Transcript Climate - Images

The Water
Cycle
• The total amount of the
earth’s water doesn’t change
nor does it stay on one
place. It is constantly
moving from the oceans, to
the air, to the ground, & back
to the oceans.
• There are 3 main
phases:
1. evaporation
2. condensation
3. precipitation
• Evap – this occurs
when the sun’s heat
turns liquid water
into a water vapor
(called humidity) &
moves into the air
• The vapor changes back into a liquid,
which is called condensation. Tiny
droplets of water come together to form
clouds.
• The water falls from the clouds as
precipitation.
• The water soaks into the ground & collects
into streams & rivers & move back to the
oceans.
Types of Water
1. Freshwater – Only
about 3% of the
earth’s water is
freshwater. Of
that, almost 2% is
frozen in ice &
glaciers.
- Lakes, rivers, &
groundwater make
up the rest of the
freshwater.
2. Salt Water – Ocean
water makes up about
97% of the earth’s
water.
- There are 5 oceans.
1.Pacific – the largest. It
covers about 63 million
- is about 31 million sq. miles & is
sq. miles, making it
the most traveled ocean. Its name
larger than all the land
comes from Atlas of Greek
mass combined. It’s
mythology.
name comes from a
3. Indian – 3rd largest; Asia is to the
Latin word, which
means “peaceful sea”
north & Africa to the west.
& was named by
4. Arctic – smallest ocean; lies almost
Magellan.
entirely around the Arctic Circle.
2. Atlantic – 2nd largest;
5. Southern – named in 2000, it
completely surrounds Antarctica.
• Weather – the constant change in the air
during a short period of time. It changes from
day to day.
• Climate – the usual pattern of weather events
in an area over a long period of time.
Types of Climates
1. Tropical – This climate These are almost always
warm & moist.
gets its name from the
- There are 2 types of
tropics, which are
Tropical Climates
located b/w the Tropic of
1. The tropical rain
Cancer & the Tropic of
Capricorn.
forest – wet most of the
year.
2. The tropical
savanna climate – has 2
seasons, one wet, one
dry.
2. Mid-Latitude
Climate – Most of
the world’s people
live in this region.
There is a good bit
of variety.
Warm air comes from the
Tropics, & cool air comes
from the polar regions.
Temps. change from season
to season.
- There are 4 types of MLCs:
1. Marine West Coast Climate
2. Mediterranean Climate
3. Humid Continental Climate
4. Humid Subtropical Climate
3. High-Latitude
Climates – are cold
everywhere
- 3 Types:
1. Subarctic Climate –
very few people live
here. Huge
evergreen forests
called taiga are here.
2. Tundra Climate –
tundra, vast treeless
plains, are here. This
area is harsh & dry, &
the lower layers stay
frozen all the time.
3.
Ice Cap Climate – huge
sheets of polar ice ; no
vegetation here, except
funguslike plants & moss
that grows on rocks
4. Dry Climates – These
receive little or no
rainfall. Temps are
extremely hot during
the day & cold at
night.
- 2 Types of Dry:
1. Desert Climatereceive less than 10”
of rain per year.
(By comparison, North
Alabama receives
about 57.5” per yr.)
2. Steppe Climate- Many
deserts are surrounded
by partly dry grasslands
& prairies known as
steppes.
The Wind & Ocean Currents Effects
on Climate
• Winds follow patterns,
& they move north,
south, east, & west.
• El Nino – forms when
cold winds from the east
are weak. W/o these
winds, the Pacific grows
warmer than usual.
More water evaporates
& more clouds form.
Some areas get lots of
rain, while others get
very little.
- are believed to
occur about every 3
years.
• La Nina – the exact opposite of El Nino.
- Winds from the east become very
strong, cooling the Pacific. Heavy clouds
form in the Pacific.
• Ocean Currents – Moving streams of
water, called currents, carry warm & cold
water through the world’s oceans.
- These currents effect the climate of
land areas.
The Impact of
People on Climate
• It causes the
greenhouse effect.
• The burning of coal, oil &
natural gas as energy
sources releases certain
gases into the air.
• The buildup of these
gases can be dangerous.
•The gases prevent the
warm air from rising &
escaping into the
atmosphere.
• As a result, the overall
temp. of the earth will
increase.
• Some scientists predict terrible results
from this global warming, but others
argue that the world isn’t warming.
The Earth’s Atmosphere
• The atmosphere, a thin
layer of gases, is made
up mostly of nitrogen &
oxygen.
• The condition of the
atmosphere varies from
day to day, season to
season.
• Once the sunlight is absorbed, it is changed into
heat energy.
• When the sunlight is changed into heat, the
Earth’s surface & atmosphere warm up. The
measurement of heat is called temperature.
• Human actions
have
environmental
effects on the
atmosphere.
• The ozone layer is
a region in the
atmosphere that
blocks ultraviolet
radiation from the
Sun.
• UV rays can cause
many problems
(EX: Skin cancer)
Skin Cancer
• B/C of pollution,
there is now a hole
in the ozone.
• The hole is located
over Antarctica &
was 1st noticed in
the 1970’s.
• Many types of pollution
have been the cause of the
ozone hole.
• ChloroFluroCarbons
(CFCs) are a major
contributor to the ozone
depletion.
• CFCs are found in
refrigeration systems, air
conditioners, and aerosols. • Another problem is
nitrogen oxides,
which are found in
aircraft &
automobiles.
The Biosphere is
the part of the
Earth where all
the living
organisms live.
Rainforests are
being destroyed
every day.
A large reason is
b/c of the logging
companies that
deforest, or clear
the land to
harvest trees.
The worst destruction is in
Brazil, Indonesia, SE Asia,
South America & Mexico
50% of all plants & animals
on Earth live in rainforests.
• Desertification is
the process which
turns productive
land into desert
land b/c of poor
land management.
• This occurs on
land that borders
deserts.
• The deserts are
growing.
Examples: Desertification in China
Causes of desertification:
1. Overgrazing of animals
2. Destruction of vegetation
3. Accidental burning of vegetation
4. Incorrect irrigation practices
(Water is lost off the land instead of
soaking into the soil to provide
moisture for the plant.)
The
Lithosphere
is the solid part
of the Earth
consisting of
the crust &
outer mantle
The Lithosphere
• One problem is land
degradation, the
natural reduction of
the Earth surface
caused by erosion.
Another is
salinization, when
large amounts of salt
get into the soil due to
improper irrigation.
Causes of Land Degradation:
1. Hurricanes
2. Earthquakes
3. Areas subject to
insect invasion
4. Drylands
5. Intensive grazing
6. Flooding
The Hydrosphere
is the watery layer of the Earth’s surface
Pesticides
•
•
are chemicals used
to kill pests, esp.
insects
Sometimes they
make their way into
river systems &
groundwater.
They also affect our
drinking water.
Positive Things We’re Doing for the
Environment:
1. The Clean Air Act:
• Federal law passed in 1970
• Designed to make sure all Americans have
air that is safe to breathe
• Requires the US EPA (Environmental
Protection Agency) to set up nat’l
standards to protect against pollutants
• State gov’ts must create clean-up plans to
meet the health standards of the EPA (EX:
clean-up of smog)
Positive Things We’re Doing for the
Environment (con’t):
2. Prevent forest fires – the burning of fires
causes pollution and reduces forest land
• Restocking fish –
replenishes loss of fish
3. Water purification
4. Awareness