Download Climates - Hobbs High School

Climate and
Climate Change
So how do weather and
climate differ?
How are they the same?
It’s time for a foldable!
LATITUDE
ELEVATION
TOPOGRAPHY
BODIES of WATER
GLOBAL WIND
VEGETATION
Factors That Affect Climate
Make a vertical fold that
leaves about 1 inch
along one long edge
Make a horizontal fold
down the middle, then
fold again horizontally
into thirds.
Then label it as shown.
Yes, you can borrow the
scissors.
Copy this diagram (and leave an
inch or so for other notes)
Latitude
The most intense heating is
where the sun’s rays strike
most directly, at the
equator. As solar elevation
angle (SEA) decreases, the
sun’s energy is spread over a
larger area and is therefore
less intense, meaning less
heating near the poles!
Latitude (cont.)
POLAR ZONE
TEMPERATE ZONE
TROPICS
TROPICS
TEMPERATE ZONE
POLAR ZONE
Elevation
• Air temperature
decreases with
elevation about 6.5°C
with every 1000
meters.
• The HIGHER the
elevation, the
COLDER the climate.
• Compare Phoenix
and Flagstaff
Topography
• Topographic features such as mountains
affect the amount of precipitation that falls
over an area.
Bodies of Water
• Large bodies of water such as OCEANS
and LAKES affect the temperature of an
area because the water moderates the
temperatures of land areas downwind.
• The more constant temperature of the
water causes the air passing over it to
have less temperature change
throughout a year than air over land.
•So for the same
latitude, a place
downwind from a
large body of water
has warmer winters
and cooler summers
than a more inland
place.
•Compare the
average annual
temperature ranges of
Seattle and Spokane,
WA.
Global Winds
•Atmospheric circulation distributes
heat and moisture around the
globe. Winds constantly move
warm air toward the poles and
cool air toward the equator.
•Areas of low pressure at the
equator and the subpolar
regions have cloudiness and
associated precipitation.
•Areas of high pressure
(subtropical highs) at 30 degrees
north and south latitude are
deserts and dry regions.
Vegetation
• You know that the kind
of vegetation depends
on the climate.
•But did you know that the vegetation can affect
the climate?? Vegetation can affect both the
temperature and the moisture patterns for an area.
• Vegetation influences how much of the
sun’s energy is absorbed and how quickly
it is released.
• Water vapor is
released into the
atmosphere through
TRANSPIRATION from
plants’ leaves. This
influences moisture in
the atmosphere.
Stoma in tomato leaf taken with
scanning electron microscope
(colorized)
Transpiration
• Different kinds of plants transpire
different amounts of water vapor.
• An acre of corn gives off about 3,0004,000 gallons (11,400-15,100 liters) of
water each day, and a large oak tree
can transpire 40,000 gallons (151,000
liters) per year (that’s 110 gallons each
day).
• Some scientific studies have shown that
vegetation releases particles that act as
nucleation sites for cloud formation.
Such clouds could influence precipitation
patterns in a region.
• “Terrestrial vegetation and atmospheric
photochemistry produce large amounts
of fine particles in the atmosphere, thereby
cooling Earth's climate.”
http://www.physorg.com/news/2010-10-results-atmospheric-aerosolproperties-climate.html reporting on research published in Nature,
October 2010
“Next to methane, deciduous plants and trees such
as oak and maple, are known to be the largest
source of hydrocarbons in the atmosphere; an
important factor in climate-change.”
In 2009, scientists found a new, tree-released
hydrocarbon called isoprene that appears to form
aerosols which are an important part of cloud
formation. “ ‘Clouds can retain as well as block
the heat of the sun, so, if we don't understand
what drives the formation of clouds, our
climate-models are bound to be less than
exact’.”
http://www.physorg.com/news169202056.html
21.3 Climate Changes
Natural Processes that Change Climate
Set up your notes for three columns like this:
Natural
Process
Cause
Effect
Volcanic Eruptions
• Puts aerosols
 More solar radiation is
(volcanic ash, dust,
reflected back into
sulfur-based aerosols)
space, so Earth’s
into the troposphere
lower atmosphere
cools for days to years
Ocean Circulation
• Remember you
 Can result in shortlearned about the El
term climate
Niño Southern
fluctuations such as
Oscillation pattern in
increases in
the Pacific.
precipitation or
decreases in
precipitation
Solar Activity
• Cycles in solar
 Warm periods in
North America and
activity, such as the
Europe correspond to
11-year sunspot
the maxima in the
cycle, correspond
sunspot cycle, when
to short-term
the sun is most active
climate changes.
• Solar irradiance
increases by 0.1%
at solar maxima
Earth Motions
• Long term changes Result in ocean
in the locations of
basins opening and
Earth’s tectonic
closing and the
plates
locations of land
masses
More Earth Motions
• There is a 41,000
The smaller the tilt,
year cycle in the tilt
the smaller the
of Earth’s axis of
temperature
2.4 degrees.
differences
between summer
and winter
More Earth Motions
• There is a 100,000 year  Changes in the shape
cycle in how elliptical
of Earth’s orbit result in
Earth’s orbit is, due
different season
mostly to gravitational
lengths.
interactions with Jupiter
and Saturn.
• However, there is
another 100,000 year
cycle, the inclination of
Earth's orbit up and
down relative to its
present orbit.
Even More Earth Motions
Scientists don’t understand yet if either or
both of these cycles is the cause of the
100,000 cycle in ice ages which has
major effects on Earth’s very long-term
climate
The Greenhouse Effect
(Put these notes in the bottom row of your table.)
What is it? The greenhouse effect is a natural
warming of both Earth’s lower atmosphere and
Earth’s surface. The major gases involved are
carbon dioxide and water vapor which are
transparent to incoming solar radiation.
When this energy is absorbed by Earth’s surface and
lower atmosphere, it is changed to infrared radiation.
The IR is then absorbed by these gases as it is
radiated toward space, warming the surface and
lower atmosphere.
Scientists believe that without the
greenhouse effect, it’s unlikely Earth would
be warm enough for complex life to have
developed here.
Human Impacts on Climate
Impact on
Greenhouse Effect
Global Warming is
Climate change
Cause
Effect
Human Impacts on the Greenhouse Effect
Many scientific studies indicate that human
activities for the past 200 years have had
a huge impact on the greenhouse effect.
Much of the carbon dioxide added to the
atmosphere is due to the burning of fossil
fuels, such as petroleum, coal, and natural
gas.
The clearing of forests also contributes to
the increase of CO2 because this gas is
released when vegetation is burned or
when it decays.
Global Warming
Is Global Warming the same thing as the
Greenhouse Effect?
NO! Global warming is the increase of
global temperatures as a result of increases
in carbon dioxide and other greenhouse
gases (such as water vapor and methane) in
the atmosphere.
During the 20th Century, Earth’s average
surface temperature increased about 0.6°C,
and by 2100 scientists predict temperatures
will increase by 1.4°C to 5.8°C.
The Earth has experienced many shifts and
changes in climate over its 4.6 billion year
lifespan due to both the natural causes we
already learned about and catastrophes
such as asteroid impacts and megavolcano
eruptions.
There have been many ‘extinction events’ in
Earth’s history where many forms of life died
off. There have been many ‘ice ages’.
Compared to these events, how could
humans cause much difference to
Earth’s climate?
Human Impact on Climate Change
• Humans have contributed to climate change long
before our modern industrial period (last 200
years), by using fire to clear lands, agricultural
practices, and overgrazing of marginal lands
by domestic animals.
• Since the Industrial Revolution, levels of CO2
have risen markedly.
• What is controversial is whether human activities
are the cause of climate change, and, if so, what
we can do about preventing further change that will
negatively affect our environment and society.
Is There Scientific Consensus on
Global Warming?
• Yes, 97% of climate scientists agree that humans are
causing climate change
• Scientific research includes computer models that
successfully reproduce temperature data, which
means the models are based on a correct
understanding of the physical and chemical
mechanisms involved.
• Statement from 18 science organizations
• American Association for the Advancement of Science
(127,000 members)
• American Chemical Society (160,000 members)
• American Geophysical Union (60,000 members)
• American Physical Society (48,000 members)
What will be the effects
of global warming?
• Warmer surface temperatures increase
evaporation rates increasing the amount of
water vapor in the atmosphere. Water vapor is
an even better greenhouse gas than carbon
dioxide is, magnifying the effect of more CO2.
• Sea ice and ice sheets will melt, reducing
Earth’s albedo (and increasing the absorption of
solar energy at the surface) and raising global
sea levels (leading to coastal flooding and
shoreline erosion).
More effects of global warming
• Changes in weather patterns, such as more
intense heat waves and droughts in some
regions and more intense hurricanes.
• Other predicted effects include: warming of the
oceans leading to coral reef die off,
acidification of the oceans, more frequent
and intense wildfires, changes in global ocean
circulation, and thawing of permafrost in the
polar regions (releasing methane, a powerful
greenhouse gas, leading to even more
warming).