What Hope for What World?
Challenges Facing the World Today and Tomorrow
Our greatest hope is surely to see love put into practice for the good
of all living beings. Hope starts in the present and looks beyond
the problems and pain of today toward a better tomorrow, a
happier future for all. As Christ came for the salvation of all, so we
long to see the world renewed in hope for all. Therefore we sometimes
need to try to look beyond frontiers and barriers, to see the world as
a whole. What is the world like? What hope should we be looking
for?
The number of people in the world is growing, and
has grown very fast in recent decades. By 2012, there will be 7 billion
(7,000 million) people alive in the world, far more than double
the 3 billion of 1960. Yet in 80 countries the birth rate has now
fallen below that needed to maintain the present population and the
number of such countries is growing. In 1900, the average life
expectancy for the whole world was around 30 years, today it is 66
years. People are living longer almost everywhere. It is said that of
all the human beings who have ever lived to be 65, one half are alive
today. There are some fundamental statistics that we need to know
if we are to have a clear picture of the present situation of humanity
as a whole, and of the challenges facing our future.
What follows is information that is freely available
scattered across the Internet, mostly found through Wikipedia,
collected and ordered as clearly as possible. Of course, there are
ongoing debates about many details, and above all about what might be
the possible solutions to the problems that are going to arise in the
coming decades. But we often say that we are all “one human family” and
in a family people like to know about one another's age, health and
general well-being because they care about each other.
1. False Alarms
Are there “too many people” in the world? The short answer is “No,”
because the world could (at least in theory) support far more people
than are alive today. But ever since the Rev. Thomas Robert Malthus
(1766-1834) published his intensely pessimistic Essay on the Principles
of Population in 1798, the consequences of population growth have been
a source of anxiety and a subject of controversy. The word “Malthusian”
is today usually used negatively, being linked to what is known as
“eugenics,” practiced widely in the early 20th century especially, with
its grim policies of forced abortions and sterilizations, or even
genocide, often of defenseless, poor people, amidst notions of superior
and inferior races (or even classes).
In 1968, Paul R. Ehrlich gave a new life to
Malthus's arguments in The Population Bomb, predicting widespread
famines in the 1970s and 1980s. This gave a strong impetus to campaigns
designed to bring birth-control to “overpopulated,” poor nations, often
using considerable coercion. Still today, talk of a “population
explosion” tends to be tinged with racism and prejudice, implying more
or less explicitly that the “developed, civilized” nations of the North
risk being engulfed by vast numbers of people from poor, underdeveloped
countries further South. This is dangerous, and it is not true. The
population “explosion” is in a real sense over, although huge
challenges lie ahead.
2. Today's Realities
Certainly, there are a lot of people in the world today, and there are
more to come. In 1900, the total population of the world was about 1.6
billion (1,600 million), roughly double what it had been in 1750. In
1959, it was 3 billion and 40 years later, in 1999, it had doubled to 6
billion. By 2012 it will reach 7 billion. In 2010, on average 362,733
children were born every day, while 153,884 people die, a daily
increase of over 200,000 people. However, the growth rate of the
world's population peaked in 1962-3 at 2.20% per year. In 2009 the
estimated annual growth rate was 1.1%. The rate of growth is slowing
down almost everywhere and some projections suggest that the total rate
of growth may diminish to zero by 2050, representing a world population
plateau of 9.2 billion.
Today almost 3.8 billion people, over 60% of the
world's total population, live in Asia, (China and India alone house
40% of the world's population). Asia's proportion of the total world
population has barely varied over the course of the past 300 years.
Africa today has over 900 million people, 14% of the total. Europe's
710 million make up about 10%. North America has 514 million (8%),
South America 371 million (5.3%), and Australia 21 million (0.3%).
There have been some enormous changes in these
proportions in the last century. In 1900, Europe with just over 400
million people was home to nearly one quarter (25%) of the world's
total population, Africa with 133 million had only 8 percent, one third
of Europe's total. The African population more than tripled in the
second half of the 20th century, passing from 221 million in 1950 to
767 million in 1999. It is set to more than double, if not triple, in
the coming decades. Some projections suggest that by 2050, Africa will
have almost 3 times the population of Europe, which will have shrunk to
628 million. Latin & Central America experienced dramatic increases
in the same period, more than doubling from 74 million (4.5%) in 1900
to 167 million in 1950, then more than tripling to 511 million (8.5%)
in 1999.
Population growth depends on a number of major
factors. The first is the number of children born, the second is the
percentage of them that survive infancy, the third is the average life
expectancy of the population in each region of the world. Adequate
food, basic hygiene and essential medical care all play important roles.
Population by country
Growth rates
Percentage growth rates
3. Birth and Fertility Rates
The “Crude Birth Rate” is the number of children born in a country per
1,000 people per year. As of 2009, the average birth rate for the whole
world was 19.95 per year per 1000 total population, a 0.48% decline
from 2003's world birth rate of 20.43 per 1000 total population.
According to the World Factbook, the country with the highest birth
rate currently is Niger at 51 births per 1000 people. The country with
the lowest birth rate is Japan at 7.4 births per 1000 people. As
compared to the 1950s, when the world birth rate was at 36 births per
1000, the overall birth rate has declined by 16 births per 1000 people.
In more than 50 countries, virtually the whole developed world, the
rate is below 13 births per 1000, that for China being barely 12.
Crude birth rates
World Factbook birth rates
The total fertility rate (TFR) is the number of
children expected to be born per woman in her child-bearing years. At
present the projected world average TFR is 2.6 children. In 89
countries, more babies than this will be born on average, in 105, less
will be born. In the 15 or so countries where 6-7 babies is the
average, infant mortality is also high. All except Afghanistan are in
Africa.
There is a worldwide tendency for the TFR to
diminish. Today in at least 60 countries women have an average of less
than 2 babies. In 1950, the world average TRF was 4.92 but it is
projected by the UN that by 2050 it will be down to nearly 2.
Fertility rates
Total fertility rate
“Replacement fertility” is the total fertility rate
at which newborn girls would have an average of exactly one daughter
over their lifetimes. In other words, women would have just enough
babies to replace themselves. If there were no mortality in the female
population until the end of the childbearing years then the replacement
level of TFR would be very close to 2.0, but actually it needs to be
placed slightly higher because of the natural excess of boy over girl
births (to say nothing of selective abortions practiced in certain
countries that increase the proportion of boys even more). Taken
globally, the total fertility rate for replacement is reckoned at 2.33
children per woman. At this rate, global population growth would tend
towards zero. Currently, at least 80 countries are below this figure,
which means that in a few decades the total population of many
countries will begin to shrink unless there is massive immigration.
4. Infant Mortality
In the past, even European children were prone to die soon after birth.
The percentage of the children born in London who died before the age
of five is said to have decreased from 74.5% in 1730-1749 to 31.8% in
1810-1829. Today, the infant (under-one) mortality rate of the
world is 49.4 per 1000 according to the United Nations and 42.09 per
1000 according to the CIA World Factbook. The total under-five
mortality rate of the world today is 73.7 per thousand according to the
United Nations. The UN lists 136 countries with figures below this
average and 58 above, with all 58 recording at least 5% (50 per 1000
births) infant deaths, an additional 11 countries recording 5%
under-five mortality. 16 countries have more that 10% infant mortality
rates while 36 have more than 10% under-five mortality; 4 countries
have more than 20% under-five mortality. In 2008, 8.8 million children
under five died, down from 9.2 million in 2007, and 12.7 million in
1990. Approximately 60 countries make up 94% of under five child
deaths. Virtually all the countries with very high infant and
under-five mortality figures are in Africa, but Afghanistan is one of
the highest.
There are more than 50 countries in the world where
the death of a child is now a rare event, with infant mortality rates
below 10 per thousand.
Infant mortality
5. Life Expectancy and Median Age
In countries with high infant mortality rates, the figure for “life
expectancy at birth” is affected by the high rate of deaths in the
first few years of life. A considerably higher figure is obtained by
calculating “life expectancy after five.” By 2006 United Nations
statistics, the average life expectancy of the world taken as a whole
was 64.5 years for men and 68.8 for women, but there are large,
significant differences between countries and continents and even
within countries between regions or ethnic groups. In most countries
(about 130 in the UN list, 160 in the CIA list that includes smaller
dependencies) life expectancy is higher than the world average, while
it is lower in only 62. Almost all of the 62 are in the African
continent, where only the African countries along the Mediterranean
coast are above the world average. Most of the countries in the lowest
portion of the table are in Africa, and the level of HIV/AIDS in those
countries is often a major factor in early deaths, in addition to
poverty, malnutrition, and poor health care. In Zambia and Angola the
average life expectancy is under 40 and in Swaziland it is only a
little above 30, at the foot of the table. Of the countries in Europe,
Russia is lowest, close to the world average, mainly because its men
have a life expectancy of less than 60 compared to the 73 for women. By
comparison, it is usually thought that the world average life
expectancy in 1900 was 30.
Life expectancy (2010)
The “median age” of a country is the age that
divides its population into two numerically equal groups. There can be
few sets of population statistics with such wide extremes. Taking the
figures for whole populations (men and women have different life
expectancies and so different median ages), for 2010 Japan's median age
has been estimated as over 44.6 while that of Uganda is 15. For
most African countries it is 20 or below (meaning that half their total
population is below twenty), in virtually all of the most developed
countries it is 38 or above, but for some 30 developed countries,
mainly in Europe, it is already 40 or more, with a few like Germany and
Japan now rising to 44.
Median age (2010)
Natural population growth in most developed
countries has diminished to close to zero, without being held in check
by famine or lack of resources, as people in developed nations have
shown a tendency to have fewer children. The fall in population growth
has occurred at the same time as large rises in life expectancy in
these countries. Similar trends are now becoming visible in ever more
developing countries, with the median age rising in all but 18
countries. Far from spiraling out of control, world population growth
is expected to slow markedly. The United Nations Population Division
expects the absolute number of infants in the world to begin to fall by
2015, and the number of children under 15 by 2025.
6. Aging
People have never lived as long as they do now. Recent overall
increases in the average age of death, combined with sharp falls in the
birth rate, raise the prospect of the aging of the world's population
in the coming decades. Among the countries currently classified by the
United Nations as “more developed” (with a total population of 1.2
billion in 2005), the overall median age rose from 29.0 in 1950 to 37.3
in 2000, and is forecast to rise to 45.5 by 2050 . The corresponding
figures for the world as a whole are 23.9 in 1950, 26.8 in 2000, and
37.8 in 2050. The median age in Europe will increase from 37.7 years
old in 2003 to 52.3 years old by 2050. The 55 to 64 year old age
bracket in the European Union is now larger than the 15 to 24 year old
bracket. By 2050 the ratio of Europe's working age to senior age
population will decrease by 50%, two workers instead of four for every
retiree. It has been calculated that half of Spain's population will be
older than 55 by 2050, giving Spain the highest median age of any
nation in the world.
7. Women Make Choices
Starting in 2002, a very significant drop was detected in the fertility
rates of a broad spread of diverse countries spanning the developed and
developing world comprising half the world's population and with little
in common between their governments and social attitudes. In 1950,
worldwide the average woman had 5 children. Today she has just 2.3.
Although in many countries there are still a large number of people at
or below child-bearing age and actual birth rates will remain very high
for some years to come, this fall has already led to a downgrading of
future population predictions amid fears of a population crash, with
societies full of the elderly unable to support their own services.
There are degrees in the low birth rate. In Sweden
1.6 children are born per couple, Norway 1.8 and Britain and Finland
1.7, much closer to replacement than in many other developed nations.
The difference is largely because in such countries women have more
chance of combining a career with motherhood; people are more likely to
have set up home on their own before marriage, so are better accustomed
to house-work; and governments are better at helping couples combine
family and work. About half the jobs held by Swedish women are
part-time, creches are nearly universal and paid leave for a birth
lasts for a year. All this is unheard of in Italy, where only 12% of
employed women have part-time jobs, and in eastern Europe, where
fertility rates have plunged since the collapse of communism wrecked
state-funded family support services. Singapore's prime minister has
announced financial incentives for families, increased maternity leave,
and cut working hours so single people can meet more easily, in an
attempt to reverse the current low birth rate. It is too early to see
if he will succeed.
The demographer Peter McDonald argues that the very
low Southern European figures are a result of the lopsidedness of moves
to gender equality. Women have got the freedoms that arise from better
education and employment, he says, but not in their relations with
their men or in terms of state services for the family. Economic
liberalism has clashed with social conservatism. Jean-Claude Chesnais
goes further. With poor state child-care provision, and most men
unlikely to help in looking after their offspring, he says, “the
obstacles to childbearing in countries like Italy are enormous and the
economic sacrifices made by mothers are viewed as unbearable.”
The Mediterranean patriarchal model is far more
widespread than the northern European model of helpful husbands and
governments. McDonald says we can already see this in eastern Asia,
where conservative family values lie behind the ultra-low fertility
rates from Singapore to Shanghai to Tokyo. These low rates could bring
about a serious crash in populations. McDonald calculates that the
population of Italy is set to crash from 56 million now to just 8
million by 2100. Likewise Spain would lose 85 per cent of its
population within the same time frame and Germany 83 per cent. Some
find his figures to be exaggerated, but only to a degree.
One important factor is the age at which women begin
to bear children. Worldwide figures are hard to find, but along with
the United States, many other developed nations have observed increases
in average age at marriage and first birth between 1970 and 2006, with
a considerable number of West-European countries and Japan now
averaging 28-30 years of age. In 2006, about 1 out of 12 first births
in the US were to women aged 35 years and over, compared with 1 out of
100 in 1970. Increase in age at first birth, which affects the number
of children a woman will have during her childbearing years, has
important ramifications for family size and overall population change.
Female fertility starts declining after age 27 and drops at a somewhat
greater rate after age 35. Obviously, the reported worldwide
decline of male fertility due to a sedentary lifestyle (and perhaps
pollution of the food chain by growth hormones) will also have a
significant impact.
8. Population Density
There is a clear link between the population of a country, the area of
land it disposes of, and the number of people that land can support.
Many factors complicate the significance of raw figures, since
obviously large areas of desert, forest or mountain are going to be
virtually uninhabitable. Cities such as Singapore and Hong Kong are
notoriously densely populated for their size, as are small islands like
Malta, but these cannot be considered as “nations” in the usual sense.
The most densely populated country in the world is Bangladesh, whose
162 million people dispose of under 144,000 square kilometers,
resulting in a density of over 1,200/km2, while the next countries (not
smaller island-states) in the list are Taiwan (less than 640/km2) and
South Korea (486 /km2 ). The density of the Netherlands (400/km2) is
well-known but it is more alarming to realize that India is not much
less densely populated at 360/km2. In Europe, the United
Kingdom's 255/km2 contrast strongly with France's 113 and
Ireland's 63.
Certain major countries stand out by their low
population densities. Australia has about 3 people, Canada has
3.4, Russia has 8.3, New Zealand has 15.9, Brazil and Chile have
22.6, the United States of America have 32, South Africa has 40 people
/km2. No matter how harsh some of their terrain, there is clearly
still plenty of room there.
Population density
9. Environmental Issues
Universal, fundamental needs that are already under stress and will
become increasingly difficult to provide for everyone everywhere
include food, clean water, energy, sanitation, housing, education,
employment, and health-care. All are essential, either directly or,
like education and employment, important because without a minimum of
money many of the others are inaccessible, and for money a paid job is
usually necessary. That is one reason why so many young people leave
the rural village, heading for towns and cities where they can earn
money for their family's needs.
It is clear that any attempt to forecast the future
will be controversial. The entire issue of global warming and climate
change is a case in point. There can be little doubt that any
significant change in the world's climate or sea-levels will have an
impact on food supplies which are already fragile. However, there is
still too little certain information to allow detailed forecasts.
The related topic of carbon emission reduction is
similar. In 2005, China, the United States, the countries of the
European Union and Brazil were together responsible for over 50% of the
world's greenhouse gas emissions. Indonesia, Russia, India,
Japan, Canada made up another nearly 20%. Much of the total for Brazil
and Indonesia must be attributed to illegal forest-burning, not the use
of fossil-fuels. The reduction of greenhouse gas emissions is a policy
that all are committed to but which few governments place very high on
their agenda.
Another topic that will remain of vital importance
is that of energy sources, with the disputed issues of “peak oil” (the
point at which world oil production will begin to decline and prices
rise accordingly) and the development of alternative sources of energy.
Again, certain information is hard to come by although lip-service is
generally paid to the importance of exploiting sunlight, wind and tides
as sources of energy.
Greenhouse gas emissions
10. Malnutrition and food supplies
From 1950 to 1984, as the Green Revolution transformed agriculture
around the world, grain production increased by over 250%. The world
population has grown by about four billion since the beginning of the
Green Revolution and most believe that, without the Revolution, there
would be greater famine and malnutrition than the UN presently
documents.
The energy for the Green Revolution was provided by
fossil fuels in the form of fertilizers (natural gas), pesticides
(oil), and hydrocarbon-fueled irrigation. Critics point out the green
revolution relies too heavily on petroleum-based fertilizers,
irrigation, as well as machines for planting and harvesting. All
this needs money rather than many hands, and the rural birth-rate tends
to fall as a result.
The World Health Organization cites malnutrition as
the gravest single threat to the world's public health. The figures for
2007 already showed an actual increase in absolute numbers of
undernourished people in the world, 923 million in 2007 versus
832 million in 1995, with approximately 850 million people suffering
from chronic malnutrition in 2005, while FAO estimates pointed to an
even more dramatic increase, to 1.02 billion in 2009. On the average, a
person dies every second as a direct or indirect result of malnutrition
- 4000 every hour - 100 000 each day - 36 million each year - 58% of
all deaths (2001-2004 estimates). On the average, a child dies every 5
seconds as a direct or indirect result of malnutrition - 700 every hour
- 16 000 each day - 6 million each year - 60% of all child deaths
(2002-2008 estimates). Mortality due to malnutrition accounted for 58%
of the total world mortality in 2006. People living in urban housing
are rarely able to grow their own food and are obliged to earn enough
money to purchase almost all that they need. Full employment is
conditional on a healthy, growing economy. Any rise in the price of
essential foodstuffs is likely to provoke social unrest.
Malnutrition:
More precise statistics
11. Urbanization
The global proportion of urban population rose
dramatically from 13% (220 million) in 1900, to 29% (732 million) in
1950, to 49% (3.2 billion) in 2005. (It passed 50% in 2007.) The figure
is likely to rise to 70% by 2030. There are naturally large
differences between most developed and less developed countries in the
number of urban dwellers but the pattern is not entirely systematic,
with some African countries recording large urban populations (51% in
Ghana, over 58% in Angola and Cameroon, 62% in Congo) although most are
between 30 and 45%.
Northern and Western Europe with nearly 80% contrast
with the 67-69% of Eastern and Southern Europe. The 80% for Canada and
82% for the USA serve to remind us that huge areas of farmland and
wilderness do not provide much employment, a fact supported by
Australia's 89% of urban dwellers.
Urban population and rate of growth
Figures for 2005
12. Water
There is some really good news: 2 billion people have gained access to
a safe water source since 1990. The proportion of people in developing
countries with access to safe water is calculated to have improved from
30 percent in 1970 to 71 percent in 1990, 79 percent in 2000 and 84
percent in 2004, parallel with rising population. This wonderful trend
is projected to continue and in that sense there is not yet a water
crisis, but there are still grave problems affecting large numbers.
Waterborne diseases and the absence of sanitary
domestic water are one of the leading causes of death worldwide. For
children under age five, waterborne diseases are the leading cause of
death. At any given time, half of the world's hospital beds are
occupied by patients suffering from waterborne diseases. According to
the World Bank, 88 percent of all waterborne diseases are caused by
unsafe drinking water, inadequate sanitation and poor hygiene.
62% of the world's population has access to what WHO
/ UNICEF term “improved sanitation” (any sanitation method superior in
hygiene to the open pit) in 2008, up 8% since 1990. Only slightly
more than half of them or 31% of the world population lived in houses
connected to a sewer. Overall, 2.5 billion people lack access to
improved sanitation and thus must resort to open defecation or other
unsanitary forms, such as public latrines or open pit latrines. This
includes 1.2 billion people who have access to no facilities at all. In
developed countries, where less than 20% of the world population lives,
99% of the population has access to improved sanitation and 81% are
connected to sewers. Without proper sanitation, diseases proliferate.
In view of the grave health risks that result, one of the most
important problems still to be overcome must be provision of proper
sanitation for all.
Water deficits, which are already spurring heavy
grain imports in numerous smaller countries, may soon do the same in
larger countries, such as China and India. The water tables are falling
in scores of countries (including Northern China, the US, and India)
due to widespread overpumping using powerful diesel and electric pumps.
Other countries affected include Pakistan, Iran, and Mexico. This will
eventually lead to water scarcity and cutbacks in grain harvest. Even
with the over-pumping of its aquifers, China is developing a grain
deficit. When this happens, it will almost certainly drive grain prices
upward. Most of the 3 billion people projected to be added worldwide by
mid-century will be born in countries already experiencing water
shortages. I
It is already clear that the waste of precious fresh
water in sprinkled irrigation for crops cannot continue. Drop-by-drop
irrigation at ground level, directly above the roots of individual
plants, would save a very considerable quantity of water for human use.
Water deficits
13. Employment
Population in the sub-Saharan Africa where total fertility rates remain
at 5.4 is expected to rise from 667 million to 1,085 million by 2025.
The Middle East with fertility rates at 3.5 will also see very high
birth rates. Reports stress that these high rates will reduce economic
growth, stress environmental resources, and often young populations
with excess adolescent men cause political instability and violence.
Yet the presence of very many young people in a population can become a
positive factor if they have received proper education and live in a
forward-looking culture at a moment when new investments and economic
expansion create employment for them. Even working as unskilled and
semi-skilled laborers, they can embark on a meaningful life and help
their families.
The young people currently trying to leave Africa in
search of work in Europe or the Middle East are among the most
important resources of their countries; they have the ambition and the
dreams needed for change and progress, but find nothing is possible at
home. Immigration is their only hope and the fear of “invasion” often
expressed in parts of Europe is deeply misguided. They have much to
offer and their contribution to the European economy is increasingly
going to be urgently needed.
Equally important and uncertain is the future
direction of the world's economic system. It sometimes seems extremely
fragile, and the consequences of a severe failure would probably be
catastrophic on a large scale.
14. Fears and Hopes
Some very acute anxieties are inspired by these figures and forecasts.
The most fundamental ones are whether it will be possible to produce
enough food, water and energy for the world's growing population in the
coming decades. Related to that is the question of whether the young
adults of tomorrow will be able to find work to earn the money they
will need to purchase what they and their families need in order to
survive and flourish. Food, water, energy are commodities in a
commercialized world, and market forces are already driving up the
prices.
Perhaps the greatest challenge in the coming decades
will be ensuring that the young generations can find employment. This
is because of the probable consequences if large numbers of urban youth
find themselves unable to earn a sufficient wage by meaningful, regular
work. The spread of drugs, violence and crime, as well as of narrow
nationalism, religious fanaticism and intolerance, can be attributed to
the despair born of lives deprived of meaning and hope.
The Green Revolution, the enormous rise in life
expectancy almost worldwide, the fall in infant deaths, the increased
availability of clean drinking water, all show that much can be
achieved when many people make small but significant contributions
toward solving problems and challenges. There is certainly room for
hope, and in many countries the aging of the population promises to
change the level of consumerism and bring about a greater maturity in
governance.
Above all, the question arises of the standard of
living future generations should be able to enjoy. Today, millions take
for granted relatively cheap airfares, expect to be able to own a car
sooner or later, enjoy a varied diet at the expense of a great deal of
wasted food. In certain countries, mainly in western Europe, people
assume that their health problems will be treated more or less free of
charge and that they will not be abandoned in their old age. This is
already becoming less certain.
The question of global warming will become urgent;
it seems impossible to expect elected governments to take really
unpopular measures, yet much might have to change if there are global
rises in energy prices. The fall in the number of working people (and
thus of tax-income) in most developed countries will force cut-backs in
social services which are still taken for granted. The result might at
first be widespread protests, violence even, but there seems to be no
choice and the language of “live a simpler life” is going to become
increasingly powerful. There is a risk that small elites will
monopolize resources and privileges, living in protected enclaves while
the general population is forced to endure hardship. But that is the
stuff of science-fiction, and we must hope that humanity can find
humane solutions that will ensure a good life for all, even though it
might not be much like that enjoyed in the wealthiest nations today. It
should be much healthier and, hopefully, much happier, if people once
understand what it means to say, “No one is an island.”
To Know More
This text is intended to be a very simple introduction into some
complex and at times controversial areas. Each topic is treated more or
less at length in Wikipedia where usually there are additional links
for further research in each page.
United Nations Population Division home page:
http://www.un.org/esa/population/unpop.htm
United Nations Population Information Network
http://www.un.org/popin/
US Census Bureau
http://www.census.gov/
USA CIA World Fact Book
https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html
OXFAM
http://www.oxfam.org/
UNICEF
http://www.unicef.org/
UNAIDS
http://www.unaids.org/
World Health Organization
http://www.who.int/
World Population Counter
http://www.ibiblio.org/lunarbin/worldpop
Books by Fred Pearce offer reliable, readable summaries of the main challenges:
Peoplequake: Mass Migration, Ageing Nations and the Coming Population Crash. 2010.
ISBN: 978-1905811342
Last Generation - How Nature Will Take Her Revenge for Climate Change. 2007.
ISBN: 978-1903919880
When the Rivers Run Dry: What Happens When Our Water Runs Out? 2007.
ISBN: 978-1903919583