15
© The Author(s) 2018
H. Komiyama, K. Yamada, New Vision 2050, Science for Sustainable Societies,
https://doi.org/10.1007/978-4-431-56623-6_2
Chapter 2
Progress on Vision 2050 Since 1995
2.1 Saturation of Man-Made Objects and the MaterialCirculating System
2.1.1 Saturation of Population
“Saturation” is a basic concept that expresses the conditions of the twenty-first century. The world’s population will also eventually reach saturation. Certainly, the
U.N. projects the global population to continue growing in the twenty-first century.
However, the root cause of this is the growth in average life-span. Population size is
determined by the number of childbirths and average life-span, and the number of
births in the world, excluding Africa, is already declining.
Each woman needs to give birth to two children—strictly speaking, 2.07 children
due to the fact that more males are born than females—in order to sustain the population of a country. Few developed countries exceed that replacement rate of two,
and those that do, do it just barely. Fertility rates continue to decline annually even
in such countries categorized as newly industrialized like Mexico, Brazil, Thailand,
and Indonesia. As of 2013, the rates for each stood at 2.19, 1.80, 1.40, and 2.34,
respectively. That is, for populations outside of Africa, when the average life-span
reaches saturation, they start to shrink.
In nearly every part of the world, the number of children born falls as the economy develops. The reasons for this are said to include a fading of the motivation to
have children as a source of labor, an inability to withstand the burdens of having
multiple children such as the costs incurred in providing their education, and people
being more knowledgeable about such things as contraception. Furthermore, it is
also known for a fact that as education – particularly that of women – becomes more
widely available, it causes the fertility rate to drop.
Accordingly, if economic growth remains steady in Africa, and if education levels in particular make rapid strides there, then the number of births will reach
© The Author(s) 2018
H. Komiyama, K. Yamada, New Vision 2050, Science for Sustainable Societies,
https://doi.org/10.1007/978-4-431-56623-6_2
Chapter 2
Progress on Vision 2050 Since 1995
2.1 Saturation of Man-Made Objects and the MaterialCirculating System
2.1.1 Saturation of Population
“Saturation” is a basic concept that expresses the conditions of the twenty-first century. The world’s population will also eventually reach saturation. Certainly, the
U.N. projects the global population to continue growing in the twenty-first century.
However, the root cause of this is the growth in average life-span. Population size is
determined by the number of childbirths and average life-span, and the number of
births in the world, excluding Africa, is already declining.
Each woman needs to give birth to two children—strictly speaking, 2.07 children
due to the fact that more males are born than females—in order to sustain the population of a country. Few developed countries exceed that replacement rate of two,
and those that do, do it just barely. Fertility rates continue to decline annually even
in such countries categorized as newly industrialized like Mexico, Brazil, Thailand,
and Indonesia. As of 2013, the rates for each stood at 2.19, 1.80, 1.40, and 2.34,
respectively. That is, for populations outside of Africa, when the average life-span
reaches saturation, they start to shrink.
In nearly every part of the world, the number of children born falls as the economy develops. The reasons for this are said to include a fading of the motivation to
have children as a source of labor, an inability to withstand the burdens of having
multiple children such as the costs incurred in providing their education, and people
being more knowledgeable about such things as contraception. Furthermore, it is
also known for a fact that as education – particularly that of women – becomes more
widely available, it causes the fertility rate to drop.
Accordingly, if economic growth remains steady in Africa, and if education levels in particular make rapid strides there, then the number of births will reach