While the world population has been on a constant increase in recent years, led by population growth in Asia and Africa, areas of residence have been rapidly urbanized. A report by the United Nations Population Fund shows that in 2009, 3.4 billion people, or about half of the world's population, are living in urban areas. The urbanization trend is likely to continue going forward, with about 5.0 billion people expected to live in urban areas by 2030 and about 6.4 billion people, or about 70% of the world population, by 2050 (Figure Int.-2-5). This trend of urbanization is particularly noticeable in developing regions such as Asia and Africa (Figure Int.-2-6).

The rapid urbanization in developing regions tends to adversely affect the environment.

On the consumption front, in tandem with urbanization-triggered changes in lifestyles, massive amounts of wastes and domestic effluents are generated in association with mass consumption, heightening the so-called domestic environmental load. In developing regions, on the other hand, the introduction of decontamination technologies is generally insufficient in secondary industries responsible for mass production that supports rapid economic development, raising concern that effluents and wastes generated in production activities are not being treated adequately.

In economic and industrial aspects, economic development accelerates the shift to tertiary

Figure Int.-2-4 Trends of Japan's Total Population and Population Growth Rate

Source: Prepared by the Ministry of the Environment based on Statistics Bureau, Ministry of Internal Affairs and Communications, "National Population Census" & National Institute of Population and Social Security Research, "Estimation of Future Population"

Figure Int.-2-5 Projected Urban and Rural Populations in the World and the Ratio of Urban Population (Thousands)

Source: Prepared by the Ministry of the Environment based on U.N. Population Division, "World Urbanization Prospects: The 2007 Revision Population Database"

industries, raises the economic dependence on overseas as well as on informal sectors, and increases demand for labor in urban areas. The attendant rapid population influx into cities leads to excessive urbanization, and administrative measures to deal with unemployment and residential areas turning into slums are likely to squeeze public coffers, causing chronic delays in infrastructure development.

Furthermore, urbanization, accompanied by motorization, in developing countries and suburbanization that comes with it would increase the environmental load from traffic congestion and carbon dioxide emissions, exacerbated by the lack of adequate infrastructures.

In Japan, the status of urbanization is somewhat different from global trends. While Japan's urban population is expected to remain stable at around 85 million in 2010 onward, the rural population is forecast to trend sharply lower (Figure Int.-2-7). This indicates the decline in the population is going to affect rural areas more than urban areas. In rural areas, therefore, problems with environmental conservation due to the shortage of people who conserve and manage satochi-satoyama (community-based forest areas and the surrounding countryside) and problems of "marginal settlements" stemming from the aging population are feared to grow more serious.

Figure Int.-2-6 Trends of Urban Population by Region (1950-2050)

Source: Prepared by the Ministry of the Environment based on U.N. Population Division, "World Urbanization Prospects: The 2007 Revision Population Database"

Figure Int.-2-7 Projected Urban and Rural Populations in Japan and the Ratio of Urban Population

Source: Prepared by the Ministry of the Environment based on U.N. Population Division, "World Urbanization Prospects: The 2007 Revision Population Database"