Human Demands on
Natural Resources
H
UMANS have needs. These needs
include food, clothing, and shelter. Such needs are met by using or
placing demand on natural resources.
How much demand can our earth’s natural resources meet? Is there a limit to
the earth’s ability to meet the needs of
the human population?
Objectives:
þ
1.
2.
3.
4.
Explain how humans use natural resources.
Describe human population trends.
Identify urban and rural impacts on natural resource use.
Explain the impact of recycling and reusing resources.
Key Terms:
Ñ
basic human needs
biodegradable
birth rate
death rate
human population
life expectancy
migration
recycling
reusing
Human Use of Natural Resources
Humans require natural resources to live and go about life activities. Some natural
resources are renewable; others are nonrenewable. We know that we need to use natural
resources wisely so that supplies will last indefinitely. We don’t want to run out of essential
resources!
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BASIC NEEDS
Basic human needs are the biological needs of humans that must be met for them to
remain in the living condition. Food, clothing, and shelter are often listed as the three basic
human needs. Providing these involves using natural resources.
Food and water provide needed nutrients. Food is typically obtained from plants and animals produced on farms and ranches. Plant food products include grains, vegetables, fruits,
and nuts. Foods from animal sources include meat, milk, and eggs. Producing plants and animals requires soil, water, air, and other natural resources. Modern production uses tractors and
implements that require fuel to plow the land, plant seeds, harvest the crops, and transport,
process, and store the food. Fortunately, today’s farmers use practices that protect the environment and promote sustained agricultural production.
Clothing and shelter make considerable use of products from renewable natural resources,
though some make use of products from nonrenewable natural resources. Clothing is made
from plant and animal products.
Cotton is the most important
plant. Wool and leather are the
most important animal products
used in making clothing. Some
clothing items are made from
nonrenewable minerals and fossil
fuels.
Shelter involves the use of a
great deal of renewable wood,
though minerals in brick, concrete, and other materials are
used. Nonrenewable materials are
used in roofing, plumbing sysFIGURE 1. Supermarkets provide a wide range of food products for
tems, and electrical fixtures.
consumers in the United States. (Courtesy, U.S. Department of Agriculture)
OTHER USES
Humans use natural resources for many activities in life. Often these natural resources are
nonrenewable. Transportation involves vehicles and fossil fuel to operate them. We use transportation in our work and to move products to where they are needed. Education involves natural resources to construct school buildings, provide transportation, provide heating and air
conditioning in the school buildings, and light the classrooms and other facilities. Recreation
uses resources in the building and operation of boats, in the lighting and irrigation of sports
fields, and in hunting and fishing.
Almost every activity in our lives uses natural resources in some way. We depend on many
resources to make our lives comfortable. Look around your home. What products do you have
and use that involve natural resources? How would your life change if you suddenly no longer
had these products?
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Human Population Trends
Human population is the number of people in a given location. Besides worldwide, we
often count human population by towns and cities, states, and nations. Human population has
been increasing and continues to increase in many locations. The increase is sometimes called
a population explosion.
WORLDWIDE AND UNITED STATES
Current worldwide population is 6.5 billion people. Population is increasing at a rapid rate
of 1.2 percent a year. Projections are that the earth’s population will reach 9.4 billion by 2050.
It took from the beginning of time until 1804 for the earth’s population to reach 1 billion!
However, only 12 years were required for the human population to increase from 5 to 6 billion. Improved nutrition, better health care, and other conditions that promote longer human
life spans are contributing to increased population. However, the birth rate has been declining
in some nations, particularly those said to be developed, such as Sweden, Canada, France, and
Iceland.
Population in the United States is increasing. It is now approximately 300 million, with a
projected population of 420 million by 2050. Among nations, only China and India have
greater populations than the United States. Within the United States, California, Texas, and
New York are ranked at the top, based on population. Illinois is fifth among all states, with a
population of 12.5 million people. Wyoming is fiftieth among all states in population.
Billions
10
9
8
7
6
5
4
3
2
1
0
1550
1600
1650
1700
1750
1800
1850
1900
1950
2000
2050
Years
FIGURE 2. World population trends, 1550 to 2050.
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FURTHER EXPLORATION…
ONLINE CONNECTION: POPClock
A POPClock is a means of continually updating human population. The information presented considers
births and deaths. Use a POPClock to prepare a short report on population increases over a day or a week.
You can access up-to-the-minute population information at:
http://www.census.gov/main/www/popclock.html
HOW CHANGES OCCUR
Population numbers change due to migration of people and natural processes of births and
deaths. Migration is the movement of people from one location to another usually a substantial distance away. People often move to areas where they can find jobs and have higher standards of living. The United States is primarily a nation whose population has migrated seeking
new opportunities. The migration has involved current and previous generations.
Natural increases or decreases in population are due to birth and death rates. The average
number of births per 1,000 people each year is the birth rate. Likewise, the average number
of deaths per 1,000 people each year is the death rate. The death rate is also known as the
mortality rate. The birth rate is 15.0 per year in the United States, while it is 9.13 in Italy and
51.0 in Somalia. The death rate is 9.0 per year in the United States, while it is 6.9 in Australia
and 22.0 in Afghanistan. The net gain in rate is determined by subtracting the death rate from
the birth rate. In the United States, the rate of gain is 6.0 (birth rate of 15.0 minus death rate of
9.0).
A major factor in death rate is life expectancy. The number of years a newborn baby may be
expected to live is life expectancy. In the United States, life expectancy is 75.5 years, which
represents an increase of 28.5
years over life expectancy in the
year 1900. Better health care,
improved nutrition, and other
life-sustaining advances have
increased life expectancy. Life
expectancy in other nations varies,
with it being 80.1 in Sweden and
39.3 in Malawi. (Something to
think about is why there is such a
great difference in life expectancy
between Sweden and Malawi, an
African nation.)
FIGURE 3. Improved health care has increased life expectancy.
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Urban and Rural Impacts
Population shifts are often based on opportunities for jobs, cultural benefits, and other reasons. New technologies have changed the nature of work, particularly in agriculture. In the
1800s, most people lived on farms in the United States. Farming was a way of life. As new
methods of agricultural production emerged in the late 1800s and the 1900s, less labor was
required on farms. People were free to go into off-farm industrial and commercial jobs.
Changes in agricultural and industrial opportunities resulted in strong migration patterns
from rural to urban areas. Rural citizens saw fewer opportunities for jobs and for satisfactory
levels of living. They began moving to towns and cities in search of new opportunities. This
migration resulted in rural areas experiencing declining populations and in cities seeing rapid
growth in the United States and other nations.
Masses of people have become
concentrated in large cities. New
York City and Los Angeles are the
largest cities in the United States.
Many other cities are also quite
large, including Chicago and St.
Louis. (Tokyo is the largest city in
the world, with about 35 million
people.) As people become more
concentrated, new problems associated with maintaining a quality
of life emerge.
Cities with large populations
require large amounts of water,
FIGURE 4. Waterfront view of Chicago from Olive Park.
energy, and waste disposal facili-
FURTHER EXPLORATION…
ONLINE CONNECTION: What’s in a Cell Phone?
Can the contents of a cell phone be recycled? Cell phone users discard their telephones after an average use time of 18 months. Several hazardous substances are found in cell telephones. If not recycled,
these can enter the environment. Investigate the contents of cell telephones and prepare a short report on
your findings. (Particularly note if mercury, cadmium, lead, and Galium arsenide are present and investigate the hazards of these substances in the environment. Be sure also to include other substances in your
report.)
Begin your investigation by searching for “cell phones” at the following Web sites:
http://www.worldwatch.org
http://www.informinc.org/
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ties. In the United States, the average daily per person amount of solid waste created is 4.4
pounds. The per person amount of wastewater is nearly 100 gallons a day. Disposing of the
solid waste and the wastewater requires large, sophisticated waste disposal systems. In addition,
the goal is to promote reconditioning of the wastewater so that it is again available for use.
Differences between rural and urban life are not as great as they were a few decades ago.
Rural areas have many of the same conveniences as urban areas. In fact, some rural areas have
more favorable environments to support human health because of smog-free air and other
conditions. Of course, the major medical centers for providing health care are often in the
larger cities.
Recycling and Reusing
Recycling and reusing are practiced to reduce waste as well as conserve natural resources.
Actually, reusing is a kind of recycling, as is explained later. You will see that both are good
practices to reduce waste and promote the wise use of limited natural resources.
Many products are not readily biodegradable, or subject to rapid decay when placed in a
landfill. These products are made of materials such as glass, plastics, and metals that resist
action by microorganisms present in the soil and other locations. They might remain in landfills for many years. Products made of wood and paper, on the other hand, are relatively biodegradable and will decay in a few years in a landfill. It is best to recycle all materials to the extent
possible.
Proper maintenance of equipment and structures promotes longer life and reduces the need
to replace them or take them out of service. Paying attention to the maintenance of a farm tractor, for example, such as regularly lubricating the engine and servicing the air filter, reduces
wear and keeps the tractor in good condition longer.
RECYCLING
Recycling is either using the material in a product to manufacture another product or
reusing the product. The kinds of materials most widely recycled are paper, iron and other
metals, plastics, and glass. Current estimates are that 42 percent of all paper is recycled, as are
55 percent of all aluminum cans and 40 percent of all plastic beverage bottles. Recycling saves
energy while helping sustain nonrenewable natural resources. It reduces the amount of material that goes into landfills as waste.
Recycling procedures vary with the kind of material. Most materials must be sorted for uniformity. Different kinds of metals must be separated, such as copper from aluminum. Different colors of glass must also be separated before being melted and manufactured into new
products. Recycling paper saves trees; and as we know, trees help keep air quality high and
lower the temperature in the summer on the earth’s surface.
Many cities have recycling centers or programs for waste materials. In some cases, a recycler
will pick up the materials at curbside. In other cases, the waste materials must be taken to a
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central collection facility and sorted. Sometimes, a fee is paid for the materials being recycled,
such as aluminum cans.
REUSING
Reusing is a kind of recycling that does not require remanufacturing to gain a useful product. Returnable bottles must be sterilized before reuse, but no additional manufacturing is
required. Paper boxes, milk distribution crates, and wooden pallets on which products are
shipped are three examples of reusable items. A simple reuse is to take a grocery bag back to
the store and pack groceries in it again.
Summary:
2
Humans require resources to live, prosper, and enjoy life. Some of these resources
are used to meet the basic human needs of food, clothing, and shelter. Other
resources are used to carry out daily activities, such as transportation, education, and
recreation. Resources should always be used wisely to assure that supplies will last
indefinitely.
Human population is increasing at a rate of 1.2 percent each year. Today, 6.5 billion
people live on the earth. Some 300 million live in the United States. Changes in
population result from migration and from birth and death rates. Life expectancy
has also increased markedly in the United States. Shifts of population from rural to
urban areas are reflected in migration. Greater numbers of people are concentrating
in large cities and suburban areas surrounding the cities. Large numbers concentrated in small areas result in considerable solid waste and wastewater.
Recycling can be used to reduce demand on natural resources. Paper, iron and
other metals, plastics, and glass are most frequently recycled. Recycling a product
often involves remanufacturing, whereas reusing a product does not.
Checking Your Knowledge:
´
1. What are the three basic human needs? Briefly explain each.
2. What is human population?
3. What factors influence changes in population numbers? Briefly explain each.
4. What has been occurring in population shifts between rural and urban areas?
5. What is recycling? Why is it important?
6. What is the meaning of biodegradable? Give examples of materials that are biodegradable and materials that are not biodegradable.
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Expanding Your Knowledge:
L
Use print media and/or the Internet to read and learn about the meaning and
importance of population control. Prepare a brief report.
Web Links:
:
Chicago Recycling Coalition
http://www.chicagorecycling.org/
Conserve Chicago Together—City of Chicago Streets and Sanitation
http://egov.cityofchicago.org/
EPA Site on Municipal Solid Waste Recycling
http://www.epa.gov/epaoswer/non-hw/muncpl/recyle.htm
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