Chapter
7, section 2
People
and Their Environment
Key
Terms
acid rain
smog
eutrophication
bycatch
As
the people of the United States and Canada look to the future, they confront
many challenges. Over the past two centuries, the United States and Canada have
created mighty economies. Sometimes, however, people have lost sight of the
importance of preserving resources as well as utilizing them. As a result, they
have harmed the land that gives them both life and livelihoods. Some of this
harm comes in the form of human-made pollutants. At other times, overuse of
natural resources is the problem.
HUMAN/ENVIRONMENT
INTERACTION
As
the tide of chemicals born of the Industrial Age has arisen to engulf our
environment, a drastic change has come about.... For the first time in the
history of the world, every human being is now subject to contact with
dangerous chemicals, from the moment of conception until death.
Acid
Rain
One
kind of pollution that affects plants and fish is acid rain—precipitation that carries abnormally high amounts of
acidic material. This acidic material is created when the chemicals emitted by
cars, factories, and power plants react with the water vapor in the air. For
example, fumes belching out of industrial smokestacks may carry high amounts of
sulfur dioxide—which becomes sulfuric acid— while car exhaust includes nitrogen
oxide— which becomes nitric acid. Scientists estimate that about 60 percent of
the nitrogen oxide in the whole region comes from cars and trucks.
Sulfuric
acid and nitric acid are found in acid rain. As acid rain falls to the ground,
it corrodes stone and metal buildings and bridges, damages crops, and pollutes
the soil.
Acid
rain also takes a terrible toll on the waters of the region. Fish and other
marine life cannot live in waters with high acid levels.
Acid rain is held responsible
for the deaths of at least 15,000 Canadian lakes, as well as 8 percent of the
lakes found in New York’s Adirondack Mountains. An additional 150,000 North
American lakes have been damaged by this form of pollution.
Because the emissions that help
create acid rain are carried by the wind, the source of these chemicals often
is far from where the rain finally falls. This results in emissions from United
States industries accounting for much of Canada’s acid rain. Nearly one-half of
the acid rain that falls on eastern Canada comes from emissions in the
midwestern and northeastern sections of the United States.
As a result of acid rain
crossing country borders, these 2 nations have spent the last 15 years working
together to solve this problem. In the 1980s, they worked to identify causes of
acid rain. Then, in 1991, the governments signed a pact to reduce by half the
1980 level of emissions that
contribute to acid rain by the end of the century.
Smog
The
nitrogen oxides that help create acid rain also are a major ingredient in smog, a haze caused by the sun’s
interaction with exhaust gases. Smog kills plants and also harms the human
population, burning people’s eyes and irritating their throats and lungs.
The
California city of Los Angeles is plagued by smog. In Los Angeles, the 8
million cars and trucks on the road produce between 70 and 80 percent of all
smog-causing emissions. Smog is measured daily in Los Angeles. On days when the
smog’s yellow haze is too thick, smog alerts are issued. During these alerts
people with respiratory diseases are asked to stay inside, and everyone is told
to drive only if necessary.
To
deal with this problem of smog, many governments have passed laws regulating
car emissions. California and several other states are requiring that, by 1998,
2 percent of all cars sold in the state create no emissions. By the year 2003,
that figure jumps to 10 percent. In response, Chrysler recently introduced a
”zero-emission” minivan that runs on electricity instead of nitrogen-producing
gasoline. In addition a Massachusetts company has a solar-powered car on the
drawing board. It is estimated that by the turn of the century
200,000
cars that run on alternate fuel sources will be on California’s roads,
Pollution
and the Great Lakes
Water
systems in the United States and Canada are polluted not only by acid rain but
also by sewage and industrial and agricultural wastes dumped by humans into the
water supplies. The Great Lakes have been polluted in this way. Once considered
an inexhaustible resource, these waters have been used as dumping sites. This
problem grew as industries and cities began to spring up along the shores and
dump their wastes into the lakes. In 1976, one writer described one of the
sources of Lake Erie’s pollution like this:
One can stand, for example, at the top of a
evelandskyscraperand see the Cuyahoga River :nn’mgout into Em as a thick,
chocolate-brown tram carrying the washings of a dozen steel works.
Surrounding industries also expose the ’eat Lakes to
the effects of thermal pollution, ised by the release of heated industrial iter
into the cooler lake water. Runoff from ms using chemical fertilizers and
pesticides i o damages life in the lakes.
All this pollution has had a profound effect rn the
marine life of the Great Lakes. In recent uars the amount of fish provided by
Great I ike fisheries has decreased by millions of pounds. Pollution has had a
particularly se\\ re impact on some fish species such as the valuable lake
herring.
Another result of all this pollution is the speedup
of eutrophication. Eutrophication is the process in which a lake, or other body of water, becomes rich
in dissolved nutrients. These nutrients nurish many small plants, especially
algae. In i treme cases, these masses of plants—in their owing, dying, and
decomposing—can use up all the oxygen in a body of water, leaving none for the
fish. The algae also can choke the lake, eventually turning it first into a
marsh, and finally into dry land. Normally, eutrophication takes thousands of
years. The minerals spilled into the waters as humans pollute, however, speeds
up this process. Scientists fear that this
pollution is causing eutrophication to occur in sections of Lake Erie.
Today
the governments of Canada and the United States have passed legislation
designed to decrease the pollution in the Great Lakes region and other waters.
In addition, the United States offers financial aid to state and local
governments to encourage construction of sewage treatment and water treatment
facilities. These facilities work to remove contaminated particles before the
waste reaches water sources. As a result of the efforts of federal, state or
provincial, and local governments, some progress has been made in bringing the
waters of the Great Lakes and other bodies of water to their natural state.
HUMAN/ENVIRONMENT
INTERACTION
Overuse of Resources
As pioneers struggled to settle
this region, they slashed, hacked, and burned their way through the forests
that stood before them. At the same time, fishing fleets from many European
nations discovered the wealth of marine life in the North American coastal
waters and began filling their holds with fish. These activities, begun and
often continued without regard to conservation, have seriously depleted two resources on which the economies
of the United States and Canada depend.
Logging
Wood and wood products are
important economic contributors to this region. The United States leads all
other nations, producing 15 percent of the world’s wood. Canada, to which
lumber represents an even more important export, supplies more than 5 percent.
All this lumber production requires more than 1.5 million workers and 45,000
manufacturing facilities. These huge numbers indicate the importance of the
lumber industry to employment in the region.
In the United States, logging
companies are allowed to harvest logs from public lands. The United States
Forest Service is charged with monitoring this harvesting. The Forest Service’s
job is to balance timber harvests with other uses of public forestland,
including recreation and preservation of wildlife habitats. Some conservation
leaders claim that the Forest Service is putting lumber profits above other
concerns, because its budget is partly based on money earned from lumber sales.
Another concern is the Forest
Service’s approval of clearcutting. When a forest is clearcut, all trees are
cut down. In addition, roads must be built into the forests so that the lumber
can be brought out. The Forest Service has constructed 365,000 miles (587,000
km) of roads for logging companies—more than eight times the lengths of roads
comprising the Federal Interstate Highway System. Conservationists argue that
the combination of road-building and clearcutting destroys the natural
ecosystem of the area,
Clearcutting also threatens the
remaining old-growth forests of the Pacific Northwest. A common definition for
old-growth forests is forests ”containing at least 8 big trees per acre and exceeding
300 years in age or measuring more than 40 inches (102 cm) in diameter at
breast height.” Between 1986 and 1988, more than 100,000 acres (40/500 ha) of
old-growth forest were cleared each year. If this rate continues, all
old-growth forests will disappear from the Pacific Northwest by the end of the
20th century.
This clearcutting of old-growth
trees also endangers the wildlife of a region. For example, the northern
spotted owl, whose home is the old-growth forests of the Pacific Northwest, was
placed on the endangered species list in 1990. Experts say that to save the
bird from extinction, logging in this area will have to be cut back
drastically. This has pitted the fate of a species against the jobs of a
region. Clearcutting deprives humans of other benefits of old growth as well.
For example, a potential treatment for cancer was discovered using the bark of
the yew tree. Yew trees thrive in old-growth forests and were traditionally
viewed by loggers as trash trees, burned during the clearcutting process. Some
scientists worry about what valuable discoveries will be gone with the lost
old-growth forests.
One
alternative to clearcutting is called sustainable forestry. When this method is
used, certain trees in a forest are targeted for harvesting while other trees
are left untouched. In addition, trees harvested in this way can be taken from
the forest by mule or horse, which means extensive roads would not have to be
built. Sustainable forestry would protect the area’s natural ecosystem and preserve
old growth.
The
confrontation between the lumber industry and conservationists is far from
over. In response to the concern about lost lumber jobs, one environmentalist
said:
The
question in the Pacific Northwest is not whether the logging of old growth
should stop, but when. The supply of ancient trees is limited.
Fishing
The
abundance of fish in the oceans along the Atlantic Coast was in part
responsible for original European settlement of this region. As early as 1497,
explorer John Cabot reported bountiful fishing in the Grand Banks area. The
Grand Banks consists of a 139,000-square-mile (360010-sq.-km) area off the
southeast coast of Newfoundland. Fishing fleets from England, France, and Spain
came to reap the fishing site’s economic benefits. Immigrants, mostly from
Ireland, England, and France, settled the coasts of Newfoundland and became
actively involved in catching and preparing fish for regional and foreign
markets.
By
the mid-1900s, fishing by ships from many nations had depleted the fish
population. As a result, Canada imposed a fishery conservation zone covering a
200-nauticalinile (370-km) band around its coast. This zone, however, was not
wide enough to include the Grand Banks. Fishing off the eastern coast,
especially by foreign fleets, has continued even as the number of fish decline.
In
1992, the Canadian government, concerned about dwindling populations of cod in
the waters, lowered cod-fishing quotas by 35
percent
and announced the temporary closing of Newfoundland’s east coast cod shery.
These actions caused the largest layoff in Canadian history, putting 20,000
people out of work. Newfoundlanders, so reliant on fishing, are still trying to
recover from these economic blows.
A
combination of pollution and overfishing also has damaged the fishing industry
in the United States. In one recent seven-year period, the total United States
catch declined by more than 25 percent.
Waste
in the fishing industry also is partly responsible for the depletion of fish
populations. High-tech trawlers sweep the oceans for fish, often catching
unwanted fish species, marine mammals, and birds. This dead bycatch, as it is called, is simply
tossed overboard. Scientists estimate that more than 10 percent of the fish
caught worldwide are bycatch, thrown away by commercial fishers. It is believed
this amount easily equals the amount of fish caught in all United States waters
every year. Conservationists urge increased government funding to develop shing
gear that will cut down on the amount of bycatch netted by shing ships.
SECTION
REVIEW
Checking for Understanding
1. Define
acid rain, smog, eutrophication, bycatch.
2.
Locating Places
Where are this region’s old-growth forests located?
3. Human/Environment Interaction
How has pollution affected the Great Lakes?
4.
Human/Environment Interaction
What caused the largest layoff in Canadian history?
Critical
Thinking
5.
Drawing Conclusions Why has acid rain made it necessary for the
governments of the United States and Canada to work together?