According to a UN Habitat forecast, two thirds of the world's population will live in cities by 2030. Not least because of their population density, cities have become a huge focal point when it comes to sustainable development.

Autor*in Anna Rees, 07.15.14

In 2000, 47 percent, or almost half, of all people were living in a city. By 2008, more people were living in urban environements than in rural settings (3.3 billion). This development is leading to so-called Megacities. These are not the only sign of increased urbanisation with the number of small and medium-sized cities also growing steadily.

What is a Megacity?

A megacity is pegged as any city with more than 10 million residents. Another term often used to describe this is cornubation, a somewhat more comprehensive label that incorporates agglomeration areas such as the Rhine-Ruhr region in Germany’s west which has 11.9 million inhabitants (2010).

Of the 30 biggest megacities worldwide, 20 of them are in Asia and South America alone, including Baghdad, Bangkok, Buenos Aires, Delhi, Dhaka, Istanbul, Jakarta, Karachi, Kolkata, Manila, Mexico City, Mumbai, Osaka-Kobe-Kyoto, Rip de Janeiro, Sao Paulo, Seoul, Shanghai, Teheran and Tokyo-Yokohama. European megacities include London and Paris and the UN estimates that the number of megacities worldwide will only increase.

The explosive growth of these and other cities is a rather new phenomenon, a result of industrialisation. The megacities of the world differ not only according to whether they lie in the southern or northern hemisphere, but also by country, climatic and political conditions. Megacities can be rich, poor, organised or chaotic. Paris and London are megacities but it’s difficult to compare them demographically or economically with Jakarta or Lagos. Rich megacities tend to stretch out further than their poorer counterparts: Los Angeles’ settlement area is four times as big as Mumbai’s despite its population being smaller. Rich city inhabitants have a much higher rate of land consumption for apartments, transport, business and industry. The situation is similar in terms of water and energy consumption, which is much higher in affluent cities. Cairo and Dhaka are without doubt ‘monster cities’ in terms of their population size, spatial and urban planning. But they are also “resourceful cities,” home to millions of people with few resources.

Megacities and Supply Shortages

The high population levels in megacities and mega urban spaces are leading to a host of problems such as guaranteeing all residents a supply of basic foods, drinking water and electricity. Related to this are concerns about sanitaion and disposal of sewage and waste. There isn’t enough living space for incoming residents, leading to an increase in informal settlements and slums. Many urban residents get around via bus, truck or motorised bicycles, leading to chaos on the streets and CO2 emissions leaking into the air.

The faster a city develops, the more critical these issues become. Due to their rapid growth, megacities in developing countries and in the southern hemisphere have to battle in order to provide for their inhabitants. Between 1950 and 2000, cities in the north have grown an average of 2.4 times. In the south they’ve grown more than 7 fold over the same period. (Bronger 2004). Lack of financial resources and sparse coordination between stakeholders at different levels intensify the problems. Megacities usually do not represent one political-administrative unit, instead dividing the city into parts such as with Mexico City, which is made up of one primary core district (Distrito Federal) and more than 20 outlying municipalities (municípios conurbados) where differing planning, construction, tax and environmental laws are carried out than in the core district.

Two key causes behind city growth are high rates of immigration as well as growing birth numbers. People move to the city with the hope of a more prosperous life and leave the country in search of brighter prospects. Without careful planning and infrastructure in place, this road can often lead to another poverty trap.

As Cities Grow, So Too the Slums

As cities grow, so too do the unplanned and underserved areas, the so-called slums. In some regions of the world, more than 50 percent of urban populations live in slums. In parts of Africa south of the Sahara, that number jumps to around 70 percent. In 2007, a reported one billion people lived in slums and by 2020, that figure could grow to 1.4 billion, according to the UN.

What are slums? The UN defines them as overcrowded, poor, informal forms of housing that lack reasonable access to clean drinking water and sanitary facilities and deprive residents of power of the land.

Above all, slums are a structural and spatial expression of lack of housing and growing urban poverty. The well-known symbols of this are makeshift huts, such as the favelas in Brazil, but also desolate and overcrowded apartment buildings in major Chinese cities where the growing army of migrant workers and workers find makeshift accommodation.

The reasons so many of these cities are poor include underemployment and insufficient pay as well as low productivity within the informal sector. Around half the people in megacities that lie in the southern hemisphere are employed in the informal sector, many of whom are coerced into accepting any kind of employment. They sell various products – cigarettes, drinks, food, bits and pieces – simple services like shoe cleaning and letter writing as well as smuggling goods or ending up in prositution. Exploitation is at times rife in slum settings due to insecure residences, lack of legal protection, poor sanitation and unstable acquisition conditions.

Come In If You’re Rich – Gated Communities

Parallel to the growth of slums, gated communities – or exclusive neighbourhoods – are also on the rise. These are fenced and well-monitored communities in which affluent members live, further driving the trend towards separation among urban populations.

But it’s not just living spaces splitting the cities – globally, there is a major push towards big new building projects like über-modern banks and business districts which stand in stark contrast to informal areas for the poor. These central business districts (CBD) are often siloed off from the main part of the city and migrate, along with the gated communities, towards the outskirts of town as is the case in Pudong, Shanghai and Beijing.

For the most part, urban planning is based on the needs of the consumer and culture-oriented upper classes and economic growth sectors with the result being that the gap between rich and poor continues to grow. Such fragmented cities are a fragile entity in which conflicts are inevitable.

The Future Lies in the Cities of the World

Considering the fact that most people on the planet are city-dwellers, questions are starting to be asked about how to develop and design urbanisation and urban migration in a sustainable way. Urban residents the world over require good air to breathe, clean drinking water, access to proper healthcare, sanitary facilities and a reliable energy supply.

The current situation in cities in developing countries can be precarious: the air is thick enough to touch; sewage treatment plants, if any, are overloaded and industrial factories secrete virtually unregulated highly toxic waste and wastewater. In addition, climate change will likely hit poorer cities harder.

However, cities in the developed countries have to deal with environmental challenges in the areas of transport, energy and waste and wastewater. The only advantage here: the minimum supply of water, sanitation and energy already exists.

On an international level, there are countless efforts currently being undertaken to support sustainable urban development. A number of large UN projects, such as the UN-HABITAT-Programm Sustainable Urban Development Network (SUD-Net) or the Urban Management Programm (UMP), are endeavouring to improve and strengthen governmental and planning abilities. One of the goals of the UMP is to also implement the Millennium Development Goals at the city level.

Many urban problems can be explained not only at the city level, but must be regarded as results of political disorder and economic instability on a global and national level – and that this is where the solutions lie!

Want to know more about life in a megacity? This web documentary from the Deustche Welle allows you to accompany a young woman on her regular route to work as she naviagtes the traffic and transport chaos in Mumbai or wander through Mangueira, one of the favelas in Rio de Janeiro. This interactive map from the Guardian also walks users through some of the challenges and opportunities facing cities like Lagos, Dhaka and Mexico City.

Author: Indra Jungblut, RESET editorial. Translated by Anna Rees, RESET editorial

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