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PUTTING THE BITE ON PLANET
EARTH:

Rapid Human Population Growth is Devouring
Global Natural Resources

By Don Hinrichson

The United Nations International Conference on Population and
Development (ICPD) convenes in Cairo, Egypt, this September,
gathering political readers from around the globe to explore how
human population growth is likely to affect society and the
environment, among other topics. One of the policy issues
participants will discuss is the links between human population,
sustainable development and the environment. In anticipation of
the event, International Wildlife turned to Don Hinrichson, a UN
consultant on environment and population issues, for this special
report on the connections between human expansion and natural
resources:

Each year, about 90 million new people join the human race.
This is roughly equivalent to adding three Canadas or another
Mexico to the world annually, a rate of growth that will swell
human numbers from today's 5.6 billion to about 8.5 billion
by 2025.

These figures represent the fastest growth in human numbers
ever recorded and raise many vital economic and environmental
questions. Is our species reproducing so quickly that we are
outpacing the Earth's ability to house and feed us? Is our
demand for natural resources destroying the habitats that give us
life? If 40 million acres of tropical forest—an area
equivalent to twice the size of Austria—are being destroyed
or grossly degraded every year, as satellite maps show, how will
that affect us? If 27,000 species become extinct yearly because
of human development, as some scientists believe, what will that
mean for us? If nearly 2 billion people already lack adequate
drinking water, a number likely to increase to 3.6 billion by the
year 2000, how can all of us hope to survive?

The answers are hardly easy and go beyond simple demographics,
since population works in conjunction with other factors to
determine our total impact on resources. Modern technologies and
improved efficiency in the use of resources can help to stretch
the availability of limited resources. Consumption levels also
exert considerable impact on our resource base. Population
pressures work in conjunction with these other factors to
determine, to a large extent, our total impact on resources.

For example, although everyone contributes to resource waste,
the world's bottom-billion poorest and top-billion richest do
most of the environmental damage. Poverty compels the world's
1.2 billion bottom-most poor to misuse their environment and
ravage resources, while lack of access to better technologies,
credit, education, health care and family-planning condemns them
to subsistence patterns that offer little chance for concern
about their environment. This contrasts with the richest 1.3
billion, who exploit and consume disproportionate amounts of
resources and generate disproportionate quantities of waste.

One example is energy consumption. Whereas the average
Bangladeshi consumes commercial energy equivalent to three
barrels of oil yearly, each American consumes an average of 55
barrels. Population growth in Bangladesh, one of the poorest
nations, increased energy use there in 1990 by the equivalent of
8.7 million barrels, while U.S. population growth in the same
year increased energy use by 110 million barrels. Of course, the
U.S. population of 250 million is more than twice the size of the
Bangladeshi population of 113 million, but even if the
consumption figures are adjusted for the difference in size, the
slower growing U.S. population still increases its energy
consumption six or seven times faster yearly than does the more
rapidly growing Bangladeshi population.  

In the future, the effects of population growth on natural
resources will vary locally because growth occurs unevenly across
the globe. Over the course of the 1990s, the Third World's
population is likely to balloon by more than 900 million, while
the population of the developed world will add a mere 56 million.
Asia, with 3.4 billion people today, will have 3.7 billion by the
turn of the century; Africa's population will increase from
700 million to 867 million; and Latin America's from 470
million to 538 million. By the year 2000, the Third World's
total population is expected to be nearly 5 billion; only 1.3
billion people will reside in industrialized countries.

The United Nations estimates that world population will near
11.2 billion by 2100. However, this figure is based on the
assumption that growth rates will drop. If present rates
continue, world population will stand at 10 billion by 2030 and
40 billion by 2110.

The United Nations Population Fund estimates that to achieve
the 11.2 billion projection, the number of couples using family
planning services—such as modern contraceptives—in
the developing world will have to rise to 567 million by the year
2000 and to 1.2 billion by 2025. In sub-Saharan Africa this means
a 10-fold increase by 2025 in the number of people who use family
planning. If these measures do not succeed, human population
growth could blast the 11.2 billion figure clear out of the ball
park.

Perhaps the most ominous aspect of today's unprecedented
growth is its persistence despite falling annual population
growth rates everywhere except in parts of Africa, the Middle
East and South Asia. Annual global population growth stands at
1.6 percent, down from 2 percent in the early 1970s. Similarly,
the total fertility rate (the average number of children a woman
is likely to have) has dropped from a global average of six only
three decades ago to slightly more than three today.

Population continues to grow because of tremendous demographic
momentum. China's annual growth rate, for example, is only
1.2 percent. However, the country's huge population
base—1.2 billion people—translates this relatively
small rate of growth into a net increase in China's
population of around 15 million yearly. Clearly, any attempt to
slow population growth is a decades-long process affected by
advances in medicine, extended life spans and reduced infant,
child and maternal mortality.

The following pages survey the effects of human population
growth on a wide range of natural resources.

Plants and Animals: The Shrinking Ark

Biologists have catalogued 1.7 million species and cannot even
estimate how many species remain to be documented. The total
could be 5 million, 30 million or even more. Yet, we are driving
thousands of species yearly to extinction through thoughtless
destruction of habitat.

A survey conducted recently in Australia, Asia and the
Americas by the International Union for Conservation of Nature
and Natural Resources—The World Conservation Union (IUCN)
found that loss of living space affected 76 percent of all mammal
species. Expansion of settlements threatened 56 percent of mammal
species, while expansion of ranching affected 33 percent. Logging
and plantations affected 26 percent.

IUCN has declared human population growth the number one cause
of extinctions. The 10 nations with the worst habitat destruction
house an average of 189 people per square kilometer (250 acres),
while the 10 that retain the most original habitat stand at only
29 people per square kilometer.

Future population growth poses a serious threat to wildlife
habitat. Every new person needs space for housing, food, travel,
work and other needs. Human needs vary widely from place to
place, but a US survey found that the average person requires
about 0.056 hectares (a hectare is a standard unit of land
measurement equal to about 2.47 acres) of nonfarm land for daily
living. To this must be added land for food production. This
varies with land quality and available technologies, but each
newborn person probably will need at least 0.2 hectare of
cropland unless food production per acre increases in the years
ahead. This will require the conversion of more and more wildland
into cropland. In East Asia, for example, the amount of
irrigated, high-yield cropland per person is already near the 0.2
hectare limit.

UN consultant and author Paul Harrison estimates, very
conservatively, that each new person will need at least a quarter
of a hectare. Thus, every billion people that we add to the
planet in the years ahead will require 250 million hectares more
of agricultural land. Most of this land will have to come from
what is currently wildlife habitat. The UN's projected
population of 11.2 billion by 2100 would require creation of
roughly 20 million square kilometers (8 million sq. ml.) of new
cropland—equivalent to more than 80 percent of all forest
and woodland in developing countries today.  

Conversion of natural habitat for human use can even reduce
the value of remaining wild areas for wildlife. When development
chops wild lands into fragments, native species often decline
simply because the small remnants do not meet their biological
needs. For example, studies of U.S. forest birds indicate that
species that prefer to nest in forest interiors are more subject
to predation and lay fewer eggs when habitat fragmentation forces
them to nest along forest edges. A study in southern California
indicated that most canyons lose about half of native bird
species dependent on chaparral habitat within 20 to 40 years
after the canyons become isolated by development, even though the
chaparral brush remains. Biologist William Newmark's 1987
study of 14 Canadian and U.S. national parks showed that 13 of
the parks had lost some of their mammal species, at least in part
because the animals could not adapt to confinement within parks
surrounded by developed land.

Habitat loss in North America and in Latin American tropics
has caused declines in many bird species that migrate between
those regions. The Breeding Bird Survey, a volunteer group that
tabulates nesting birds each June, found that 70 percent of
neotropical migrant species monitored in the eastern United
States declined from 1978 to 1987. So did 69 percent of monitored
neotropical migrants that nest in prairie regions. Declining
species include such familiar songbirds as veeries, wood
thrushes, blackpoll warblers and rose-breasted grosbeaks. As
human population growth continues to push development into wild
areas, fragmentation will increase and its effects on wildlife
survival will intensify.

Land Loss: A Food Crisis

Land degradation, a global problem, is becoming acute in much
of the developing world. Population pressures and inappropriate
farming practices contribute to soil impoverishment and erosion,
rampant deforestation, overgrazing of common lands and misuse of
agrochemicals.

Worldwide, an estimated 1.2 billion hectares, an area about
the size of China and India combined, have lost much of their
agricultural productivity since 1945. Every year, farmers abandon
about 70,000 square kilometers (27,000 sq. ml.) of farmland
because soils are too degraded for crops.

Drylands, including grasslands that provide rich pastures for
livestock, have been hardest hit. Although not as extensive as
once thought, desertification—the ecological destruction
that turns productive land into deserts—still threatens the
Middle East and parts of Africa and Asia.

Because of land degradation, large portions of the Sahel,
including Burkina Faso, Chad, Mali, Mauritania, Niger and
Senegal, can no longer feed their people. Although annual
fluctuations in rainfall may interrupt the trend of cropland
loss, the Sahel could suffer agricultural collapse within a
decade. Sahelian croplands, as presently farmed, can support a
maximum of 36 million people. In 1990 the rural population stood
at an estimated 32 million and will exceed 40 million by the end
of the decade even if annual population growth slows from the
current 3 percent to 2 percent.

Since 1961, food production has matched world population
growth in all developing regions except sub-Saharan Africa. In
the early 1980s, the UN Food and Agriculture Organization (FAO)
predicted that more than half of all developing nations examined
in its study of carrying capacity (62 out of 115) may be unable
to feed their projected populations by 2000 using current farming
technology. Most of the 62 countries probably will be able to
feed less than half of their projected population without
expensive food imports.

As a direct result of population growth, especially in
developing nations, the average amount of cropland per person is
projected to decline from 0.28 hectares in 1990 to 0.17 by
2025.

Three factors will determine whether food production can equal
population growth:

1. New Croplands. Currently, the amount of new land put into
production each year may equal the amount taken out of production
for various reasons, such as erosion, salt deposits and
waterlogging. Thus, the net annual gain in arable land, despite
wide-spread habitat destruction to create it, may be zero.

2. New Water Sources. Agricultural demand for water is
expected to double between 1970 and 2000. Already more than 70
percent of water withdrawals from rivers, underground reservoirs
and other sources go to crop irrigation.

3. Agrochemical Use. Pesticides and fertilizers are boosting
crop yields. However, in many areas agrochemicals are too
expensive to use, while in other areas they are overused to prop
up falling yields. Agrochemicals can pose health hazards,
creating another expense for developing nations.

Forest: The Vanishing World

The quest for more crop and grazing land has sealed the fate
of much of the world's tropical forests. Between 1971

and 1986, arable land expanded by 59 million hectares, while
forests shrank by at least 125 million hectares. However,
consultant Harrison estimates that during the same period, land
used for settlements, roads, industries, office buildings and
other development expanded by more than 50 million hectares as a
result of growth in urban centers, reducing the amount of arable
land in surrounding areas. Consequently, the amount of natural
habitat wiped out to produce the 59-million-hectare net in arable
land may have exceeded 100 million hectares.

If current trends continue, most tropical forests will soon be
destroyed or damaged beyond recovery. Of the 76 countries that
presently encompass tropical forests, only four—Brazil,
Guyana, Papua New Guinea and Zaire—are likely to retain
major undamaged tracts by 2010, less than a generation away.

Population pressure contributes to deforestation not only
because of increased demand for croplandand living space but also
because of increased demand for fuelwood, on which half of the
world's people depend for heating and cooking. The majority
of sub-Saharan Africa's population is dependent on fuelwood:
82 percent of all Nigerians, 70 percent of Kenyans, 80 percent of
all Malagasies, 74 percent of Ghanaians, 93 percent of
Ethiopians, 90 percent of Somalians and 81 percent of
Sudanese.

By 1990, 100 million Third World residents lacked sufficient
fuelwood to meet minimum daily energy requirements, and close to
1.3 billion were consuming wood faster than forest growth could
replenish it. On average, consumption outpaces supply by 30
percent in sub-Saharan Africa as a whole, by 70 percent in the
Sudan and India, by 150 percent in Ethiopia and by 200 percent in
Niger. If present trends continue, FAO predicts, another 1
billion people will be faced with critical fuelwood shortages by
the end of the decade. Already, growing rings of
desolation—land denuded for fuelwood or building
materials—surround many African cities, such as Ouagadougou
in Burkina Faso, Niamey in Niger and Dakar in Senegal. By 2000,
the World Bank estimates, half to three-quarters of all West
Africa's fuelwood consumption will be burned in towns and
cities.

According to the World Bank, remedying the fuelwood shortage
will require planting 55 million hectares—an area nearly
twice the size of Italy—with fast-growing trees at a rate
of 2.7 million hectares a year, five times the present annual
rate of 555,000 hectares.

Troubled Oceans: Disappearing Resources

Population and development pressures have been mounting in
coastal areas worldwide for the past 30 years, triggering
widespread resource degradation. Coastal fisheries are
overexploited in much of Asia, Africa and parts of Latin America.
In some cases—as in the Philippines, Indonesia, Malaysia,
China, Japan, India, the west coast of South America, the
Mediterranean and the Caribbean economically important fisheries
have collapsed or are in severe decline. "Nearly all Asian
waters within 15 kilometers of land are considered
overfished," says Ed Gomez, director of the Marine Science
Institute at the University of the Philippines in Manila.

Overfishing is not the sole cause of these declines. Mangroves
and coral reefs— critical nurseries for many marine species
and among the most productive of all ecosystems—are being
plundered in the name of development.

In 1990, a UN advisory panel, the Group of Experts on the
Scientific Aspects of Marine Pollution (GESAMP), reported that
coastal pollution worldwide had grown worse over the decade of
the 1980s. Experts pointed to an overload of
nutrients—mainly nitrogen and phosphorus from untreated or
partially treated sewage, agricultural runoff and
erosion—as the most serious coastal pollution problem.
Human activities may be responsible for as much as 35 million
metric tons of nitrogen and up to 3.75 million metric tons of
phosphorus flowing into coastal waters every year. Even such huge
amounts could be dissolved in the open ocean, but most of the
pollution stays in shallow coastal waters where it causes massive
algal blooms and depletes oxygen levels, harming marine life near
the shores.

Although the world still possesses an estimated 240,000 square
kilometers (93,000 sq. mi.) of mangrove swamps—coastal
forests that serve as breeding grounds and nurseries for many
commercially important fish and shell-fish species—this
represents only about half the original amount. Clear-cutting for
timber, fuelwood and wood chips; conversion to fish and shellfish
ponds; and expansion of urban areas and croplands have claimed
millions of hectares globally. For example, of the
Philippine's original mangrove area—estimated at
500,000 to1 million hectares—only100,000 hectares remain:
80 to 90 percent are gone.

Some 600,000 square kilometers (230,000 sq. milt) of coral
reefs survive in the world's tropical seas. Unfortunately,
these species-rich ecosystems are suffering widespread decline.
Clive Wilkinson, a coral reef specialist working at the
Australian Institute of Marine Science, estimates that fully 10
percent of the world's reefs have already been degraded
"beyond recognition." Thirty percent are in critical
condition and will be lost completely in 10 to 20 years, while
another 30 percent are threatened in and will be lost in 20 to 40
years. Only 30 percent, located away from human development or
otherwise too remote to be exploited, are in stable
condition.

Throughout much of the world, coastal zones are overdeveloped,
overcrowded and overexploited. Already nearly two-thirds of the
world's population—some 3.6 billion people—live
along coasts or within 150 kilometers (100 ml.) of one. Within
three decades, 75 percent, or 6.4 billion, will reside in coastal
areas—nearly a billion more people than the current global
population.

In the United States, 54 percent of all Americans live in 772
coastal counties adjacent to marine coasts or the Great Lakes.
Between 1960 and 1990, coastal population density increased from
275 to nearly 400 people per square kilometer. By 2025, nearly 75
percent of all Americans will live in coastal counties, with
population density doubling in areas such as southern California
and Florida.

Similarly, nearly 780 million of China's 1.2 billion
people—almost 67 percent—live in 14 southeast and
coastal provinces and two coastal municipalities, Shanghai and
Tianjin. Along much of China's coastline, population
densities average more than 600 per square kilometer. In Shanghai
they exceed 2,000 per square kilometer. During the past few
years, as many as 100 million Chinese have moved from poorer
provinces in central and western regions to coastal areas in
search of better economic opportunities. More ominously,
population growth is expected to accelerate in the nation's
14 newly created economic free zones and five special economic
zones, all of them coastal.

Water: Distribution Woes

Nearly 75 percent of the world's fresh water is locked in
glaciers and icecaps, with virtually all the rest underground.
Only about 0.01 percent of the world's total water is easily
available for human use. Even this tiny amount would be
suff~cient to meet all the world's needs if it were
distributed evenly. However, the world is divided into water
"haves" and "have note." In the Middle East,
north Asia, northwestern Mexico, most of Africa, much of the
western United States, parts of Chile and Argentina and nearly
all of Australia, people need more water than can be sustainably
supplied.

As the world's human population increases, the amount of
water per person decreases. The United Nations Educational,
Scientific and Cultural Organization (UNESCO) estimates that the
amount of fresh water available per person has shrunk from more
than 33,000 cubic meters (1.2 million cu. ft.) per year in 1850
to only 8,500 cubic meters (300,000 cu. ft.) today. Of course,
this is a crude, general figure. But because of population growth
alone, water demand in more than half the world's countries
by 2000 is likely to be twice what it was as recently as
1971.

Already some 2 billion people in 80 countries must live with
water constraints for all or part of the year. By the end of the
1990s, Egypt will have only two-thirds as much water for each of
its inhabitants as it has today, and Kenya only half as much. By
then, six of East Africa's seven nations and all five nations
on the south rim of the Mediterranean will face severe shortages.
In 1990, 20 nations suffered water scarcity, with less than 1,000
cubic meters (35,000 cu. ft.) of water per person, according to a
study by Population Action International. Another eight
experienced occasional water stress. The 28 nations represent 335
million people. By 2025, some 48 nations will suffer shortages,
involving some 3 billion residents, according to the study.

China—although not listed as water short because of the
heavy amount of rain that falls in its southern region—has,
nevertheless, exceeded its sustainable water resources. According
to Qu Geping, China's Environment Minister, the country can
supply water sustainably to only 650 million people, not the
current population of 1.2 billion. In other words, China is
supporting twice as many people as its water resources can
reasonably sustain without drawing down groundwater supplies and
overusing surface waters.

Fossil Fuels: Energy Breakdown

Human society runs on energy, principally fossil fuels such as
oil, gas and coal. These three account for 90 percent of global
commercial energy production. Nuclear power, hydro-electricity
and other sustainable resources provide the rest.

The industrialized nations, with less than a quarter of the
world's people, burn about 70 percent of all fossil fuels.
The United States alone consumes about a quarter of the
world's commercial energy, and the former Soviet Union about
a fifth. In terms of per capita consumption patterns, Canada
burns more fuel than any other nation—in 1987 the
equivalent of 9 metric tons of oil per person—followed by
Norway at 8.9 metric tons of oil per person and the United States
at 7.3. By contrast, developing nations on average use the
equivalent of only about half a metric ton of oil per person
yearly.

Known oil reserves should meet current levels of consumption
for another 41 years, up from an estimated 31 years in 1970
thanks to better energy efficiency and conservation measures,
along with new oil fields brought into production. Natural gas
reserves should meet current demand for 60 more years, up from 38
years in 1970. Coal reserves should be good for another 200
years.

But our addiction to fossil fuels has resulted in chronic,
sometimes catastrophic, pollution of the atmosphere, in some
cases far beyond what natural systems or man-made structures can
tolerate. A noxious atmospheric cocktail of chemical pollutants
is primarily responsible for the death and decline of thousands
of hectares of European forests. Acid rain— caused by a
combination of nitrogen and sulfur dioxides released from
fossil-fuel combustion—has eaten away at priceless
monuments and buildings throughout Europe and North America,
causing billions of dollars in damage.  

Urban air contains a hazardous mix of pollutants everything
from sulfur dioxide and reactive hydrocarbons to heavy metals and
organic compounds. Smog alerts are now commonplace in many cities
with heavy traffic. In Mexico City, for example, smog levels
exceeded World Health Organization standards on all but 11 days
in 1991. Breathing the city's air is said to be as damaging
as smoking two packs of cigarettes a day, and half the city's
children are born with enough lead in their blood to hinder their
development.

The only way to stretch fossil fuel reserves and reduce
pollution levels is to conserve energy and use it much more
efficiently than we do now. Some progress has been made, but the
benefits of energy conservation have been realized in only a few
industrialized countries.

Recent history has shown what can happen. In the decade
following the first oil shock, per capita energy consumption fell
by 5 percent in the member states of the Organization for
Economic Cooperation and Development (OECD)—consisting of
the industrialized countries of Western Europe and North America,
plus Japan, Australia and New Zealand—while their per
capita gross domestic product grew by a third.

Buildings in the OECD countries use a quarter less energy now
than they did before 1973, while the energy efficiency of
industry has improved by a third. Worldwide, cars now get 25
percent more kilometers per gallon than they did in 1973. In all,
increased efficiency since 1973 has saved the industrialized
nations $250 billion in energy costs.

Even more savings could be realized through concerted efforts
to conserve energy and improve efficiency. Three relatively
simple, cost effective measures could be introduced immediately:
1) making compact fluorescent lamps generally available in homes
and offices; 2) tightening up building codes to require better
insulation against cold and heat; and 3) requiring lean-burn
engines, which get up to 80 kilometers per gallon (50 mpg), in
all new compact cars. These three "technical fixes"
could save billions of dollars in energy costs.

Policy: Building a Future

The main population issues—urbanization, rapid growth
and uneven distribution— when linked with issues of
environmental decline, pose multiple sets of problems for
policymakers. The very nature of these interrelated problems
makes them virtually impossible to deal with in balkanized
bureaucracies accustomed to managing only one aspect of any
problem. Population and resource issues require integrated,
strategic management, an approach few countries are in a position
to implement.

Sustainable-management strategies, designed to ensure that
resources are not destroyed by overexploitation, are complicated
to initiate because they require the cooperation of ministries or
departments often at odds over personnel, budgets and political
clout. Most governments lack institutional mechanisms that ensure
a close working relationship among competing ministries.
Consequently, most sustainable-development initiatives never get
beyond words on paper. "We talk about integrated resource
management, but we don't do it," admits one Indian
official in Delhi. "Our ministries are like fiefdoms, they
seldom cooperate on anything."

Fragmented authority yields fragmented policies. Big
development ministries—such as industry and commerce,
transportation, agriculture, fisheries and forestry—rarely
cooperate in solving population and resource problems. Piecemeal
solutions dominate, and common resources continue to deteriorate.
 

The world's population and resource problems offer plenty
of scope for timely and incisive policy interventions that
promise big returns for a relatively small investment. As little
as $17 billion a year could provide contraceptives to every woman
who wants them, permitting families throughout the globe to
reduce births voluntarily. This approach might produce the same
or better results than would government-set population targets,
according to one study. Moreover, population specialists
recognize that educating girls and women provides a higher rate
of return than most other investments. "In fact, it may well
be the single most influential investment that can be made in the
developing world," says Larry Summers, a former World Bank
economist.

But time is at a premium. The decision period for responding
to the crises posed by rapidly growing populations, increased
consumption levels and shrinking resources will be confined, for
the most part, to the next two decades. If human society does not
succeed in checking population growth, the future will bring
widespread social and economic dislocations as resource bases
collapse. Unemployment and poverty will increase, and migrations
from poorer to richer nations will bring Third World stresses to
the developed world.

Copyright 1994 by the National Wildlife Federation.
Reprinted with permission from International Wildlife
magazine's September/October 1994 issue.