*3.1.3 Other types of pollution*

*Sustainability in Urban Planning and Design*

pre-historic period of 2350–1800 B.C.

global South urbanization is fraught with many challenges in virtually every facet of the society due to its rapid rate and the governments' unpreparedness for the challenges. The urbanization challenge focus of this work is on the urban economy and its effect on the urban environment. Urbanization in the global South has had a great toll on the economy. The influx of people to urban areas in the South has led to constant increase in the level of unemployment. As the population increase has not been matched with commensurate growth in gross national product (GDP) and employment provisions both by the government and the private sector resulting in high level of unemployment with many urban residents resorting to the informal economy. The urban informal economy characterized by unregistered and unregulated businesses, has become the sole resort for many urban residents. This informal economy has been traced to some government policies and international economic policies which have affected the global South nations more than the developed global North nations. One of the major policies that have influenced and sustained the informal economy is neo-liberalism. Going through history, one can glean insights on how humankind and their groups have identified and reacted to threats and openings which were embedded in their natural settings. Urbanization, in this case, is seen as one of three fundamental approaches in history employed by humans towards problem solving. This particular approach involves movement of people from areas of scarcity and lack to areas of available resources. As for the actual timing of when urbanization started, it is believed to date back as far as the

Urbanization is not restricted to any particular region of the world; however, the rate at which urbanization is taking place is seen to be fastest in global south cities of Africa, Latin-America, Asia, the Pacific and the Caribbean. The United Nations (UN) projection is that higher than 4 billion or 77% of urban residents of the world will be in less developed regions in 2025. This figure will translate to a total increase of 186% or an equivalent of 2.61 billion new urbanities in Latin America, Asia and Africa starting from 1990. The State of World Population indicates that in year 2009, urbanization level in less developed countries stood at 45 and 29% in least developed countries. The growth rate of urban population in the same report indicates 2.6% for less developed countries and 4.1% for least developed countries

A greater percentage of people who move from rural to urban areas find themselves living in harsh or extreme conditions, more often than not, in the worst areas of cities. Such areas are often characterized by slums and squatter settlements. Houses in these areas are mostly shacks and cheap self-made apartments of mud, wood and zinc, corrugated iron sheets, etc. The most unfortunate ones are completely homeless or just manage to put up anywhere possible in global South cities

Urbanization has both negative and positive effects on global South cities, though, discussions in this respect often tilt towards the negative effects. The negative effects will be addressed along two broad areas of environment and economy.

Urbanization effects on the environment of global South cities come in two major ways: air and water pollution. The hallmark of cities and towns is the existence of automobiles and factories. As more people move into cities, larger quantities of dangerous gases such as carbon-dioxide, carbon-monoxide and

**36**

annually.

like in Nigeria.

*3.1.1 Environment*

**3.1 Effects of urbanization**

There are a number of other types of pollution which urbanization brings in its wake. They include traffic congestion which comes with the inevitable increase in various kinds of automobiles such as pedicabs; noise pollution which result from extra noise from small production units established by the migrants; inconvenience to pedestrians as they struggle with hawkers and street vendors; and a host of other types of environmental pollution. Another ancillary urbanization issues is the emergence of urban sprawls. This requires special mention as a form of environmental adverse effect of urbanization. The reason is that urban sprawls are not part of the original urban planning policy of any city. A sprawl indicates an increase in space or adjoining area of a city. Sprawls provide a haven for a plethora of informal economic activities which put pressure on the facilities meant for formally planned segments of the cityscape.
