Economic and Social Affairs of the United Nations Secretariat,
The World at Six Billion. (ESA/P/WP.154), 12 October 1999.
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According to the latest United Nations population estimates, world
population reaches the six billion mark on 12 October 1999, an historic
milestone in the growth of world population. The marking of a world of six
billion just at the dawn of the new millennium is a convergence of events that
is attracting widespread global attention. The World at Six Billion was prepared
in response to this attention. It provides in tabular and graphic form salient
characteristics of past, current and future world population growth.
The twentieth century has witnessed extraordinary population growth. During this
century, world population increased from 1.65 billion to 6 billion, and
experienced both the highest rate of population growth (averaging 2.04 per cent
per year) during the late 1960s, and the largest annual increment to world
population (86 million persons each year) in the late 1980s.
The world population growth rate has fallen from its peak of 2 per cent per year
to around 1.3 per cent today. Nonetheless, world population will continue to
increase substantially during the twenty-first century. United Nations
projections (medium fertility scenario) indicate that world population will
nearly stabilize at just above 10 billion persons after 2200.However, the
twenty-first century is expected to be one of comparatively slower population
growth than the previous century, and be characterized by declining fertility
and the ageing of populations.
At the same time that the world population growth rate has declined from its
peak, the average number of children per couple has fallen from 4.9 to 2.7 and
life expectancy at birth has risen from 56 years to 65 years. The share of the
world's population living in urban areas has increased from 36 per cent to 47
per cent and the number of megacities of 10 million persons or more has grown
from 5 to 18.The number of persons who have moved to another country has risen
to over 125 million today.
In the less developed regions, couples are currently having about two children
less than couples did three decades ago. Even though fertility has declined to
relatively moderate levels in many developing countries, and to below
replacement level in some, a large and growing number of births are occurring
annually, due to the continued growth in the number of women of childbearing
age; a legacy of past high fertility levels. In the more developed regions,
fertility declined from 2.4 births per woman during the late 1960s to an
historic low of 1.6 for the current period. In Europe, Northern America and
Japan, the current fertility rate is 1.5 births per woman or below.
In spite of the impressive gains in health and life expectancy that the world
has exhibited during the past decades, much remains to be done. Recent years has
shown a devastating toll from AIDS in a number of countries, particularly in
sub-Saharan Africa. In addition, in some countries of Eastern Europe, the health
situation has been deteriorating and adult mortality, especially among males,
has increased.
The twentieth century has witnessed the growth of urban centres and the
concentration of population in urban areas. Half of the world population is
expected to be urban by 2006.Giant urban agglomerations are becoming both more
numerous and larger in size.
Another major transformation of the twentieth century has been population
ageing. In 1999 there were 593 million persons aged 60 years or over in the
world, comprising 10 per cent of the world population. By 2050, this figure will
triple to nearly 2 billion older persons, comprising 22 per cent of the world
population. This changing age structure will have wide-ranging economic and
social consequences, affecting such factors as economic growth, savings and
investment, labour supply and employment, pension schemes, and health and
long-term care. While once limited to developed countries, concern for the
consequences of ageing has spread to developing countries.
This publication provides a set of boxes, figures and tables that provides
country and regional and world-level data on population and demographic trends
and corresponding population policies. The population and demographic data are
taken largely from the official United Nations population estimates and
projections prepared biennially by the Population Division for the United
Nations system and are the consistent set of population numbers utilized by the
United Nations system. Projections are from the medium-fertility scenario. Other
scenarios, in particular the high and low, appear in other publications of the
United Nations Population Division. Policy information is from the Population
Policy Data Bank maintained by the Population Division for the United Nations.
The full set of references used when compiling this publication is given in the
Bibliography section at the end of the volume.
These boxes, figures and tables are intended to provide readers with an overview
of the startling changes in the population and demography of the world during
the twentieth century and earlier, and insight into how the world's demographics
will change during the twenty-first century.
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Published in: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, The World at Six Billion. (ESA/P/WP.154), 12 October 1999. |