Every day, another 200,000 people move into the world's cities and towns. This rural exodus of almost biblical proportions means that a city the size of Chile's Santiago or the Democratic Republic of Congo's Kinshasa is being formed every month.
Urban sprawl is so commonplace that Cairo and Alexandria, which lie 200km apart, could merge in the foreseeable future. This is the stuff of nightmares for Egypt's urban planners. Elsewhere, urbanisation is leading to the growth of monster cities. Mexico City has encroached on two adjacent states and the Argentinian capital Buenos Aires covers 30 different municipalities.
Thanks to permissive land-use planning and growing affluence, sprawl is increasing at twice the rate of urban population growth in the USA. Las Vegas is the fastest growing metropolitan area. Canada has three of the world's ten urban areas with the most extensive sprawl - Calgary, Toronto and Vancouver.
Last year, for the first time, more than half of the world's population lived in towns and cities. This is expected to rise to 67 per cent, or about five billion people, by 2030. More than 90 per cent of this increase will occur in developing countries. This implies a plague of problems for the planet's population. As a result, inequalities and social divisions are widening.
Slums are mushrooming as displaced people move into cities. Competition is increasing for land, water, shelter, jobs and food. This is turning into a fight for survival. About one billion slum dwellers have yet to be integrated into urban plans for housing and basic infrastructure and services. This is expected to rise by 2030 to more than three billion people, which is about 40 per cent of the world's population.
Now UN-Habitat has issued a stark warning that such rapid urbanisation could lead to large-scale violence as social tensions rise between migrants and host populations. This in turn will lead to ever more ungovernable cities. According to the agency, urban planning is the only thing that can save the planet from this maelstrom - but not urban planning as we know it.
"There is now a realisation that in many parts of the world urban planning systems have changed little and are often contributors to problems rather than tools for human and environmental improvement," maintains UN-Habitat executive director Anna Tibaijuka. "In most parts of the world, approaches to planning must change. A new role in sustainable urban development has to be found."
The provision of housing and basic services is one particular problem for developing nations. Youth unemployment is another. This places demands on education and training facilities as well as investment in sports and recreational facilities. In Asia and Africa, urban planning must balance rapid urbanisation, poverty, informality, slums and access to basic services.
By contrast, in developed countries and former communist nations making the transition to market economies, the planning challenges come from urban shrinkage. Here planners are struggling with meeting the cost of underused infrastructure, finding alternative uses for abandoned social facilities and working out what to do with huge swathes of empty homes and commercial and industrial sites. Rapidly ageing populations are putting added pressure on health care, transport and other amenities.
All across the world, a significant dilemma confronting planners and politicians is how to balance the natural and built environments. Here UN-Habitat stresses the importance of tackling climate change through urban design, improved building materials, power and water distribution systems, sustainable transport and photosynthetic public spaces. The aim must be to develop carbon-neutral, eco-efficient cities without slums.
UN-Habitat acknowledges that no single urban planning model can be applied worldwide. It recognises that planning systems must be shaped by and respond to their local contexts. Although older forms of urban planning such as masterplans have been discredited, strategic spatial and public-friendly planning are seen as viable options.
Countries must develop a national perspective on their urban areas, with governments taking a more central role in leading development initiatives and using urban planning to ensure that basic needs are met. At a lower level, civic or local authorities must provide the leadership to design and implement urban plans, placing particular emphasis on ensuring that communities take part in the process. Cities should set out a development strategy that covers all sectors and political representatives.
By 2025, 1.2 billion people will be living in the Commonwealth's urban areas compared with 750 million today. Thirty-two of the 76 "million-plus cities" are expected to more than double in size between 2000 and 2025. It is predicted that Abuja, Dar es Salaam, Kampala, Klang, Mombasa and Nairobi will grow by more than 160 per cent.
In India, the Commonwealth's most populous country, the level of urbanisation remains low, at about 30 per cent. But this proportion is expected to increase to over 55 per cent in the next 40 years. Urban growth rates of four per cent a year, as found in Gambia, Kenya and the Solomon Islands, represent an almost doubling in urban numbers by 2025.
Commonwealth Association of Planners secretary general Cliff Hague finds that UN-Habitat's message carries a particular resonance with his members. "We have had 'anti-urban' policies such as attempts to contain urban growth and resist development. They fail business and they fail the urban poor. We have also had 'non-plan' policies with utopian dreams of privatisation and unregulated market forces. These paved the way for the global financial crisis," he says.
"It is time that we adopted evidence-based pro-urban planning policies that identify economic opportunities and unlock the potential of land but also recognise the need for equity and carbon emissions management," he explains. "There is still time to make a difference. But each year that slips by makes it harder to rectify the diseconomies of urban growth such as traffic congestion, car-dependent sprawl or slums lacking basic services. Preventative urban medicine is needed. Strategic urban planning is essential."
Global Report on Human Settlements 2009 is available at PlanningResource.co.uk/doc
THE URBAN CHALLENGE
- About 1.6 billion people live in slums.
- There are at least 40 mega-cities with populations of ten million or higher.
- Eight out of ten of the world's most populous cities stand on earthquake fault lines.
- Seventeen per cent of developing world cities grow by four per cent or more annually.
- A total of 3,351 cities are in low-lying coastal zones that are at risk from climate change.
- Sixty-eight per cent of sub-Saharan Africa's urban areas are located in coastal zones.
- Five out of eight city dwellers in sub-Saharan Africa live in slums.
- Fifty-two per cent of the world's 3.3 billion urban residents live in cities and towns of fewer than 500,000 people.
PLANNING SKILLS CRISIS
Much has been made about the skills gaps afflicting UK planning over the past decade. Yet the country has a great deal to offer. According to the Commonwealth Association of Planners (CAP), few of its member states have enough planners with the right skills to make the difference UN-Habitat wants to see.
At one end of the scale, mega-cities are developing without up-to-date plans to steer growth in sustainable directions. On the other, small island states are vulnerable to climate shocks. CAP points to the Maldives, where only a handful of professional planners are in place.
More than half of the world's countries have no planning schools. Of the 550 universities that offer planning degrees worldwide, 320 are located in just ten nations. The remaining schools lie in 72 different countries. Only a quarter of developing nations have planning educational facilities. UN-Habitat argues that this dearth is a compelling problem. Just 342 institutions are members of a planning school association or network, leaving 208 schools that do not benefit from the input and quality control offered by an accreditation system.
UN-Habitat argues that a major challenge is the need for planning objectives and tools to be understood by architects, engineers, lawyers, administrators and the elected officials who must endorse planning interventions and support plans. University incentives in many countries do not support the education of non-degree students.