Download Chapter 22 - Humans and the Environment

Chapter 22 - Humans and the
Environment
22-1 An Interconnected Planet
I. Earths Layers
a. Atmosphere - The mixture of gases surrounding
the Earth.
• Consists of about 78% N, 20.9% O, 1% CO2 and other
trace amounts of other gases.
Climate and Atmosphere
• Ranges from extreme cold
at the poles to tropical
heat at the Equator.
• Temperature decreases as
• climate is an average
weather in a place over
more than 30 years.
• A region's climate is often
described, for example, as
sunny, windy, dry, or
humid.
• weather - the current
daily conditions. These
can change in just a few
hours, whereas climate
changes over a longer
span of time.
b. Hydrosphere
– the liquid water
component of the
Earth.
• Includes the oceans,
seas, lakes, ponds,
rivers and streams.
• Covers about 70% of
the surface of the
Earth
• Home for many plants
and animals.
c. Geosphere
• the solid portion of the earth.
– * the crust and upper mantle of the earth.
– Most of the mantle is liquid.
22-2 Environmental Issues
a. Pollution
– Ozone Thinning
• CFC (chlorofluorocarbons) and other pollutants react with O3 causing a
hole in the ozone layer above Antarctica, brakes down O3 Ozone to O2.
b. Global warming
• Greenhouse effect caused
by three main greenhouse
gases:
– (main gas H2O vapor)
– CO2 from the burning
fossil fuels
– CH4 Methane,
released from swamps
and produced by
cattle.
c. Acid precipitation
– Acid rain comes from sulfur oxides and nitrogen
oxides (gases) which combine with water vapor in
the air and become precipitation with a pH lower
than 7.
II. Land and Water Pollution
a.
•
Biological Magnification – process whereby certain substances
such as pesticides or heavy metals move up the food chain. These
chemicals end up in rivers or lakes from runoff. A cycle of runoff
and evaporation work to concentration the chemicals in the water.
Organisms become contaminated with the chemicals. The levels
of the chemicals increase within the organisms as trophic level
increases. The top of the food chain has the greatest negative
effect.
https://www.youtube.com/watch?v=E5P-UoKLxlA
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Biological magnification wheat
• DDT - (dichlorodiphenyltrichloroethane) is a colorless, crystalline, tasteless
and almost odorless organochloride known for its insecticidal properties.
DDT use is now banned in the USA, but is still used in other nations.
III. Ecosystem Disruption
a. Extinction - the complete disappearance of a species from
the Earth.
• Threatened - the population has gown so small that if something
doesn’t change the species will become extinct.
• Endangered - any species that is in danger of extinction
throughout all or within a significant portion of its range
WWF - Endangered and threatened species.
– Ecosystem Imbalances – Human Resource Use
b. Ecosystem Imbalance
• When a natural or human-caused disturbance disrupts the
natural balance of an ecosystem.
• A disturbance is any change that causes a disruption in the
balance of an ecosystem.
– Natural disturbances are volcanic eruptions, floods, or natural
fires.
– Human-caused disturbances are the introduction of a new
species, logging a forest, pollution, or overhunting of a species.
• After a disturbance occurs, an ecosystem can recover back
to a balanced state. But if an ecosystem has a severe
disturbance or is constantly having new disturbances it may
never recover back to a state of ecological balance.
Human Resource Use
22-3 Environmental Solutions
I. Conservation and Restoration Biology
A. Conservation Biology - is the study of the
species and the ecosystem with the primary to
protect species, their habitats, and the
ecosystem from excessive rates of extinction and
the loss of biotic interactions.
B. Restoration Biology – scientists use their in
depth knowledge of nutrient cycles, energy flow,
and ecosystem species to help a badly damaged
ecosystem recover
II. Species and Habitats
• There are specific species in many different
ecosystems that can be used to determine the
health of the ecosystem. These species are
called bioindicators.
– An example of this for our ecosystem are frog
species. Their skin is highly permeable making
them very susceptible to environmental
contaminants.
Biodiversity Hotspots
• Areas that have a high diversity of species as
well as unique species.
• contain 44% of all vascular plants, 35% of all
species of all four groups of vertebrates.
(animals with a backbone)
• Less than 2% of the globe
– Amazon rain forest
– Great barrier reef
Government and Laws
• There are laws to reduce or limit harmful
pollution. (fines)
• There are laws to protect threatened and
endangered species. (fines)
• International multi-nation forums to address
international and global issues. Global
warming, Ozone depletion.
Tragedy of the commons
• is a term used to describe a situation where
individuals acting independently and
rationally according to their own self-interest
which is contrary to the best interests of the
everyone by depleting some common
resource.
• Example: over fishing the oceans.
Your role
• What can you do????