Off topic -- more on population growth (from NYT).
Experts Scale Back Estimates of World Population Growth
August 20, 2002
By BARBARA CROSSETTE
Demography has never been an exact science. Ever since
social thinkers began trying to predict the pace of
population growth a century or two ago, the people being
counted have been surprising the experts and confounding
projections. Today, it is happening again as stunned
demographers watch birthrates plunge in ways they never
expected.
Only a few years ago, some experts argued that economic
development and education for women were necessary
precursors for declines in population growth. Today,
village women and slum families in some of the poorest
countries are beginning to prove them wrong, as fertility
rates drop faster than predicted toward the replacement
level - 2.1 children for the average mother, one baby to
replace each parent, plus a fraction to compensate for
unexpected deaths in the overall population.
A few decades ago in certain countries like Brazil, Egypt,
India and Mexico fertility rates were as high as five or
six.
As a result, United Nations demographers who once predicted
the earth's population would peak at 12 billion over the
next century or two are scaling back their estimates.
Instead, they cautiously predict, the world's population
will peak at 10 billion before 2200, when it may begin
declining.
Some experts are wary of too much optimism, however. At the
Population Council, an independent research organization in
New York, Dr. John Bongaarts has studied population
declines in various countries over the last half century.
He questions the assumption that when fertility declines
begin they will continue to go down at the same pace,
especially if good family planning services are not widely
available.
Sharp fertility declines in many industrialized and
middle-income countries had already challenged another old
belief: that culture and religion would thwart efforts to
cut fertility. In Italy, a Roman Catholic country whose big
families were the stuff of cinema, family size is shrinking
faster than anywhere else in Europe, and the population is
aging rapidly as fewer children are born. Islamic Iran has
also had great success with family planning.
"Projections aren't terribly accurate over the long haul,"
said Dr. Nicholas Eberstadt, a demography expert at the
American Enterprise Institute in Washington. "Demographers
have been surprised by just about every big fertility
change in the modern period. Demographers didn't anticipate
the baby boom. They did not anticipate the subsequent
decline in fertility in industrialized Western
democracies."
What's next? Demographers can agree generally on a few
measurable facts and some trends. The world's population,
now 6.2 billion, quadrupled in the 20th century, and
changed in drastic ways. In 1900, 86 percent of the world's
people lived in rural areas and about 14 percent in urban
areas. By 2000, urban communities were home to 47 percent
of the population, with 53 percent still in the
countryside.
Between now and 2030, when the global population is
expected to reach about eight billion, almost all the
growth will be in cities. But urbanization is not
necessarily a bad thing for the environment, said Dr.
Joseph Chamie, director of the United Nations' population
division.
"Moving to cities frees up the land for forestry,
agriculture and many other activities," Dr. Chamie said.
"You're getting people concentrated, so you can probably
recycle more easily. People change their lifestyles. The
Indian moving from the boonies of Uttar Pradesh to the city
of Lucknow gets educational opportunities, cultural
opportunities, all sorts of political participation. He can
be influenced by advertising and public relations
campaigns. Immunization will be better, and family
planning."
As births fall and lives are extended, the global
population is getting older. The over-80 age group is the
fastest growing.
But not everywhere. For example, the United Nations
calculates that life expectancy at birth is being slashed
in countries hardest hit by AIDS. In South Africa, the life
of a baby born now should be 66 years; AIDS has cut that to
47. In Zimbabwe, the drop has been to 43 years from 69. In
Botswana, it is 36 years, down from 70.
Another cautionary sign from projections is that where
populations are continuing to grow fastest, societies and
governments may be least likely to cope with the results,
including strains on natural resources - farmland, water,
air, forests and animals.
Last year, the organization published a report and wall
chart, "Population, Environment and Development," plotting
and analyzing population changes as its contribution to the
debate surrounding the Johannesburg summit meeting.
The United Nations estimates that the world's current
population, 6.2 billion, is growing at an annual rate
slightly over 1.2 percent, producing some 77 million
people. Of this growth, 97 percent is taking place in
less-developed countries, said Dr. Chamie, whose position
at the United Nations makes him chief keeper of the world's
statistics. Six nations will dominate this growth, and in
this order: India, China, Pakistan, Nigeria, Bangladesh and
Indonesia.
Thus, though fertility is declining unexpectedly in a poor
country like India, which has more than a billion people,
the actual numbers continue to rise rapidly because the
base is so large. India is gaining as many people annually
as China, Pakistan and Nigeria combined, the United Nations
says.
India is projected to have at least 100 million more people
than China by 2050, even if China's one-child policy is
relaxed. Small families are now the norm for the Chinese,
whose standard of living has risen above that of the people
of India by many measures.
Among industrialized countries, the United States alone has
a growth rate comparable to that of developing nations. It
now ranks seventh in growth, Dr. Chamie said, but 80
percent of that growth comes from immigration. In Europe,
populations are shrinking, even with more immigration.
With much of the population bulge predicted in Asia, the
East-West Center in Honolulu has just published a report,
"The Future of Population in Asia," which finds cause to
fear considerable environmental stress in a region where
population densities and numbers are often great. Asia, the
report notes, already has 56 percent of the world's
population living on 31 percent of its arable land, and
more than 900 million people exist on less than $1 a day.
"Asia faces the most acute pressure on arable agricultural
land of any region in the world," the report says, adding
that expansion of farmland has been made at the cost of
forests. Acute water scarcity, a significant loss of
biodiversity and more urban pollution seem inevitable.
Twelve of the world's 15 most polluted cities are in Asia.
By 2020, the report predicts, Asia will be producing more
carbon dioxide emissions than any other region.
"When looking at current and future environmental concerns
in Asia," the report concludes, "the number of people to be
fed, clothed, housed, transported, educated and employed
may not be the only issue, but it is an issue that cannot
be ignored."
Copyright 2002 The New York Times Company. |
