CHANGING THE PHYSICAL ENVIRONMENT
Unit
Overview
To
meet their needs and to improve their lives, the people of the Eastern
Hemisphere have adapted to their physical environment in a wide variety of
ways. Sometimes, however, this simply
not enough to accommodate the world’s growing population. As a result, people have tried to change
their surroundings. As you will see in
this unit, this has had both intended and unintended consequences.
Why
People Change their Physical Environment
The
physical environment of the Eastern Hemisphere influenced human activity. People found food, built shelters, and wore
clothes based on the climate, landforms, and waterways surrounding them. At first, they simply adapted to the
conditions where they lived so that they could meet their needs and make life
better. As time went on, however,
advancements in science and technology eventually led humans not only to adapt to
their environment but to change, or modify,
it.
Farming
and herding were some of the first steps that people took to control the world
around them. The construction of roads,
cities, dams, and pipelines followed.
The intended consequences, or goals, of these
modifications were also to meet needs and to make life better. However, changes to the environment also have
resulted in unintended consequences. These are effects that no one planned for or
thought would happen. Farming, herding,
highways, dams, urbanization, and pipelines have had both intended and
unintended consequences.
Farming
Farming is one of the most common ways to
modify the physical environment. Across
the Eastern Hemisphere, farmers plow the soil, fertilize it, and plant
seeds. They often look for ways to find
more land to farm. If the land is too
dry, people change the paths of waterways and create irrigation systems.
Sometimes more land is made available for planting by cutting steps in steep
hillsides. This is called terrace farming. The picture below shows a terrace farm located
in Vietnam. In other regions, farmers clear forests and
grasslands by the slash-and-burn
method. They cut down plants and trees,
burn them, and plant crops. All of these
human activities change the physical environment.
Farming
has both intended and unintended consequences.
The goal of this human activity is to grow healthy plants and to meet
the challenge of feeding an increasing world population. Although farmers often meet these goals, agriculture
does have unplanned side effects. For
example, clearing trees and brush for farmland has caused deforestation in some areas.
Deforestation occurs when large numbers of trees are lost and new ones
are not planted to take their place.
Wild animals lose their habitats, and some become endangered. Scientists
claim that deforestation contributes to global warming and climate change. A farmer often use pesticides and fertilizers
to increase the size of the harvest and to prevent insects from destroying
it. When rain washes these same
chemicals into creeks and streams, animals, fish, and humans may be harmed
unintentionally.
Herding
In
some parts of the Eastern Hemisphere, people raise animals, or livestock, to help meet their needs for
food and transportation. They include
goats, sheep, cows, horses, kangaroos, yaks, and many other animals. Many of
these are important to the food supply because they provide meat and dairy
products, such as milk, yogurt, butter, and cheese. Along with this intended
consequence, herding has also resulted in unintended consequences. To survive, livestock eat plants and
grasses. For this reason, herders remove
trees and larger plants to encourage the growth of grasslands. Like farming, this practice can lead to
deforestation. For example, in the early
1900s, forests covered over one-third of the land in the African nation of Ethiopia. Today, only a little over one-tenth of the
country’s area consists of forests. This
is because herders have expanded the grassland to support their cattle. The lack of forests has destroyed the
habitats of many animals and has put some, like the Ethiopian wolf, on the
endangered list. It has also contributed
to the erosion of the soil and climate change.
Photo Courtesy of Justin Clements: CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=414957
Highways
Another
way in which humans modify their physical environment to fit their needs is by
building roads, highways, bridges, and tunnels.
Roads and highways make it possible for the people of the Eastern
Hemisphere to get from one place to another in their own cars and trucks. This is an intended consequence of highway
construction. At the same time, it makes
it convenient for everyone to drive more.
This increases the need for bigger and more complicated road networks. A number of unintended consequences occur as
a result. For example, to provide better
roads, governments must find the money to pay for them. This usually means taking money from something
else that is equally important or increasing taxes. More running engines mean more gases and
particulates that are harmful to people and their physical environment. The ever-increasing number of cars on the
road also leads to traffic jams like this one in Beijing, China.
In
earlier times, road construction simply went around mountains and hills. Modern technology, however, has given us
heavy equipment that can move millions of tons of soil and rock. Look at the two images below. A rugged mountain range, known as the Alps, stands along the border of
Switzerland and Italy. The highway that
winds through the mountains has long been an important link between the cities
of Lucerne, Switzerland and Milan, Italy.
It has also been called one of the most dangerous roads in the
world.
Today,
a thirty-five mile railroad tunnel stretches under the mountains. Completed in 2016, the Saint Gotthard Pass Tunnel permits high-speed trains to carry
passengers and products along a safer, faster route. It is also expected to reduce air pollution
over time. This is because high-speed
trains create less pollution than cars and trucks. These are the tunnel’s
intended consequences. The government of
Switzerland also planned the project carefully to avoid negative side
effects. Because this was such a large
undertaking, this was not entirely possible.
Surrounding communities experienced air, water, and noise pollution
during and after construction.
Dams
and Rivers
The
people of the Eastern Hemisphere sometimes try to fulfill their needs for food,
transportation, and energy by building dams.
A dam is a barrier that holds
back water. The build-up of water behind
the barrier is called the reservoir. Dams have several intended consequences. The
right amount of water from the reservoir can be released at the right
time. This helps to prevent floods and
enables farmers to irrigate their crops in dry climates. Flowing water can also be used to turn
turbines that create hydroelectric power. Hydroelectric power generates over one-fifth
of the world’s electricity. Egypt’s Aswan High Dam is an example of a dam
that provides hydroelectric power, irrigation, and protection from floods. You can see this dam and its reservoir, Lake Nasser, in the image below.
Although
the Aswan High Dam has been beneficial, it has also had some negative side
effects. The creation of Lake Nasser put
the homes of 90,000 Egyptians under water.
Relocating was a difficult process and took time. The waters of Lake
Nasser also threatened to destroy one of Egypt’s greatest tourist attractions,
the Temple of Abu Simbel. Moving the temple and its sixty-five foot
statues cost the Egyptian government millions of dollars. For centuries, the farmers living along the
Nile River had relied on the annual floods to bring a fresh coat of top soil
for their fields. After the dam was
built, they had to rely on fertilizers, which were expensive and poisonous to
humans and animals. The video listed below shows other examples of projects
that have changed the flow of rivers. In
China, this means constructing an artificial river that will carry water from
the south to the drier lands in the north.
Urbanization
Across
the Eastern Hemisphere, humans have changed the natural landscape by building
cities. They have constructed houses,
apartment buildings, skyscrapers, sidewalks, and miles of roads. People continue to move into cities because
they want to improve their lives. The movement of people to cities is called urbanization. Compared to the
countryside, cities offer more jobs, greater access to education, and more
varieties of entertainment. These are
some of the intended consequences of living in cities.
Photo Courtesy of Tropenmuseum, part of the National
Museum of World Cultures
In
Africa and Asia, many cities are growing at rapid rates. One example is Jakarta, the capital of Indonesia. Since 1970, this city’s population has expanded
from 4,000,000 to 14,000,000. The increase continues to place greater demands
on the region’s physical environment.
This has created unintended consequences for those who live there. More people means more cars and trucks. Therefore, the city’s residents struggle with
traffic jams and air pollution on a daily basis. Providing drinking water for so many people
is another constant challenge. At the
same time, if the city is going to have adequate housing for its population, it
must find more space. Clearing more
land, however, is likely to further damage the region’s ecosystem. The ecosystem
is the plant and animal life that exists in the area. Each native plant and animal contributes
something significant to the ecosystem.
Expanding without careful planning destroys this balance. The videos listed below explain more about
what it is like to live in Jakarta.
Pipelines
To
help meet the need for energy, countries in the Eastern Hemisphere have
modified the physical environment by adding pipelines. Pipelines
consist of a series of pipes and pumps.
They carry oil, natural gas, and other resources underground and
underwater. Pipelines are an important
part of Russia’s oil and natural gas industries. Russia
has large reserves of oil and natural gas, but there is a problem. Much of the supply is located in Siberia. This region of Russia experiences very cold
temperatures for much of the year. It is
also far from the country’s industrial complexes and the areas in which most
people live. Ice and snow make travel by
truck difficult. For this reason, Russia
transports much of its oil and natural gas through pipelines.
Although
this has solved one problem, it has created unintended consequences. Pipelines have had some negative effects on
the physical environment. Heavy
equipment used to put the pipelines in place have destroyed forests and animal
habitats. Because the climate of Siberia
makes it hard to maintain these structures, leaks occur. Oil finds its way into creeks and
streams. This endangers the water supply
of humans and wildlife. The video listed
below explains one herder concerns about the effects of Russia’s oil industry
on Siberia’s physical environment.
Costs
and Benefits
Dams,
highways, and many other projects mentioned in this unit have a very high price
tag. Are they worth the cost? This is a question that each society must
decide for itself. For example, China’s
effort to create an artificial river is called the North-South Water Transfer Project.
Although Chinese leaders believe that this will benefit the country’s
economy in the long run, they have already spent 80 million dollars on its
construction. The entire project is not
scheduled to be finished unit 2050. Will
customers be able to afford the water when it arrives? Like individuals, governments must budget
their money. To spend more money in one
area, funds must be cut from other programs.
If this is not acceptable, countries must borrow money or raise taxes. None of the options are popular.
Time
for a Quick Review
Before
moving on to Quit 6, take a few minutes to review the terms found in Unit
5. Be sure that you can answer the “Can
I” questions listed here with a loud “yes”.
Additional Activities and Resources