Ours is an urban world. In Brazil, for instance, where 88% of the population lives in metropolitan areas. Or in Switzerland, where nearly 85% live in major cities. Or in China, a country where more than 60% live in conurbations today; 40 years ago, it was less than 20%. This list could be expanded to encompass almost the entire planet; overall, the number of urban dwellers has risen dramatically.

However, two striking features emerge from observations of Africa. Firstly, the percentage of rural population is still relatively high. In Ethiopia, for example, a scant 17% live in urban agglomerations, while in Nigeria that segment has just surpassed 50%. These figures are important because Nigeria and Ethiopia, with their respective inhabitant counts of some 200 and 100 million, are the most populous countries on the continent. And secondly, the growth of the planet's population is occurring primarily in cities – as a consequence of rising birthrates, migration and rural exodus, and the consolidation of villages and towns into major cities. In highly urbanized regions such as Switzerland and Brazil, the cities are growing at a rate of 0.5 to 1% a year. In many African countries south of the Sahara, the increases are between 3% and 7%. These seemingly small yet, in their impact, gigantic numbers determine the speed with which new cities spring up – planned, unplanned, and semi-planned. In all these cities, people need to be able to live: they need a social and climate-compatible infrastructure to live and work. This, along with the pace of change, is the challenge awaiting urban planners and developers over the years ahead.

Three potential solutions
Obviously, there is no single solution for these worldwide problems. There are, however, three global strategies that are fostering progress at a local level. First of all, the further advancement of existing structures; secondly, so-called "leapfrogging" in which multiple developmental stages are skipped in order to trial more sustainable models; and lastly, strategic city planning in lieu of traditional master plans.

Transformation and change
In many areas the main thrust is on working with what already exists rather than creating new cities, buildings and infrastructures. This applies to the Americas and equally to parts of Europe. In lots of cities in the former, the goal is to remedy the social injustices manifested in unequal access to resources etc. In many of them – as exemplified by São Paulo and Los Angeles – the low-income demographics tend to be the users of public transportation. However, these transit systems tend to serve inner-city areas – and are sparse and inadequate in the populous residential suburbs. High-income segments are wont to travel in their own cars, which pollute the air and consume a disproportionate amount of space. There are long-standing, serious initiatives aimed at correcting this imbalance. In Curitiba (Brazil), for instance, then-mayor Jaime Lerner integrated permanent express bus lanes into the existing road network, resulting in greater social justice: access to affordable mobility and hence to education and the arts. The project also creates jobs, because almost anyone can become a bus driver. In the area of low-income housing, France can boast several remarkable projects. Take the deeply engaged, prize-winning architectural firm of Anne Lacaton and Jean-Philippe Vassal, which succeeded in transforming a series of overcrowded, socially problematic high-rises into attractive residential properties. They did so without new construction and without relocating the residents: the small apartments were expanded outwards by adding an additional, flexible-use layer of space.

Leapfrogging
Perhaps the most exciting approach, leapfrogging is most relevant in the southern hemisphere, e.g. in Sub-Saharan Africa, India and Southeast Asia. From a European perspective, many of these regions, cities and societies are viewed as backward and in need of development. Often enough, though, the opposite is the case. In Sub-Saharan Africa and Southeast Asia slum dwellings are often located on bodies of water – where their inhabitants have evolved pioneering construction methods and lifestyles that can be a blueprint for cities built at sea level. Naturally these types of construction cannot simply be replicated, but they can serve as models for fresh concepts and strategies in urban planning. This also applies to the development of new infrastructure solutions that don't have to be expensive, centrally managed and all-encompassing to produce the desired improvements to people’s lives. In Ethiopia, some 80% of the population uses the most sustainable and healthy means of transportation there is: walking. In doing so, they have already realized the urban planners’ dream of a pedestrian-friendly city. The country’s emerging cities, now at a very early stage in their evolution, have the unique opportunity to leapfrog American and European blueprints – which are designed for cars – and land directly in a more sustainable future.

Departure from traditional master plans
The third route is strategic urban planning. This entails transforming or rebuilding a strategically relevant area in such a way as to reshape the urban character as a whole – the result of intervening in exactly the right location. This in turn spawns a new urban logic. The Highline in New York is a prime example. Here an elevated city park was created along a decommissioned monorail track that is flanked by former abbattoirs. It has made an entire district accessible as a space for recreation and interaction – but, in one sense, almost achieved the opposite. The park has made this district so attractive that it has become prohibitively expensive for most home-buyers. Another example is the extension of China's high-speed rail network. It connects the interior of the country with the coast – i.e. a series of major cities – in a way that makes air travel less appealing and necessary, and hence diversifies urban growth into multiple centers. This discourages the emergence of those much larger and ultimately less efficient cities that suffer from traffic jams, air pollution and peripheral residential ghettos. Instead it promotes polycentric, well-connected urban regions with smaller ecological footprints.

This is one the most crucial challenges we face both today and tomorrow: enabling a society that is highly networked both regionally and globally while – promoting pedestrian-friendly cities at the local level. In other words, restoring the quality of life and time, while simultaneously reducing traffic and emissions.


Fabienne Hoelzel is professor of design and urban planning at the State Academy of Fine Arts Stuttgart and founder/director of FABULOUS URBAN.