so that the prevailing wind and air current blow across them and do not get obstructed by them. This would disperse and blow away the vehicular pollutants from the city areas and reduce the intensity of traffic noise.
(b). Better Land Use Pattern: Integrating Housing Colonies with Sustainable Transport System and Improving the Efficiency of Public Transport
An effective land use pattern, integrating the housing colonies with the transport system, is the key to development of sustainable cities. Government in developed nations have long recognized the importance of societal gains and not individual profit in the ethical use of space for urban development. Unfortunately, this ethical principle in land use has not been embraced in most developing countries. Compact urban centers, positioning new developments within cycling or walking distance of public transport (metro rail or bus) stops, greater facilities for park & ride, bringing together places of living with work and shopping centers is a sustainable planning.
We must invest sufficiently in public transport specially in the metro rails. Switzerland, Germany, Hong Kong and Singapore have invested much in public transport and followed a more sustainable path. Singapore is managing very efficiently through area licensing scheme levying a fee on vehicles entering the city centers except the buses, commercial trucks, and cars carrying 4 or more persons. Single occupant cars are not allowed in the city centers. Expanded bus services, heavy parking charges and higher car taxes have greatly reduced traffic volume and city air pollution. It is one of the least polluted city of world today.
Promoting the Public Transport System
The public transport systems (buses / trains / trams) are highly sustainable because they run on much lower ‘environmental cost’, consume much less energy and emit much less pollutants for per passenger transported. But they have to be very ‘competitive’ with private transport and also ‘convenient’ to commuters. There is also need to revive electrically operated ‘trams’ in the busy city areas as it is in Melbourne. At reasonable occupancy rates public transport uses less space and energy than private cars and create much less pollution per person transported.
A large bus occupies approximately 240 square feet of road space and carries 45-50 passengers, while a car occupies 80 sq ft road space and carries maximum of five persons. A bus carrying 45-50 passenger consume only about one-fifth fuel, and produce only a quarter as much pollution and greenhouse gas CO2 per person per kilometer as a private car.
For the same amount of carbon products, buses transport ten times more people than cars can, and the railways trains hundred times more. Buses and trains require far less fuel per passenger for each kilometer of travel. A tram carrying 55 passengers needs about 640 btu of energy per person per km; a city bus with 45-50 passengers would use some 690 btu per passenger per km; while a car with 4 or 5 occupants uses 1,140 btu of energy per person per km. A single occupant car (which is a common practice in most developed world) uses nearly 4,580 btu of energy per km. (Lowe, 1991).
In addition to reducing power consumption and pollution, buses and trains carry more people, more safely and in much shorter time.
Surface rapid rail system can transport 50,000 people per hour and buses 30,000 people per hour, while private cars even with 5 occupants can move only 8 – 9000 people per hour. The underground metros are most efficient and sustainable means of public transport systems in cities. It can transport over 70,000 people per hour and with significantly much less emission. (Lowe,1991).
In many cities light rails or electric trams are now being preferred over rapid rail (metros) systems. Whereas metros requires exclusive lanes, which means building costly and time consuming elevated or underground rail lines and stations, light rails can be build on regular city streets and roads and at much lower cost. British government in the colonial era had planned for such light rail systems in several countries but they have become extinct today. Such projects are now being revived in some 50 cities of world. They are like ‘zero emission’ public transport in busy city areas not affecting the local air quality at all.
The Eco-concept of Car Sharing to Reduce Congestion and Vehicular Pollution
To reduce automobile congestion and pollution in the cities there has to be increase the ‘use of cars’, instead of the ‘numbers of cars’. The idea of car sharing originated in Bremen, Europe in the mid 1970’s after the oil crisis. There are 40 car sharing companies catering 300 European cities with around 38,00 subscribers. This significantly reduces the number of cars on the roads during the ‘peak hours’ and also encourages people to use bicycles as there is less congestion. The concept of car sharing increases the ‘use of cars’ instead of numbers.
Wide Road Network with Bi-Cycle Lanes and Walkways in Cities
The planning for wide road network within the city with bi-cycle lanes, and the volume and movement of traffic also greatly determine the sustainability of a city. Any design feature of roads in cities which allow uniform and smooth traffic flow without congestion, good sight distance, and less interruptions will minimize pollution emissions. And it would be of utmost significance that each city established a relationship between the number of cars allowed to ply and the square meters of roads available for this traffic. Traffic management through measures like segregation of motorized and non-motorized vehicles, encouragement of wider use of bi-cycles through construction of special ‘bike lanes’, and creation of ‘automobile-free zones’ and ‘walkways’ for pedestrians will reduce vehicular pollution significantly.
In Denmark, Netherlands, Germany and other Western European cities, and in Australia, the U.S. and Canada bicycle is fast becoming a popular means of transport with separate bicycle lanes being constructed in the cities. Bike-and-ride facilities are becoming popular in Japan and Western Europe. In Japanese cities, the 1980 census showed that some 7.2 million commuters or say 15 % people rode bicycles to work or to the railway stations. This must have increased substantially by now. In the Netherlands some 30 % work trips and 60 % of school trips are made by bicycle. It also imported tri-ricksaws from India. In the heart of the Amsterdam city only bicycles are allowed to enter. Cuba has declared bicycle as an official means of transport. Nearly all major European cities have developed part of their city centers to people on foot or on bi-cycle. In congested Western Europe, cities like Karlsruhe and Freiburg, Basel and Zurich, Amsterdam and Copenhagen, government is simultaneously promoting public transport and cycling to restrain car traffic, and to promote more compact urban forms.
c). Promoting Urban Forestry (Tree Plantation) : To Improve the Air Quality in Cities
Plants play an important role in mitigation of highly polluted atmosphere and extreme climates in urban and semi-urban areas. Yang et al. (2005) in a study on the role of urban forest and vegetation in air pollution abatement & reduction, found that there was 1262.4 tons of pollutants reduction by the forest cover in Beijing. Planting of trees and shrubs was recommended as a way to combat dust pollution in Russian cities and there was 2-3 times reduction in dust fall by planting a 8 m wide green belt between the roads and buildings.
Vegetation in urban areas help to mitigate air quality problem by reducing the temperature-dependent production of air pollutants, such as ozone (O3), and the VOCs (Volatile Organic Carbons). Tree species strategically planted to shade homes can save 10 to 50 % in cooling expenses. (Taha, 1997). Freer et al. (2004) studied relative pollutant dry deposition velocities and pollutant capture efficiencies of some plant species widely used in Europe urban and sub-urban areas. This included oak (Quercus spp.), alder (Alnus spp.), ash (Fraxinus spp.), sycamore (Acer spp.), Douglas fir (Pseudotsuga spp.), weeping fig (Ficus spp.) and Eucalyptus (Eucalyptus globulus). Species with more complex stem structure and smaller leaves had greater deposition velocities.
Some broad-leaved indoor plants have been identified to remove formaldehyde & other contaminants including the VOCs from the indoor air in cities .They are heart-leaf philodendron (Philodendron scandens), elephant-ear philodendron (Philodendron domesticum), green spider plant (Chlorphytum elatum ), golden pothos (Eppiremnum aureum), peperomia (Peperomia obtusifolia), peace lily (Spathiphyllum clevelandii), snake plant (Sansevieria traifasciata), Chinese evergreen (Aglonema modestum).
d). Promoting Sustainability Education for Urban Dwellers
Sustainable cities will require its residents to live and behave sustainabily. Sustainable living requires judicious and ethical use of water and electricity and all other environmental resources in daily life and also to reduce, reuse and recycle all wastes in daily life. Saving water is also saving energy as huge energy is required to mine and purify water for cultural use and also to treat the wastewater before discharging into the environment. Saving electricity is also ‘reducing pollution and the greenhouse gases’ because electricity is generated mainly by burning fossil fuels.
If a resident can only think of judiciously using the 5 Ps – the potable water, paper, power, petrol, and plastic in daily life, it would greatly lead to sustainability. Simple changes to our daily habits and life-styles can bring significant savings in water and energy in homes and reduction in pollution and greenhouse emissions in cities.
(2). The Technological Measures for Development of Sustainable Cities
Technological measures to construct eco-houses and green buildings for efficient use of natural light, water and energy with integration of the renewable energy sources (solar and wind power), eco-efficient automobiles, recycling of urban waste (solid waste and wastewater) to convert into a ‘resource’ is the key to sustainable urban infrastructure development.
Cities like Freiburg, Berlin and Saarbrucken are known as ‘solar cities’. Freiburg has large number of private and public buildings, facilities and new development projects that run on solar power. The city’s soccer stadium is built from ‘rooftop photovoltaic’. These generate more electricity than the stadium needs, and the extra electricity is fed into the local grid. In the Dutch city Amersfoot, there is a new urban district called Nieuwland. It has been designed to integrate solar energy into the development model.
1). Technologies for Development of Eco-Houses and Green Buildings
The growth in the trend towards construction of ‘eco-houses and green buildings’ has been recognized internationally for development of more sustainable urban infrastructure. Such green buildings would use less natural resources as construction material; be energy efficient, conserve water and electricity, and make more use of natural daylight for interior lighting, and air current for ventilation. Some of the technological measures can be-
a). Use of Environmentally Friendly Construction Materials
A new ‘ferrocement technology’ has emerged which manufacture a highly versatile form of composite building material in which the matrix of cement mortar, brittle by nature is reinforced by a network of steel fibers (mesh) dispersed uniformly throughout the composites. This results in better structural performance of the nearly homogenous materials as compared to that of the individual ones as in reinforced concrete. The technology uses less cement and steel and the calculated energy consumption is much less as compared to conventional brick and cement products. It can be fabricated into almost any shape and is easy to repair. Ferrocement possesses a degree of toughness, ductibility, durability, tensile strength and crack resistance that is considerably greater than that found in other forms of concrete construction. These properties are achieved in structures which are less than 25 mm in thickness, simply unthinkable in other concrete constructions.
b). Sky-light Technology for Efficient Use of Natural Day-lights in Buildings
Researches done on ‘Angular Selective Skylight’s (ASS) by Dr. Ian Edmonds of Daylight Research Group, Queensland University of Technology, in conjunction with Skydome Skylight Systems Ltd. and the Queensland Department of Public Works are using the natural daylight from sun more efficiently for lighting houses and thus reduce dependence on electricity operated lights in big buildings during daytime, and cut upon electricity bills. The best thing is that the sky-light technology provides natural sun light without the radiant heat in summer. In winter, it provides more light and more heat, and in summer less heat and good light. The carefully calculated angle of the laser cut panel allows sufficient light to be reflected down to the shaft into the room’s interior. The natural light is deflected sideways into the room and upwards towards the ceiling. This spreads the light through the room and minimizes glare. (email@example.com)
c). Building Insulation Technology: Improving Energy Efficiency of Homes
Insulation technology using materials which are bad conductor of heat are proving very efficient in construction of energy efficient buildings specially in the cold countries. The level of insulation provided by a product (glass-wool, blanket etc.) is determined from the R-value. The higher the R-value the more effective the product is at reducing heat flow into or out of a home. It is usually recommended to use insulating material of R 2.5 in ceilings and at least R 1.0 in walls. The innovative use of fly-ash masonary block (waste byproduct) and the utilization of foil backed plasterboard in the walls achieved a minimum R-value of 1.0 (as opposed to brick veneer construction which has an R-value of 0.46). The use of ANTICON Blanket of R-value 1.5 under roof sheeting for both insulation as well as a rainwater noise damper, and a sisalation material has proven to a first line of defense against radiated heat in Australian homes. The second line of defense is the use of glasswool with R-value 2.5 (Gold Batts) laid in the ceilings between joists. The colorbond ‘off white’ roof sheeting also helps to emit radiated heat and reflect ultraviolet (UV) light away from the building.
In homes with full insulation the inside ambient average room temperature remains 16-18 o C in high winter when outside average ambient temperature is recorded 4-6 o C between 7 and 9 AM. In the mid of high summer between 3.30 and 5.30 PM when the outside ambient average temperature is recorded 37-42 o C, the inside average ambient temperature in the living area of the house is 35-38 o C, a dramatic reduction in temperature of 2-7 o C.
The Green Roof Concept
Interest in green roof began in Germany and Switzerland in the 1970’s and they are now legal requirements in many areas. The Netherlands, Norway, Denmark, Hungary and several North American and Japanese cities have also followed. In Switzerland, green roofs have been developed to conserve biodiversity. Construction law in a Swiss city Basel require that all new flat-roofed buildings are covered in some form of vegetation. Cities can become ‘refuges’ for rare species endangered by industrial farming in the countryside. Today, green roofs have become a common sight on buildings from private houses to hospitals, factories and office blocks in countries like Germany and Switzerland. (UNEP Report, 2005). The city of Chicago, U.S., has estimates that by reducing the need for air-conditioning they could save US $ 100 million every year.
2). Eco-transport System for Reducing City Air Pollution
It is very important to reduce the dependence of our automobiles on the ‘fossil fuels’ (petrol and diesel) as soon as possible and switch over to cleaner auto-fuel to improve the air quality of cities. A significant reduction in the air borne lead, considerable reduction in the emission of CO, HC and NOx have been achieved by the introduction of LPG (automotive liquid petroleum gas) and CNG (compressed natural gas) and ethanol as auto-fuel. Ethanol is cleaner ‘auto-fuel’ commercialized by Brazil since 1975. It also work as ‘high octane enhancer’ thus eliminating the need of lead or even benzene in petrol. Developing ‘lead free’ petrol and fuel efficient IC engines, introduction of ‘catalytic reactors’ and ‘lean-burn combustion technology’ has also reduced the vehicular pollution significantly. Toyota and Honda has developed low-emission hybrid-car.
a). The Zero emission Hydrogen Power Vehicles
Commercialization of the ‘hydrogen fuel cell’ powered vehicles will provide the answer to the current crisis in the urban environment. Hydrogen is a clean burning substance with much higher calorific value per gram than fossil fuels and the emission product is water vapor. The ‘hydrogen fuel cell’ powered and the solar powered ‘hybrid vehicles’, and those run by rapidly chargeable electric batteries will become non-polluting vehicles for future cities. Automobile industries are testing hydrogen fuelled ‘internal combustion’ and ‘fuel cell’ engines for automobiles and mass transit vehicles.
Hydrogen-powered automobiles are expected to be commercially available soon. By 2010, 50 % of all new buses in the US, shall be powered by hydrogen. Mercedes Benz is bringing out hydrogen fuelled 5th generation ‘eco-car’ called ‘NECAR-5’(New Electric Car) . It can run on methanol converted to hydrogen. Trial run of 5,245 kms from San Francisco to Washington was completed in 16 days, refueling every 480 kms. Daimler-Chrysler is bringing a fuel cell ‘eco-car’ using methanol / ethanol / petrol that can be converted into hydrogen. They are expected to be on road 8 years from now. They will produce very little or no air and noise pollution.
b). Technological Improvement of Zero Emission Pedal Powered Vehicles
There is urgent need to revive the ‘bicycle culture’ all over the world by encouraging and giving incentives to bicycle riders. Appropriate technologies to improve the efficiency and load carrying capacity of present generations of bicycles to enable people to travel even longer distances with loads, a separate bicycle lanes in cities for safe and smooth ride, integrating cycle transport with buses, trams and city trains and with facilities to carry bicycles in them, parking facilities at institutions, work and market places, would encourage bicycle riders to use bicycles more frequently. Some such facilities and incentives have been provided by local councils and government in several cities of developed nations in Europe, Australia, U.S. and Canada. Major technological improvements can be a mono-wheel trailer attached to the bicycles. This would improve the load carrying capacity. Bicycles can also be made two to four seaters with shared pedaling.
A major technological improvement towards higher efficiency in bicycle has been achieved by installation of ‘hub gears’ which allows to increase speed with least efforts. The tires and spoke wheels have also been modified to reduce horizontal air resistance. It is heartening to note that many car manufacturers in the U.S. have switched over to bike production. A quiet revolution is underway to resurrect and reinvigorate human powered forms of transport in industrialized nations.
(3). Converting Urban Waste into Resource and Establishing the Concept of Circular Metabolism for Cities
Natural ecosystems uses a ‘circular metabolism’ where the waste produced by one community is used as a ‘resource’ (food / energy / minerals) by the other. The metabolism of most urban ecosystem (cities) is essentially ‘linear’ with resources (foods) flowing in one direction from the producers in the farms to the consumers in the cities. In the urban ecosystem created by man, nutrients (as food) are taken away from the farm soil, but never returned backed to the soil as it happens in the natural ecosystem where nutrients are recycled back (circular) to the environment through microbial decomposition. The linear system of metabolism is unsustainable as it ends up with waste accumulation, creating the problems of pollution and entropy.
For sustainability, the cities have to maintain an organic link with the farmlands and adopt the system of ‘circular metabolism’ by returning the nutrients obtained as ‘food’, back to the farms as ‘fertilizers’. Much of the ‘city waste’ (at least 80 %) can be converted into ‘compost’ and returned to farms as fertilizers. This would establish and maintain the concept of circular metabolism in cities. Even the municipal wastewaters and the storm water can be treated and recycled back to the residents for non-potable uses like gardening, flushing toilets, washing cars etc. thus significantly reducing the consumption of fresh water.
a). Reuse of Treated Municipal Wastewater and Storm Water in Cities : Promoting the Concept of ‘Dual-Water Supply’ System
The idea of reuse of treated municipal wastewater and storm water is growing all over the world as the shortage of fresh water is being felt increasingly in several cities of world. The concept of ‘dual-water supply’ to the society - pure water only for cultural uses and the treated and recycled wastewater / storm water for all other non-potable uses, are being planned in several cities of world. St. Petersburg in Florida, Rancho Viejo in California, U.S.A, and some cities in The Netherlands has dual-water supply system. Australia has also started this system in some parts of Sydney.
b). Reuse of Urban Stormwater Run-off by Constructed Wetlands in Cities
Attempts are being made in Australia to construct artificial wetlands in the cities and use them for removal of pollutants and nutrients from the urban storm water. Wetlands plants and microbes collectively work to efficiently break down the toxic chemicals in the stormwater/wastewater. This is a low cost, environmentally friendly alternative to conventional wastewater treatment facilities based on the use of chemicals and high input of energy. The treated water is sufficiently clean to be recycled back to the urban residents for non-cultural.
(4). Urban Agriculture : Growing Food Locally Within Cities
A new concept of ‘urban agriculture’ (permaculture) combining food production with architecture has been developed by Australian biologist Bill Mollison (1991). Permaculture is a mini agro-ecosystem to be created within each urban centers and homes to bring the ‘producers’ and the ‘consumers’ of food closer. Food for the city dwellers are procured from farms located far away, with heavy expenditure of energy. Growing some useful food in the cities can also consume all the organic wastes as ‘compost’, thus further helping the urban environment. Hydroponics (soil-less agriculture) are emerging as a simple devices to grow food in cities especially for the production of fruits and vegetables like tomato, lettuce, spinach, strawberries and egg-plants and ornamental flowers like roses, tulip and gladolias etc.
Hydroponics only needs one-tenth of the water needed by the soil crops and can be very successfully practiced in the cities in every house on roof-tops, thereby significantly reducing, not only the cost of transportation of fruits and vegetables from the distant farms, but also reducing the water requirement which is becoming a dearer commodity in the cities.
STATE OF URBANIZATION IN AUSTRALIA
Australia is a highly urbanized nation with about 85 % of its population living in towns and cities which are mostly located in the coastal areas. Australian cities consumed over 1200 square metres of land per person. This also includes the old growth forest lands. Although these settlements occupy less than 1 % of the country’s land area yet they significantly influence the Australian environment especially the terrestrial and the marine ecosystems and their biodiversity. CSIRO has estimated that 60 % of the Queensland’s rare, threatened or endangered plants in the old growth forests lie in the urban growth area of the State’s South-East.
Deteriorating Quality of Air in Australia
Although problems of air pollution in cities is not a cause of concern in Australia, yet with the current rise in numbers of cars it may assume serious proportions in future. Australia being a sunny country the risk of formation of ‘photochemical smog’ in big cities like Sydney and Melbourne cannot be ruled out. Australia’s per capita greenhouse gas (carbon dioxide) emission from the automobiles and other sources, was reported to be highest in world (1996 Report ). Electric water heaters accounts for 62 % of water heating in Australia and produce 85 % greenhouse emissions. 33 % homes use gas water heater and produce only 15 % of emissions. There are only 5 % homes in Australia fitted with solar water heater which has ‘zero emission’.
Air pollution tests carried out by EPA of Western Australia in Perth indicated higher amount of toxic benzene, toluene, ethylbenzene and xylene in the breathing air. Elevated lead levels were found along roads carrying large volume of traffic. Researches indicate that in Australian cities old cars using leaded fuel make 10 % of the total car population, but they contribute to more than half of the total vehicular emissions because of obsolete technology.
Heavy Consumption of Resources and Linear Urban Metabolism
What is other serious cause of concern is that Australian cities consume huge amount of water and have very high rate of linear urban metabolism. They consume huge water and energy resources and also produce proportionally huge waste and pollutants. In 1934, Queenslanders on average used 880 litres of water per 4 person per household, per day. In 2002, the average water use is 1250-1400 litres per 4 person per household per day and is increasing. Some big cities have more than 150 tones of domestic and industrial water consumption per head (1996 Report). All urban centers in Australia with populations of more than 500,000 located near the coast discharge their treated effluent into the seas. Many small coastal settlements discharge untreated sewage directly into the ocean.
Urban Poverty and Increasing Crimes in Australian Cities
Potential ‘ghettos’ are also emerging with pockets of urban poverty. Some inland towns are in sharp decline and new coastal towns appear to be growing at highly unsustainable rate. Anti-social activities, drug abuse, sexual assault and other criminal activities have been on the rise in some Australian cities, especially in Sydney, Melbourne and Brisbane.
STEPS TOWARDS SUSTAINABLE URBAN DEVELOPMENT IN AUSTRALIA
1. Sustainable Housing and Green Building Designs in Australia
Innovations in sustainable building (green buildings) designs and construction has attracted several Australian housing and building industries. The construction of the Olympic Village for the Sydney 2000 Olympics and the integration of sustainable technologies into other commercial and government buildings in Australia such as the ‘Henry Dean Building’ in Sydney, ‘CSIRO Energy Center’ in New Castle, ‘60 L Green Building Project’ in Melbourne, and the government building at 124 Phillip Street in Sydney are good examples of green building concept. The CSIRO building in NSW is a world class energy center to be opened sometimes in 2003. It is an unique combination of energy efficient building design plus small-scale generation units capable of delivering most (90%) of its power needs. This will comprise small wind turbines, building integrated photovoltaic cells, gas fired micro-turbines and provision for hydrogen fuel –cells, all connected to the grid. (www.det.csiro.au/energycenter 2003)
The Queensland Department of Housing has initiated a research project ‘Towards Healthy and Sustainable Housing’. It has designed and constructed a family home at 1 Mary Blow Drive, Rockhampton based on water and energy efficiency, affordability, and safety and security. The Rockhampton Research House Project incorporates contemporary technologies that aim to promote energy and water conservation, increase the use of recycled materials and minimize the use of construction materials that emit potentially harmful gases. In the Research House the external walls are constructed of lightweight masonry blocks made from fly-ash (waste by-product of coal power industry). Another wonderful example of sustainable housing is ‘Harper House’ at Maroochydore, a joint initiative of the Maroochydore Council and Harper’s. The house generates its own solar electricity and purchases energy from the renewable sources when additional power is needed. It collects and uses rainwater, composts all kitchen and green wastes on site and uses energy efficient appliances and water saving devices. The Council has also developed its own water-efficient and energy-efficient sustainable house, the ‘Brahminy House’ at 7 Elsa Wilson Drive, Buderim which do not rely on fossil fuels for its energy demands and is effectively a ‘zero greenhouse gas emission’ building. It has heat pump hot water system and water-saving taps and showerheads.
2. Towards Sustainable Transport System in Australia
CNG operated buses have been introduced on large scales on the roads of Brisbane, Sydney, Adelaide, Melbourne, ACT and Perth. There are now 550,000 LPG & 2086 CNG vehicles running on Australian roads (Report, June 2001). However little impact have been made on the vehicle size and efficiency. With petrol still cheaper much change is unlikely to be made by the current approach.
However, Australia’s use of public transport is much lower than other developed nations and public patronage has declined significantly in the last 50 years. This is mainly due to high cost of traveling.
Australian cities are promoting ‘bicycle’ transport significantly by constructing separate bicycle lanes, parking facilities, and facility to carry bicycles on buses and ferry. In 2005, bicycle sales in Australia topped 1.1 million. This was 13 % ahead of car sales (988,269). (www.cyclingpromotion.com). (BCC Report, 2006).
Large freeway programs are being undertaken in many of our major cities, although this is contrary to the transport planning and National Strategy for Sustainable Development.
Control of Automobile Pollution in Australian Cities
The Australian Design Rules (ADR 37) came into effect in 1986 which forced all the car manufacturing companies in Australia to install ‘catalytic converters’ in cars manufactured from 1987 onwards. However reduction in CO levels because of ADR 37 has outweighed the effect of an increase in overall vehicle numbers. Toyota Australia has announced that its ‘Hybrid Car’ named ‘Primus’ will produce emissions up to 80 % less than the maximum levels set by ADR.
3. Towards Sustainable Waste Management in Australian Cities
Australia has taken some excellent step towards management of municipal solid wastes and the various city councils in the metropolis are primarily responsible for waste collection and management. (More has been discussed in topic on ‘Waste Management’)
BRISBANE CITY : STEPS TOWARDS SUSTAINABILITY
Brisbane is the fastest growing city in Australia due its excellent climatic conditions. By 2016, the population of Brisbane is predicated to be more than 2 million, with 110,000 more cars traveling on the road and drivers are expected to make 5.1 million car trips each day (up from 3.9 million in 2001). Recent research has shown that about 50 % of car journey in Brisbane are for less than 5 kms. Approximately 30 % of trips are for less than 3 kms and 10 % are less than 1 km – an easy distance to walk. (BCC Report, 2006). Currently cars emits 70 % of the smog-forming pollutants which will increase substantially by 2016. Traffic congestion already costs Brisbane $ 2.5 billion per year.
More than 630 million liters of water is used in Brisbane city every day with the average Queensland household using about 340 kiloliters of water each year. According to BCC at this rate, it is estimated that the current supply will meet demand only up to 2023. (BCC Report, 2002).
The Brisbane City Council (BCC) has issued a plan called ‘Living in Brisbane 2010’ to achieve the vision of ‘clean and green’ city by 2010. Easing traffic congestion, reducing vehicular pollution, allowing free and fast flow of public transport, conserving water and electricity, protecting the old growth forests, are some important objectives. BCC held the ‘Asia Pacific Cities Summit’ in 1996 and again in 2003.
1). Sustainable Transport System in Brisbane
Planning for sustainable transport system in Brisbane promotes growth around major centers so that people do not have to travel far for what they need. The centers are being efficiently linked with residents, each other and the CBD by public transport, so that people can easily connect to essential services like schools, workplaces, hospitals, shopping towns and recreation centers. A new local legislation ‘banning truck parking’ in residential streets is addressing safety, noise and amenity concerns. A 50 km per hour speed limit in local streets is improving safety while reducing noise pollution for residents. BCC has purchased 80 low-floor, easy access, air-conditioned low-emission gas powered buses. Transport Plan for Brisbane aims for-
Council has already constructed more than 500 km of on-and off-road bikeways and 10,700 km of walking paths and is set to trial bike racks on Council buses. There is plan to construct an extra 295 km of off-road walking and cycling paths and 905 km of on-road bikeways, plus a ‘free city bike scheme’. The Plan also encourages better facilities like cycle lockers, free bikes for use in the inner city area, bike parking and drinking water fountains.
2). Sustainable Homes and Housing Development in Brisbane
BCC and State Government is encouraging residents to install ‘rainwater tanks’, ‘solar water heater’ and PV Systems in houses and is giving substantial rebate on them. By using 3000 liters rainwater tanks for toilet flushing, gardening and hot water system, average Brisbane resident would be able to reduce their annual use of municipal water supply by 40 % or 70,000 liters every year. Residents with PV System can sell electricity to ENERGEX during the day-time and buy it back during the night-time at a cheaper rate. ENERGEX in Brisbane buys an amount of renewable energy equal to their energy use.
BCC has introduced a new ‘Natural Asset Local Law’ which will expand the area of protected vegetation across the city by 60 % - from 17,000 ha to 50,000 ha of both public and private land. It largely focuses on protecting the old growth forests, bushland, waterways and trees in Brisbane’s newly developed suburbs and outer suburbs. BCC has also issued new guidelines to prevent the proliferation of large houses built on traditional 16 perch (404 sqm) lands and reduce the height, length and width of houses on small blocks (under 450 sqm) for better ventilation and sunlight.
The new and innovative ‘sky-light technology’ to use natural daylight efficiently and reduce electricity bills are being experimented in Brisbane. Pyramid style sky-lights were installed in a classroom at Waterford State School. The natural light levels reached 400 lux without artificial lights, as compared to just 50 lux in the controlled classroom under same conditions. The heat input during bright conditions was about the same as for fluorescent lighting. In terms of annual reduction in greenhouse gas CO2 emission by not using electricity for lighting, the energy audit revealed that a 20 classroom school fitted with skylights reduced about 40 tons of CO2 every year. The Herbarium at the Brisbane Mt Cooth-ha Botanical gardens has also installed an inverted pyramid skylight. The light levels in the building is excellent for plant requirements, while reducing the heat from the sub-tropical sun at high altitudes (firstname.lastname@example.org).
The future of humanity will be shaped largely by conditions in the cities. The quality of life for generations to come will depend on whether or not governments find ways of coping with accelerated urban growth and whether or not local authorities succeed in combating urban pollution, limiting the numbers of automobiles, safely disposing all municipal wastes, curbing the proliferation of urban slums, and securing good health and sanitations for city dwellers. Technocrats will definitely deliver the promised ‘zero emission’ eco-vehicles, within a foreseeable future, but whether the local councils can provide roads and infrastructure to cope with the increasing population of automobiles is a question because the non-polluting and zero emission vehicles on road cannot rule out congestion; eco-builders will provide all necessary infrastructures for a sustainable eco-homes, but whether the residents will become environmentally educated and conscious to use them despite their high initial cost (although they have lower environmental cost and pay-back is within a reasonable time) is a question; technocrats will provide solutions to reduce and also reuse and recycle all wastes generated by the society, but whether the society will cooperate with equal enthusiasm and responsibility, is a question. A number of environmentally friendly instruments / appliances have to be made ‘mandatory’ for fitting and use in modern homes through appropriate legislation.
If cities are to continue to be the engines for the economic growth of nations, as they have been throughout the human history, their future growth have to be on the principles of environmentally sustainable development. The fate of cities will determine not only the fate of nations, but also the fate of the planet earth. We ignore the fate of our cities at our own peril and at the cost of our own future.
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Frey, Hildebrand (2002): Designing the City : Towards a More Sustainable Urban Form; MacMillan Academics;
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Some Useful Websites
(1). For Energy Efficiency in Homes : www.env.qld.au ; www.seda.nsw.gov.au;
(2). For Saving Water in Homes : www.savewater.com.au ;
(3). Sustainable Urban Environment : www.urbanecology.org.au;
(4). 60 L Green Office Building in Melbourne (www.60lgreenbuilding.com)
(5). CSIRO Energy Center in New Castle, NSW ( www.det.csiro.au/energycentre)