KEY CONCEPT As the human population grows, the demand for Earth - PowerPoint PPT Presentation

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KEY CONCEPT As the human population grows, the demand for Earth

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Title: PowerPoint Presentation Author: McDougal Littell Last modified by: Jennifer McQuade Created Date: 9/14/2006 4:17:10 PM Document presentation format – PowerPoint PPT presentation

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Title: KEY CONCEPT As the human population grows, the demand for Earth


1
KEY CONCEPT As the human population grows, the
demand for Earths resources increases.
2
Objectives
  • Summarize the current state and effects of human
    population growth
  • Explain the importance of effective resource
    management

3
Vocabulary
  • Nonrenewable resource
  • Renewable resource
  • Ecological footprint

4
Earths human population continues to grow.
  • Earths human carrying capacity is unknown.

5
  • Technology has helped to increase Earths
    carrying capacity.
  • gas-powered farm equipment
  • medical advancements

6
The growing human population exerts pressure on
Earths natural resources.
  • Nonrenewable resources are used faster than they
    form.
  • coal
  • oil

7
  • Renewable resources cannot be used up or can
    replenish themselves over time.
  • wind
  • water
  • sunlight
  • Growing use of nonrenewable resources may lead to
    a crisis.
  • Resources must be properly managed.

8
  • An ecological footprint is the amount of land
    needed to support a person.
  • The land must produce and maintain enough
  • food and water
  • shelter
  • energy
  • waste

9
  • Several factors affect the size of the ecological
    footprint.
  • amount and efficiency of resource use
  • amount and toxicity of waste produced

10
Give 3 examples of how technology has influenced
human population growth
11
What is the difference between renewable and
nonrenewable resources
  • Renewable Resources
  • Nonrenewable Resources

12
What factors can limit the growth of the human
population?
13
16.2 Air Quality
KEY CONCEPT Fossil fuel emissions affect the
biosphere.
14
Objective
16.2 Air Quality
  • Describe the sources, types, and effects of
    pollution
  • Explain how air pollution contributes to acid rain

15
Vocabulary
  • Pollution
  • Smog
  • Particulate
  • Acid rain
  • Greenhouse effect
  • Global warming

16
Pollutants accumulate in the air.
16.2 Air Quality
  • Pollution is any undesirable factor added to the
    air, water, or soil.
  • Smog is one type of air pollution.
  • sunlight interacts with pollutants in the air
  • pollutants produced by fossil fuel emissions
  • made of particulates and ground-level ozone

17
16.2 Air Quality
  • Smog can be harmful to human health.
  • Acid rain is caused by fossil fuel emissions.
  • produced when pollutants in the water cycle cause
    rain pH to drop
  • can lower the pH of a lake or stream
  • can harm trees

18
Air pollution is changing Earths biosphere.
16.2 Air Quality
  • The levels of atmospheric carbon dioxide rise and
    fall over time.
  • High levels of carbon dioxide are typical of
    Earths warmer periods.

19
16.2 Air Quality
  • The greenhouse effect slows the release of energy
    from Earths atmosphere.
  • sunlight penetrates Earths atmosphere
  • energy is absorbed and reradiated as heat
  • greenhouse gases absorb longer wavelengths
  • Greenhousegas moleculesrereleaseinfraredradiat
    ion

20
16.2 Air Quality
  • Global warming refers to the trend of increasing
    global temperatures.

North Pole
21
Name and describe 2 ways in which pollution
affects ecosystems
16.2 Air Quality
22
How does the greenhouse effect keep Earth warm?
16.2 Air Quality
23
Explain how a build-up of CO2 in the atmosphere
could increase Earths global temperature.
16.2 Air Quality
24
Greenhouse gasses are found close to earths
surface and high above in the atmosphere. Name 2
important functions of greenhouse gasses at
Earths surface.
16.2 Air Quality
25
Ocean producers such as phytoplankton are an
important part of food webs, but they require a
specific temperature range to survive. How might
increased water temperature affect these ocean
food webs?
16.2 Air Quality
26
16.3 Water Quality
KEY CONCEPT Pollution of Earths freshwater
supply threatens habitat and health.
27
Objectives
16.3 Water Quality
  • Describe how water pollution affects ecosystems
  • Explain how biomagnification causes accumulation
    of toxins in food chains

28
Vocabulary
16.3 Water Quality
  • Indicator species
  • biomagnification

29
Biomagnification causes accumulation of toxins in
the food chain.
16.3 Water Quality
  • Pollutants can move up the food chain.
  • predators eat contaminated prey
  • pollution accumulates at each stage of the food
    chain
  • Top consumers, including humans, are most
    affected.

30
2 Types of Pollutants that undergo
Biomagnification are PCBs and DDT
16.3 Water Quality
  • Polychlorinated biphenyls (PCBs) were widely used
    as coolant fluids
  • PCBs can negatively impact growth and development
    within the egg, causing
  • Genetic mutations
  • Deformities
  • Death

31
DDT was made available for use as an agricultural
insecticide after WWII
16.3 Water Quality
  • In 1962, Silent Spring by American biologist
    Rachel Carson was published.
  • The book suggested that DDT and other pesticides
    may cause cancer and that their agricultural use
    was a threat to wildlife, particularly birds.
  • Its publication was one of the signature events
    in the birth of the environmental movement, and
    resulted in a large public outcry that eventually
    led to DDT being banned for agricultural use in
    the US in 1972.
  • The US ban on DDT is cited by scientists as a
    major factor in the comeback of the bald eagle,
    and the peregrine falcon from near-extinction in
    the contiguous US

32
How do PCBs affect bird populations through
biomagnification?
16.3 Water Quality
33
Would a buffalo or a mountain lion be more
affected by biomagnification? Why?
16.3 Water Quality
34
How does the biomagnification pyramid compare
with the energy pyramid?
16.3 Water Quality
35
16.4 Threats to biodiversity
KEY CONCEPT The impact of a growing human
population threatens biodiversity.
36
Objectives
16.4 Threats to biodiversity
  • Assess the consequences of loss of biodiversity
  • Explain how loss of habitat and introduced
    species affect ecosystems and biodiversity

37
Vocabulary
16.4 Threats to biodiversity
  • Habitat fragmentation
  • Introduced species

38
Preserving biodiversity is important to the
future of the biosphere.
16.4 Threats to biodiversity
  • The loss of biodiversity has long-term effects.
  • loss of medical and technological advances
  • extinction of species
  • loss of ecosystem stability

39
Loss of habitat eliminates species.
16.4 Threats to biodiversity
  • Habitat fragmentation prevents an organism from
    accessing its entire home range.
  • occurs when a barrier forms within the habitat
  • often caused by human development

40
  • Habitat corridors are a solution to the problem.
  • corridors can be road overpasses or underpasses
  • allow species to move between different areas of
    habitat

41
Introduced species can disrupt stable
relationships in an ecosystem.
16.4 Threats to biodiversity
  • An introduced species is one that is brought to
    an ecosystem by humans.
  • accidental
  • purposeful
  • Invasive speciescan have anenvironmentaland
    economicimpact.

42
Invasive species often push out native species.
16.4 Threats to biodiversity
  • kudzu (southeastern United States)
  • Burmese python (Florida Everglades) mice
    (Australia)

43
List reasons that biodiversity is important to
humans
16.4 Threats to biodiversity
44
How does habitat fragmentation affect migrating
bird populations?
16.4 Threats to biodiversity
45
What types of damage can introduced species cause?
16.4 Threats to biodiversity
46
How could continued fragmentation reduce
biodiversity?
16.4 Threats to biodiversity
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