Human Population Growth

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Unit 3 Chapter 5.3, 6.1, 6.3

• Human Population Growth
• Humans and the Biosphere
• Biodiversity

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5.3 Human Population Growth

• Human population tends to increase dramatically
  over time.
• Exponential Human pop. growthis mainly due to
• Nutrition
• Sanitation
• Medicine
• Health care

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World Population Growth

• Growth rate reached peak about 1962-1963
• The human population is still growing in size but
  the growth rate is slowing down.

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Patterns of Human Population Growth
Demography- examines characteristics of human
populations and attempts to explain how those
populations will change over time. Birth rates,
death rates, and the age structure of a
population will help predict why some countries
have high growth rates while other countries grow
more slowly.
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6.1 Humans and the Biosphere
Humans affect regional and global environments
through agriculture, development, and industry in
ways that have an impact on the quality of
Earths natural resources, including soil, water,
and atmosphere. Agriculture- a dependable supply
of food can be stored for later use. Enabled
humans to gather and settle in cities and
towns. Monoculture- enables efficient sowing,
tending, and harvesting of crops using machines.
(example, soy beans)
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Development As many more people choose to live
in cities and suburbs, these areas produces more
and more wastes and they can affect air, water,
and soil resources. Industrial Growth
Industrial growth due to building of homes,
clothes, electronics, require a lot of energy to
produce and to power. Many industries produce
waste directly into air, water, and soil.
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Sustainable Development Ecosystem goods and
services (clean air and water) are often not
free. If there is no natural resource towns must
spend money to mechanically or chemically treat
the water. Renewable resources- can be replaced
or produced by a healthy ecosystem (a tree that
is cut down, then a new one is replanted. Nonrene
wable resources- cannot be replenished within a
reasonable amount of time. (fossil fuels like
coal, oil, and natural gas) Sustainable
development provides for human needs while
preserving the ecosystems that produce natural
resources.
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Approved April 19, 2011, the Cape Wind Project
will build 130 wind turbines that will supply the
cape and the islands with ¾ of its energy needs.
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6.3 Biodiversity- is the total of all genetically
based variation in all organisms in the
biosphere. Ecosystem diversity- the variety of
habitats, communities, and ecological processes
in the biosphere. Species diversity- the number
of different species in the biosphere or in a
given area.
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Genetic Diversity- the sum of all the different
forms of genetic information carried by a
particular species, or by all organisms on
Earth. Why is the geneticdiversity of a
species important to its survival?
Biodiversity Video 827
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Benefits of biodiversity
Wild species are the original sources of many
medicines. Many drugs come from plants and other
living things. Genetic biodiversity is important
in agriculture. The genes of wild plants can be
used to breed or genetically engineer new plants
that can become very useful crops. The number
and variety of certain species (keystone species)
maintain an ecosystems stability, productivity
and value to humans. Example Honey bee video
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Threats to Biodiversity

• Altered habitats for development or farming
• Hunting and demand for wildlife (exotic pets)
• Introduced species (invasive species)
• Pollution DDT, pesticides, acid rain, excess
  carbon dioxide
• Climate change

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Conserving Biodiversity Protecting individual
species Scientists trap and selectively breed to
maximize genetic diversity, then reintroduce into
the environment (panda bear) Preserving
Habitats and Ecosystems Sanctuaries, parks,
protected areas all preserve habitats. Considerin
g local interests Incentives for buying solar
panels or carbon credits for companies.