There is a growing perception that life in the world’s cities is growing steadily and inexorably worse. Disciples of this view hold that decisive action must be taken now to slow this decline and that only a radical change of lifestyle for all of us could ever hope to reverse it. If this is so, then it is a fundamental problem for us all. In the developed world, the huge majority of people live in an urban environment. In the developing world, the proportion of urban dwellers is smaller but still growing at an exponential rate as a result of population growth and migration towards the cities.

In Northern Europe, people spend over 90% of their time inside and in the winter months, this can rise to almost 100%. If they are not inside, people are usually travelling from one building to another, using civil infrastructure facilities such as roads, bridges and railways. This should not be terribly surprising: apart from a few months (or sometimes days) in the summer, much of the temperate zone could not support human life were it not for the technology we have developed which allows us to survive in this hostile environment. For most people in the developed world, most of the time, the urban environment is their environment. In everyday experience, the wider environment of trees, rivers and the rest of the biosphere has little impact on city dwellers. Environmentalists are therefore usually portrayed as somewhat unbalanced, giving too much importance to nebulous ideals and trying to spoil everyone else’s fun.

The quality of the urban environment obviously has a direct effect on the inhabitants of cities and towns but its also has an effect on the people and environment outside the city limits. Construction of buildings and infrastructure require vast quantities of raw materials, the energy requirements of an urban lifestyle require the extraction and consumption of precious non-renewable resources and the enormous amount of waste generated has to be dealt with out of town.

City life provides a large number of people with all their physical requirements, while isolating them from the consequences of their behaviour. Nothing turns people into vegetarians quite like a visit to an abattoir, and this principle applies equally to degradation of the environment. Take for example the fate of food packaging. At no point in the supply chain from production to disposal does anyone take any responsibility for the effect of their activities. There is no immediate reason why they should, as these effects take place somewhere else. They are, in economic terms, external costs and as such have no effect on profit, which is the reason for the existence of the supply chain. There is therefore no pressure for change.

This same principle holds true for many aspects of the urban environment. Buildings, for example, are made by one party, sold to another and demolished by a third. The economic structure of the situation encourages each party to act for immediate, short-term gain. Any consideration of longer-term consequences would cost money for the individual concerned. However, avoiding such consideration has wider costs for us all.

The infrastructure required to support the urban environment includes communications links, supplies of power, food and water, sewage and waste processing systems and a myriad of lesser support functions, all vital to the continued functioning of the city. Each of these has, to a greater or lesser extent, a detrimental impact on the quality of the wider environment and, in some cases, that of the urban environment too. Reservoirs drown valleys and sewage sludge contaminates the seas and fields, landfill sites stink and pollute groundwater with toxic leachate. Roads are required to bring food and other goods into the cities but the traffic reduces air quality, leading to health effects and a reduced quality of life.

The physical structure of a city causes detrimental environmental effects in a variety of ways. The materials used to make buildings must be extracted and processed, then transported to the city. Covering vast areas with impermeable tarmac and concrete causes storm runoff which flushes surface pollutants and untreated waste into rivers and the sea. Careless design of buildings unnecessarily wastes energy and water and reduces the quality of life of the inhabitants through higher bills, poor indoor environment and lack of facilities. But how did this situation come to be?

There is a common underlying presumption among environmental commentators that urbanisation and the industrial society are the worst things that have ever happened to the world. There is often an implication that we should be making every effort to return to an idyllic pastoral lifestyle which was supposed to have existed at some undefined point in history prior to the industrial revolution. However, there are a number of problems with this way of thinking. Firstly, although environmental degradation was undoubtedly less severe during this golden age, so was the size of the population, life expectancy and standard of living. Biodiversity was greater but so was infant mortality, poverty, disease and hunger.

Environmental degradation, like the human population that causes it, did not spontaneously begin at some point in recent history. For the developed countries of northern Europe and Asia, a convenient starting point for the history of our environment would be the end of the last ice age, around 10,000 years ago. For many millions of years before this the area was buried under kilometres of ice. With the retreat of the ice sheet, the area was colonised by hardy plants and arctic animal species and as the climate continued to improve, biodiversity increased as a wider variety of organisms was able to thrive. Humans moved into the area as it developed the capacity to support them and within two or three millennia had established fixed settlements. At around this point, large areas of forests began to be cleared and species started to be extinguished. This process has been continuing ever since.

The industrial revolution did undoubtedly have a dramatic accelerating effect on this process, coupled with the beginning of reliable measurements and records. However, the process has been inextricably linked with human development in general; as population increases, so does pollution. The fact that quality of life has also increased at a comparable rate is often overlooked.

The UK Government has recently taken the first steps toward defining quality of life indicators, which include social, economic and environmental issues in an attempt to give an overall indication of progress toward (or away from) sustainable development. In the supposed "golden age", environmental measures would have been well represented but performance to economic and social indicators would have been extremely poor. Today that situation is reversed but the overall effect is still an improvement. This is particularly so if you consider per capita impact: the population of Europe in 1994 was around 509 million, a 30% increase since 1950; and this is among the lowest rates of increase in the world.

At the moment, the per capita impact on the environment of an urban lifestyle is around ten times that of a more dispersed, rural lifestyle. However, it is hard to imagine the current population of the developed world dispersed throughout the countryside, living a supposed low-impact life. Firstly, we would not know how and secondly, there isn’t enough room. It appears more likely that the only way to support the existing population is to continue development of the urban model to let each area do what it does best: live in the towns and use the countryside to support the towns with food, water and other requirements.

The answer to the problems of the Urban Environment is not to turn the clock back but to keep going forward. But surely if we are to do this, today’s problems will only get worse. What about the traffic gridlock? What about air quality? And waste, sewage, resource depletion, etc. etc. etc.? Surely if we keep going on our present course we are headed for disaster.

This would be fair comment if we continue to make decisions today using the knowledge and experience of 50 years ago (as has happened in some cases, such as the roads programme) but today we are aware of the problems that have been caused by past mistakes and we can learn from them. For each of the problems identified above there is a sustainable solution. In many cases there is considerable inertia slowing movement from the old methods to the new but we do have the answers now and we are capable of solving the problems we face. The now famous new Report to the Club of Rome, Factor Four, sets out in simple detail how it is possible, with existing technology, to reduce energy consumption by 75% or more. In the context of the environmental damage caused by energy consumption in the developed world, it seems incredible that we have not already embraced this approach. There is no need to build further power stations, no need for dirty technologies like coal and nuclear power at all. It is only the combination of a lack of awareness and a flawed economic system that allows this absurd situation to continue.

Every one of us is paying at least four times as much as we should to heat our homes, travel to work and do all the other energy-intensive things we like to do. And of course, these costs are passed on to us in everything we buy which also has to be processed and transported. As Jonathon Porritt writes in his review, "This book should make you spit with rage – at the mainstream engineers, scientists, economists and politicians who will stand between us and a genuinely sustainable future for all the Earth’s people. As Factor Four so cogently demonstrates, most of the technological solutions to our problems are there for the taking right now. If only…"

The urban environment can be viewed on several different levels, from the basic infrastructure up to the overall effects of urban living. Many aspects of city life generate direct impacts on the wider environment and on the inhabitants of the cities. However, many of the major concerns, such as air quality and traffic congestion arise from the complex interaction of a multitude of simple factors. The study of complexity and emergent behaviour is a relatively young discipline, which is reflected in the limited success we have enjoyed so far in addressing these problems.

Complex systems like cities have so many interacting influences that the application of any measure intended to modify one aspect will have secondary effects throughout the system. For example, the introduction of Greenways (dedicated bus lanes) in Edinburgh has succeeded in increasing the speed and popularity of bus journeys through the city. It has also altered the dynamics of traffic flow and parking through the city to the extent that shopkeepers in some areas claim they are being forced out of business. This was not the intention of the measure but it still falls to the politicians charged with running the city to decide whether the overall outcome is to the greater good.

Many of these effects are so intertwined and act on each other in such unexpected ways that it is often difficult to prise them apart so that they can be addressed individually. The complexity of the situation can make tackling the problems seem a daunting, even impossible task. However, there is already a small but growing movement which aims to improve every aspect of urban life, in terms of its effects on both consumers and producers, city dwellers and the environment. Whichever aspect of the current situation you choose, you will find a group of self-motivated individuals trying to improve it.

Take some of the examples used so far. Water supply is a problem for many cities but we already have low flush WC facilities, even composting toilets which require no water. Sewage treatment similarly displays all the signs of a problem solved by Victorian engineering, which is now too big for that solution. But if you follow up the "supply chain" of sewage, you find the European Parliament setting minimum environmental standards, which are imposed on the Environment Agencies, which enforce them on the water authorities. This problem is not getting worse, despite growth in the number of "suppliers".

Road transport has a reputation for causing air pollution, congestion and not a little frustration, while reducing the quality of life of all concerned. But is this assessment reasonable? As a working generalisation, people live out of town because they choose to (often because of the air pollution caused by cars). If they could not do this, they would either have to live in town (reducing their perceived quality of life) or work outside town (reducing their income). Presumably most commuters who have thought about it consider that the price they pay to commute, in terms of reduced free time, health, quality of life and so forth, are outweighed by the increase in job satisfaction, income and other factors. The exponential increase in the growth of commuter traffic that has taken place over the past few decades would seem to lend weight to this interpretation.

However, with each additional car on the road during the rush hour, the price increases but the rewards do not. Thus, the plight of commuters grows ever worse and the situation begins to climb the political agenda. Commuter traffic has come to represent the worst aspects of city life. It is often portrayed in the press as an insoluble problem, set to grow ever worse. This is simply unreasonable: there are a number of solutions, with a wide range of political palatability, such as road pricing, parking charges, investment in public transport and even tele-working. As the situation worsens, the most acceptable solutions will appear preferable and be adopted.

Similarly, when building the structures that form our cities, circumstances encourage behaviour that maximises short-term gain at the expense of long-term prosperity. The current economic climate encourages builders to complete each development as cheaply as possible. There are certain rules and standards which must be observed but to win a contract and then complete it profitably, the only other considerations are economic. This is not an unreasonable situation: we all have to eat and the market economy appears to be the least bad way of fulfilling this need. However, the situation is causing considerable problems for the wider environment; so much so that it is beginning to threaten our quality of life. It is time to sit up and take notice.

The solution to this problem, as to the other examples, lies in a combination of education and economics. We have developed the urban environment and improved the standard of living in the developed world at the expense of the wider environment. However, we are now starting to realise that this cannot go on. Having already opened our eyes to the problem, we need to establish what can be done about it. For each of the examples above and for many others, there are already solutions. What is required now is the will to implement them.

To a large extent, these solutions will be implemented when the costs become so great that the sustainable solution becomes the cheapest solution. But this requires that the full costs of all our actions are reflected in the simple, financial price we pay. This is where the economic part of the solution comes in. Schemes have already been suggested for road pricing and parking charges in major cities. These are a first attempt to incorporate some of the additional costs of commuting into the price paid by the commuter. These costs include a reduction in air quality, health effects, danger and reduced quality of life for city dwellers. The small charges proposed are unlikely to come close to accounting for these costs but they are a step in the right direction. Most importantly, once this precedent has been set and people become used to paying for environmental benefits, it will be an easier matter to increase the price so that they are paying the real cost.

Market economics has proved itself in recent times to be the most effective and efficient form of government. In terms of sustainability, the only fault in the system is that incomplete information is fed into it, so that inappropriate actions result. If we are to sustain our developed way of life, we must learn to identify the full costs of our actions and begin to take appropriate steps to incorporate them into the existing economic system. The longer we delay this course of action, the larger our overdraft becomes and the more we will have to repay in the end. However, the first signs are already appearing to indicate that we are waking up to the reality of our predicament.

The Factor Four (and Factor Ten) movements show that we already have the capability to maintain our quality of life using a sustainable level of resources. What is now required is not a radical change of lifestyle but a gradual acceptance that we know how to live sustainably and the sooner we begin to move in this direction, the easier it will be. Besides, full cost accounting still includes the original economic factors, so any move toward sustainability will, by definition, also be an increase in prosperity. Saving the world is not just the right thing to do, it’s the selfish thing to do.