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Biology
Chapter
6
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6-2 Renewable and
Nonrenewable Resources
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6-2 Renewable and Nonrenewable
Resources
Classifying Resources
How are environmental resources
classified?
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6-2 Renewable and Nonrenewable
Resources
Classifying Resources
Classifying Resources
Environmental goods and services may
be classified as either renewable or
nonrenewable.
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6-2 Renewable and Nonrenewable
Resources
Classifying Resources
• Renewable Resources – can regenerate if they are alive,
or can be replenished by biochemical cycles if they are
nonliving
• Example: tree, water, air, solar
• Nonrenewable Resources – cannot be replenished by
natural processes
• Once these fuels are depleted they are gone forever
• Example: coal, oil, natural gas
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6-2 Renewable and Nonrenewable
Resources
Sustainable Development
What effects do human activities have on
natural resources?
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6-2 Renewable and Nonrenewable
Resources
Sustainable Development
Human activities can affect the quality
and supply of renewable resources such
as land, forests, fisheries, air, and fresh
water.
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6-2 Renewable and Nonrenewable
Resources
Sustainable Development
Sustainable Development
• Sustainable Development – a way of using natural
resources without depleting them and causing long-term
environmental harm
• If managed properly, soil is a renewable resource
• Soil Erosion – the wearing away of surface soil by
water and wind
• Plowing the land removes the roots that hold the soil
in place, and therefore increases the rate of erosion
• Desertification – process by which productive areas
are turned into deserts
• Caused by farming, overgrazing, drought
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6-2 Renewable and Nonrenewable
Resources
Land Resources
• A Variety of sustainable-development practices can
prevent problems such as soil erosion and desertification
• Contour Plowing – fields are plowed across the slope
of the land to reduce erosion
• Leaving stems and roots of the previous year’s crop in
place to help hold the soil
• Planting a field with rye rather than leaving it
unprotected from erosion
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6-2 Renewable and Nonrenewable
Resources
Forest Resources
Forest Resources
• Earth’s forests are an important resource for the products
they provide and for the ecological functions they perform
• Provide wood for products and fuel
• Remove CO2 and produce oxygen
• Store nutrients
• Provide habitats and food for organisms
• Moderate climate
• Limit soil erosion
• Protect freshwater supplies
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6-2 Renewable and Nonrenewable
Resources
Forest Resources
• Whether a forest can be considered a renewable
resource depends partly on the type of forest
• Temperate forests of the Northeast are renewable
because they have been logged and have grown back
naturally
• Old-growth forests, such as those in Alaska and the
Pacific Northwest, are nonrenewable because it takes
centuries to produce them
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6-2 Renewable and Nonrenewable
Resources
Forest Resources
• Deforestation
• Erosion can wash away nutrients in the topsoil
• Loss of forests, or deforestation, has several
effects:
• Grazing or plowing can permanently change local
soils which prevents the regrowth of trees
• Forest Management
• Mature trees can be harvested selectively to promote
the growth of younger trees and preserve the forest
ecosystem
• Tree geneticists are breeding new, faster-growing
trees that produce high-quality wood
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6-2 Renewable and Nonrenewable
Resources
Fishery Resources
Fishery Resources
• Fishes and other animals that live in water are a valuable
source of food
• Overfishing
• Harvesting fish faster than they can reproduce
• Has greatly reduced the amount of fish in parts of the
world’s oceans
• Fisheries seemed to be a renewable resource, but
overfishing has limited that resource
• U.S. National Fisheries Service has issued guidelines
that specify how many fish, and of what size, can be
caught.
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6-2 Renewable and Nonrenewable
Resources
Air Resources
Air Resources
• The condition of the air affects people’s health
• Smog – a mixture of chemicals that occurs as a graybrown haze in the atmosphere
• Is due to automobile exhausts and industrial
emissions
• Considered a pollutant because it threatens people’s
health
• Pollutant – a harmful material that can enter the
biosphere through the land, air, or water
• The burning of fossil fuels can release pollutants that
cause smog and other problems in the atmosphere
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6-2 Renewable and Nonrenewable
Resources
Air Resources
• Strict automobile emissions standards and clean-air
regulations have improved air quality in many cities, but
air pollution is still a problem
• Acid Precipitation – nitrogen and sulfur compounds in the
atmosphere combine with water vapor and fall to the
Earth in the form of rain, snow, sleet or fog
• Acid precipitation kills plants by damaging their leaves
and interferes with plant growth
• Acid precipitation may dissolve and releases toxic
elements such as mercury from the soil, freeing the
element to enter other portions of the biosphere
• Also changes the pH of lakes, streams and ponds
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6-2 Renewable and Nonrenewable
Resources
Air Resources
Formation of Acid Rain
Chemical Transformation
Condensation
Nitric acid
Sulfuric acid
Emissions to Atmosphere
Dry Fallout
Nitrogen oxides
Sulfur dioxide
Industry
Transportation
Precipitation
Particulates Acid rain, fog,
Gases
snow, and mist
Ore
smelting
Power
generation
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6-2 Renewable and Nonrenewable
Resources
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6-2 Renewable and Nonrenewable
Resources
Freshwater Resources
Freshwater Resources
• Americans use billions of liters of fresh water daily for
everything from drinking and washing to watering crops
and making steel
• Although water is a renewable resource, the total supply
of fresh water is limited and is threatened by pollution
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6-2 Renewable and Nonrenewable
Resources
•
Freshwater Resources
Sources of freshwater pollution include:
•
improperly discarded chemicals that enter streams
and rivers.
•
wastes discarded on land that seep through soil and
enter underground water supplies.
•
domestic sewage containing compounds that
encourage growth of algae and bacteria.
•
sewage containing microorganisms that spread
disease.
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6-2 Renewable and Nonrenewable
Resources
Freshwater Resources
• Sustainable Use of Water
• One way to ensure the sustainable use of water is to
protect the natural systems involved in the water cycle
that help purify water
• Example: wetlands, forests, rock layers
• Also by conserving water in:
• Home
• Industry
• Agriculture
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6-2
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6-2
Which of the following is a nonrenewable
resource?
a. trees
b. grasses used by grazing animals
c. oxygen in the air
d. fossil fuels
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6-2
Which of the following is a sustainable-use
strategy that can help prevent desertification?
a. contour plowing
b. protecting wetlands
c. aquaculture
d. selective harvesting of trees
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6-2
The advantage of sustainable development is
that it
a. provides for human needs without depleting
natural resources.
b. produces additional fossil fuels.
c. protects wildlife from hunters and other
threats.
d. is a natural process that regulates itself.
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6-2
A mixture of chemicals that occurs as a haze in
the atmosphere is known as
a. smog.
b. acid rain.
c. particulates.
d. fog.
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6-2
Plowing the land removes the roots that hold the
soil in place and increases the rate of
a. pollution.
b. soil erosion.
c. deforestation.
d. soil formation.
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END OF SECTION
The Fate of Spilled Oil
• According to a well-known saying that oil and water don’t
mix, it might be expected that spilled oil would float around
until it was washed ashore
• A single gallon of oil can spread enough to cover up to
four acres of water
• As soon as the oil is spilled in a marine environment,
many changes begin to take place
• Within days, 25% of the oil is lost through evaporation
• The remaining oil sinks to the bottom of the ocean
• It adheres to almost all objects that it encounters
• After 3 months only 15% of the original oil remains
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• If a substantial oil spill occurred close to shore rather
than at sea, the effects would be different because there
would not be sufficient time available for the process
described above to affect the total amount of oil involved
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Short-Term Effects of Oil Spills
• Short-term effects receive the most publicity because
they are immediately obvious
1. Reduction of Light Transmission
• Light intensity 2m below an oil slick can be reduced
by 90%
• Reduces the rate of photosynthesis so plants and
protists die
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2. Reduction in Dissolved Oxygen
• Oil film blocks rate of oxygen uptake by water
• DO is lower in oil contaminated water
3. Damage of Marine Birds
• Birds covered with oil can drown
• Oil causes bird feathers to mat together and reduces
the birds ability to fly and float in water
• Feathers lose their insulating ability
• Birds die because of exposure to cold weather or
inability to get food
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4. Toxic Effects to Marine Environment
• Oil contains benzene, toluene, xylene, which are toxic
to plants and animals
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Long-Term Effects of Oil Spills
• Long-term effects are not as apparent as the short-term
effects because they require more extensive research
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Methods of Oil Spill Clean-Up
• Booms or Barriers
• Contain oil slick
• Makes it easier to skim the oil off the surface
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• Skimmers
• Used to remove oil from the surface of the water
• They are attached to ships or may be hand-held along
shore
• Skimming works best in calm waters
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• Sorbents
• Materials used to soak up oil spills
• Example: straw, powered clay, sawdust, chopped corn
cobs, pine bark
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• Chemical Dispersants, Detergents, and Solvents
• Used to degrade the oil
• Unfortunately most of these chemicals are toxic to
animals
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• Flames
• Used to burn the oil
• The black smoke contains toxic components
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Bioremediation
• The oil spill cleanup methods listed above only recover
10-30% of the spilled oil
• The most environmentally safe prospect for the cleanup of
oil spills is the use of oil-degrading microbes
• Bioremediation – the use of naturally occurring
microorganisms that have been genetically engineered
and that can be used to degrade petroleum products
• A microorganism called petrophiles are spread across an
oil spill and they degrade the oil and convert it into food
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• The microorganisms may be mixed with nutrients such as
nitrogen, phosphorus, and cottonseed protein that not
only enhance the microbial growth, but also absorb the oil
and provide a matrix for the microorganisms to continue
to degrade the absorbed oil
• The treated oil slick begins to break up and turn into a
yellowish substance that eventually diminishes in size
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Case Study – The Exxon Valdez
• In the spring of 1989, the largest oil spill in U.S. history
occurred when an oil tanker named the Exxon Valdez hit
a reef in Prince William Sound off the coast of Alaska
• More than 10 million gallons of crude oil spilled
• The oil slick covered more than 1,000 miles of coastline
• Caused an estimated 5 billion dollars in environmental
damages
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• The Exxon Valdez disaster killed more wildlife than any
other environmental disaster in our nation’s history
• 250,000 seabirds died
• 2,800 sea otters died
• 300 harbor seals died
• 250 bald eagles died
• 22 killer whales died
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6-3 Biodiversity
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6-3 Biodiversity
The Value of Biodiversity
The Value of Biodiversity
• Biodiversity – the variety of life in an area
• A rain forest has a greater amount of biodiversity than a
cornfield
• The simplest and most common measure of biodiversity is
the number of species that live in a certain area
• Areas nearer the equator have a greater amount of
biodiversity
• Large islands tend to have a higher biodiversity than
smaller islands
• Biodiversity brings stability to an ecosystem
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6-3 Biodiversity
The Value of Biodiversity
•
Species diversity – the number of different species in the
biosphere.
•
Genetic diversity – the sum total of all the different forms
of genetic information carried by all organisms living on
Earth today.
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6-3 Biodiversity
The Value of Biodiversity
Why is biodiversity important?
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6-3 Biodiversity
The Value of Biodiversity
Biodiversity is one of Earth's greatest natural
resources.
• Species of many kinds have provided us with:
• Food
• Medicines
• Industrial products
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6-3 Biodiversity
Threats to Biodiversity
What are the current threats to
biodiversity?
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6-3 Biodiversity
Threats to Biodiversity
Threats to Biodiversity
Human activity can reduce biodiversity by:
• altering habitats
• hunting species to extinction
• introducing toxic compounds into food
webs
• introducing foreign species to new
environments
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6-3 Biodiversity
Threats to Biodiversity
• Extinction – the disappearance of a species when the last
of its members dies
• Since 1980’s almost 40 species of plants and animals
living in the United States have become extinct
• Although extinction can occur as a result of natural
processes, humans have been responsible for the
extinction of many species
• Threatened Species – when the population of a species
begins declining rapidly
• Endangered Species – when its numbers become so low
that extinction is possible
• As the population of an endangered species declines, the
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species loses genetic diversity
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6-3 Biodiversity
Threats to Biodiversity
Mussels
Fanshell
Catspaw
Ring Pink
Endangered
Endangered
Endangered
Pink Mucket
Little-wing Pearlymussel
Orange-foot Pimpleback
Rough Pigtoe
Endangered
Endangered
Endangered
Endangered
Fat Pocketbook
Cumberland Bean Mussel
Northern Riffleshell
Endangered
Endangered
Endangered
Clubshell
Endangered
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6-3 Biodiversity
Threats to Biodiversity
Fish
Blackside Dace
Threatened
Palezone Shiner
Endangered
Pallid Sturgeon
Endangered
Birds
Bald Eagle
Endangered
Red-cockaded Woodpecker
Endangered
Interior Least Tern
Endangered
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6-3 Biodiversity
Threats to Biodiversity
Mammals
Gray Myotis (bat)
Endangered
Indiana Myotis (bat)
Endangered
Virginia Big-eared Bat
Endangered
Insects
American Burying Beetle
Endangered
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6-3 Biodiversity
Threats to Biodiversity
Plants
Price's Potato-bean
Threatened
Cumberland Sandwort
Endangered
Cumberland Rosemary
Threatened
White-haired Goldenrod
Threatened
Short's Goldenrod
Endangered
Virginia Spiraea
Threatened
Running Buffalo Clover
Endangered
Chaffseed
Endangered
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6-3 Biodiversity
Habitat Alteration
Habitat Alteration
• When land is developed, natural habitats may be
destroyed
• Habitat loss is the biggest threat to biodiversity
• With habitats gone, the essentials of life are lost for
species dependent upon these habitats and species
disappear
• Habitat Fragmentation – the separation of wilderness
areas from other wilderness areas
• Presents problems for organisms that need large
areas to gather food
• It can change the climate of the area
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6-3 Biodiversity
Habitat Alteration
• Habitat Degradation – the damage to a habitat by pollution
• Three types of pollution are land, air and water
• The burning of fossil fuels is the greatest source of air
pollution
• The smaller a species habitat is, the more vulnerable the
species is to further disturbance
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6-3 Biodiversity
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6-3 Biodiversity
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6-3 Biodiversity
Introduced Species
Introduced Species
• Another threat to biodiversity comes from plants and
animals that humans transport around the world either
accidentally or intentionally
• Exotic Species – organisms that are not native to a
particular area
• Also called invasive species
• Reproduce rapidly because their new habitat lacks the
predators that would control their population
• Example: zebra mussels, amur honeysuckle, kudzu
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6-3 Biodiversity
Conserving Biodiversity
What is the goal of conservation biology?
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6-3 Biodiversity
Conserving Biodiversity
Conservation Biology
• Conservation – the management of natural resources,
including the preservation of habitats and wildlife
• Conservation efforts focus on protecting entire
ecosystems as well as single species.
• Protecting an ecosystem will ensure that the natural
habitats and the interactions of many different species
are preserved at the same time.
• Many species are in danger due to the actions of
humans, so working with people is an important part of
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conservation biology
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6-3 Biodiversity
Conserving Biodiversity
Strategies for Conservation
• Many conservation efforts are aimed at managing
individual species to keep them from becoming extinct
• U.S. Endangered Species Act – this law made it illegal to
harm any species on the endangered or threatened
species lists
• The law made it illegal for federal agencies to fund any
project that would harm organisms on these lists
• Harm includes changing an ecosystem where
endangered or threatened species live
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6-3 Biodiversity
Conserving Biodiversity
• Conservation biologists focus on protecting whole
communities and whole ecosystems as the best way to
conserve species
• Create more natural preserves
• Only 6% of Earth’s land surface is protected in this
way
• The biggest threat to biodiversity is habitat loss,
preserving land is an effective means of preserving
species
• Reintroduction Programs – release organisms into an
area where their species once lived
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6-3
The type of biodiversity that includes the
inheritance information carried by the Earth’s
organisms is called
a. biological magnification.
b. ecological diversity.
c. genetic diversity.
d. species diversity.
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6-3
Populations of invasive species tend to
a. decrease.
b. increase rapidly.
c. remain constant.
d. increase, then decrease.
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6-3
The wise management of natural resources,
including the preservation of habitats and
wildlife, is known as
a. biodiversity.
b. conservation.
c. habitat alteration.
d. ecosystem diversity.
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6-3
By focusing on protecting specific ecosystems,
biologists hope to preserve
a. global biodiversity.
b. biological magnification.
c. invasive species.
d. habitat fragmentation.
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6-3
The biggest threat to biodiversity is
a. exotic species
b. habitat loss
c. habitat fragmentation
d. pollution
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END OF SECTION
6-4 Charting a Course
for the Future
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6-4 Charting a Course for the Future
Ozone Depletion
What are two types of global change of
concern to biologists?
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6-4 Charting a Course for the Future
6-4 Charting a Course
for the Future
Researchers are gathering data to monitor
and evaluate the effects of human activities
on important systems in the biosphere. Two
of these systems are:
• the ozone layer high in the atmosphere
• the global climate system
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6-4 Charting a Course for the Future
Ozone Depletion
Ozone Depletion
• Ozone Layer – atmospheric layer in which ozone gas is
relatively concentrated
• Between 20 and 50km above Earth’s surface
• The ozone layer absorbs a good deal of harmful
ultraviolet or UV radiation from sunlight before it
reaches Earth’s surface
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Ozone Depletion
• Exposure to UV can:
• Cause cancer
• Damage eyes
• Decrease organisms’ resistance to disease
• Damage plant leaf tissue and phytoplankton in the
oceans
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Ozone Depletion
Early Evidence
• In the 1970’s, scientists discovered a hole in the ozone
layer over Antarctica
• After it was first discovered, the ozone hole grew larger
• A similar ozone hole also appeared over the Arctic
• In 1974, a research team published data showing that
gases called chloroflurocarbons, or CFC’s could damage
the ozone layer
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Ozone Depletion
• CFC’s were once widely used:
• As propellants in aerosol cans
• As coolant in refrigerators, freezers, and air
conditioners
• In the production of plastic foams
• The U.S. and other nations began reducing the use of
CFC’s in 1987, and eventually banned them
• Since the ban the level of CFC’s in the atmosphere had
decreased, indicating that the ban will have positive, longterm effects on the global environment
• Current data predict that the ozone holes should shrink
and disappear within 50 years
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6-4 Charting a Course for the Future
Global Climate Change
Global Climate Change
• All life on Earth depends on climate conditions such as
temperature and rainfall
• Many ecologists are concerned about strong evidence that
climate is changing
• Since the lat 19th century, average temperatures have
risen about 0.6ºC
• Data indicate that since 1980, average temperatures have
risen between 0.2 and 0.3ºC
• Global Warming – the increase in the average temperature
of the biosphere
• One sign of global warming is melting polar ice
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Global Climate Change
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6-4 Charting a Course for the Future
Global Climate Change
Evidence of Global Warming
• The geological record shows that Earth’s climate has
changed repeatedly during its history
• Researchers must determine whether the current warming
trend is part of a larger, natural cycle of climate change, or
whether it is caused by human activity
• A widely accepted hypothesis is that current warming is
related, in part, to human activities that add carbon dioxide
and other greenhouse gases to the atmosphere
• The burning of fossil fuels, along with the cutting and
burning of forests, adds carbon dioxide to the atmosphere
faster than the carbon cycle removes it
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Global Climate Change
• Data show that concentrations of carbon dioxide in the
atmosphere have been rising for 200 years
• As a result, the atmosphere’s natural greenhouse effect is
intensified, causing the atmosphere to retain more heat
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Global Climate Change
Possible Effects of Global Warming
• Most recent computer models suggest that average global
surface temperatures will increase by 1 to 2ºC by the year
2050
• Sea levels may rise enough to flood coastal areas,
affecting coastal ecosystems as well as human
communities
• Parts of North America may experience more droughts
during the summer growing season
• New organisms may be able to live in places where they
once could not
• Other organisms may become threatened or extinct in
areas where they once thrived
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The Value of a Healthy
Biosphere
• Ecosystems provide many goods and services such as….
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6-4 Charting a Course for the Future
The Value of a Healthy
Biosphere
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6-4 Charting a Course for the Future
The Value of a Healthy
Biosphere
• Ecosystems are also a reservoir of organisms that may
one day provide humans with new medicines and new
crops
• People can make wise choices in the use and
conservation of resources
• Avoid using more water than necessary
• Plant trees to replace those that have been cut down
• Recycle and reuse trash and other wastes
• Safely remove hazardous materials
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6-4
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6-4
An increase in the average temperature of the
biosphere is called
a. the greenhouse effect.
b. global warming.
c. ozone depletion.
d. climate control.
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The geological record indicates that Earth’s
climate has
a. remained essentially the same throughout
history.
b. been constant until humans have influenced
the environment.
c. changed dramatically every 150 years.
d. repeatedly changed over its history.
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A possible effect of global warming is
a. extinction of organisms in areas where they
once thrived.
b. an increase in global surface temperature of
20 Celsius degrees.
c. a sharp decrease in the temperature of the
waters off the coast of California.
d. complete elimination of the protective ozone
layer in the atmosphere.
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6-4
Depletion of Earth’s protective ozone layer
results in
a. a decrease in the amount of heat that
reaches the surface.
b. a decrease in the amount of UV radiation
that reaches the surface.
c. an increase in the amount of rainfall.
d. an increase in the amount of UV radiation
that reaches the surface.
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6-4
The most likely cause of ozone depletion is the
a. addition of carbon dioxide to the
atmosphere.
b. increase in UV radiation from the sun.
c. addition of chemicals developed for use in
refrigeration and aerosol cans.
d. increase in the amount of smog produced
by automobiles.
Slide
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END OF SECTION