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

About This Presentation
Title:

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

Description:

... freshwater supply threatens habitat and health. Water pollution ... CONCEPT The impact of a growing human population ... Environmental Protection Agency ... – PowerPoint PPT presentation

Number of Views:383
Avg rating:3.0/5.0
Slides: 34
Provided by: McDoug240
Category:

less

Transcript and Presenter's Notes

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
Earths human population continues to grow.
  • Earths human carrying capacity is unknown.
  • It has changed over time.
  • Todays human population of more than 6 billion
    has exceeded earlier predictions
  • Some limit must exist

3
  • Technology has helped to increase Earths
    carrying capacity.
  • gas-powered farm equipment
  • medical advancements
  • In 1940 more than 40 infants died for every 1000
    births
  • In 2002 only 7 infants died for every 1000 births

4
The growing human population exerts pressure on
Earths natural resources.
  • Nonrenewable resources are used faster than they
    form.
  • coal
  • Oil
  • The growing use of limited resources will lead to
    energy crisis in decades ahead unless
    technologies are developed to use other forms of
    energy.

5
  • 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.

6
Effective management of Earths resources will
help meet the needs of the future.
  • Earths resources must be used responsibly.
  • Careless use of resources makes them unavailable
    to future generations.
  • Easter Island isan example ofirresponsibleresou
    rce use.

7
  • 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

8
  • Several factors affect the size of the ecological
    footprint.
  • amount and efficiency of resource use
  • amount and toxicity of waste produced

9
KEY CONCEPT Fossil fuel emissions affect the
biosphere.
10
Pollutants accumulate in the air.
  • 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 (microscopic bits of dust,
    metal and unburned fuel produced by industrial
    processes) and ground-level ozone

11
  • 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

12
Air pollution is changing Earths biosphere.
  • The levels of atmospheric carbon dioxide rise and
    fall over time.
  • High levels of carbon dioxide are typical of
    Earths warmer periods.

13
  • The same way that greenhouse glass creates an
    environment for plants to grow, the chemical
    composition of Earths atmosphere plays an
    important role in maintaining an environment that
    is suitable for life.
  • Greenhouse gases Act as insulators and slow the
    loss of heat
  • Water Vapor
  • Carbon Dioxide
  • Methane
  • Greenhouse effect occurs when carbon dioxide,
    water and methane molecules absorb energy
    reradiated by Earths surface and slow the release
    of this energy from Earths atmosphere.

14
  • Global warming refers to the trend of increasing
    global temperatures.
  • Scientist can infer that the changes in
    temperature are the result of increased levels of
    greenhouse gases such as carbon dioxide, water
    and methane.
  • Ecological disasters, such as increased flooding,
    stronger tropical storms and the loss of
    biodiversity, are just a few threats that may be
    caused by global warming

15
KEY CONCEPT Pollution of Earths freshwater
supply threatens habitat and health.
16
Water pollution affects ecosystems.
  • Pollution can put entire freshwater ecosystems at
    risk.
  • - Runoff from farms and cities
  • Disrupts the chemical balance
  • Stimulation of plant an algae overgrowth can
    drastically lower the levels of dissolved oxygen.
  • Fish populations die off
  • Detritivores are not able to break down waste

17
  • Indicator species provide a sign of an
    ecosystems health.
  • amphibians
  • top predators
  • Aquatic indicator species show
  • the direct effects of pollution.

18
Biomagnification causes accumulation of toxins in
the food chain.
  • 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.
  • EX Mercury, Polychlorinated biphenyls

19
KEY CONCEPT The impact of a growing human
population threatens biodiversity.
20
Preserving biodiversity is important to the
future of the biosphere.
  • The loss of biodiversity has long-term effects.
  • loss of medical and technological advances
  • extinction of species
  • loss of ecosystem stability
  • When a species goes extinct
  • it is gone forever.
  • A loss of biodiversity makes it more difficult
    for an ecosystem to handle future change.

21
Loss of habitat eliminates species.
  • Habitat fragmentation prevents an organism from
    accessing its entire home range.
  • occurs when a barrier forms within the habitat
  • often caused by human development
  • To try and fix this problem, some states are
    building overpasses or underpasses so that
    wildlife can avoid busy roadways.

22
  • Habitat corridors are a solution to the problem.
  • corridors can be road overpasses or underpasses
  • allow species to move between different areas of
    habitat

23
Introduced species can disrupt stable
relationships in an ecosystem.
  • An introduced species is one that is brought to
    an ecosystem by humans.
  • accidental
  • purposeful
  • Invasive speciescan have anenvironmentaland
    economicimpact.

24
  • Invasive species often push out native species.
  • Burmese python (Florida Everglades)
  • Originally from the tropical jungles of
    Southeastern Asia

25
  • Invasive species often push out native species.
  • mice (Australia)

26
  • Invasive species often push out native species.
  • kudzu (southeastern United States)

27
KEY CONCEPT Conservation methods can help
protect and restore ecosystems.
28
Sustainable development manages resources for
present and future generations.
  • Sustainable development meets needs without
    hurting future generations.
  • resources meet current needs
  • resources will still be available for future use

29
  • The timber industry has started to adopt
    sustainable practices.
  • Global fisheries have adopted several sustainable
    practices.
  • rotation of catches
  • fishing gear review
  • harvest reduction
  • fishing bans

30
Conservation practices focus on a few species but
benefit entire ecosystems.
  • The Endangered Species Act works to protect
    individual species from extinction.
  • A listed species is often called an umbrella
    species.
  • Protection of that species means that other
    species will also be protected.
  • the habitat in which the species lives must be
    protected
  • other species are protected because they share
    the ecosystem

31
Protecting Earths resources helps protect our
future.
  • The Environmental Protection Agency (EPA) was
    created in 1970.
  • The EPA develops policies and regulations to
    protect the environment.
  • Legislation helps to protect the environment and
    endangered species.
  • Clean Air Act
  • Clean Water Act
  • Endangered Species Act

32
  • The National Park Service helps manage public
    lands.
  • The park system includes over 390 areas, covering
    84 million acres.

33
  • There are several ways that people can help
    protect the environment.
  • control population growth
  • develop sustainable technology and practices
  • protect and maintain ecosystems
Write a Comment
User Comments (0)
About PowerShow.com