Environmental Science Ch' 7: Atmosphere and Climate

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Environmental Science Ch. 7Atmosphere and
Climate
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Ch. 7-1 The Atmosphere

• Key Terms
• Atmosphere

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California Content Standards for Science
Addressed

• Earth Science
• 8. Life has changed Earth's atmosphere, and
  changes in the atmosphere affect conditions for
  life. As a basis for understanding this concept
• 8(a)Students know the thermal structure and
  chemical composition of the atmosphere.
• 8(b)Students know how the composition of Earth's
  atmosphere has evolved over geologic time and
  know the effect of outgassing, the variations of
  carbon dioxide concentration, and the origin of
  atmospheric oxygen.
• 8(c)Students know the location of the ozone layer
  in the upper atmosphere, its role in absorbing
  ultraviolet radiation, and the way in which this
  layer varies both naturally and in response to
  human activities.

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Why Do I Need To Know This?

• Because we need to understand when and why it
  rains, is sunny, or is any other atmospheric
  condition.
• Because humans are completely altering the nature
  of our atmosphere, which could cause major
  problems for the entire world.

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Key Sections Ch. 7-1

• The Atmosphere
• How Photosynthesis Changed the Atmosphere
• The Five Layers

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The Atmosphere

• The Earths atmosphere is the reason why the
  Earth is not a boiling hot planet like Venus or a
  frozen wasteland like Mars.
• The Earths atmosphere also protects all living
  things from harmful radiation from the sun.
• The Earths atmosphere is approximately 78
  Nitrogen, 21 Oxygen and 1 other gases.

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How Photosynthesis Changed The Atmosphere

• Certain plants and bacteria have changed our
  atmosphere overtime through a process called
  photosynthesis.
• In photosynthesis, plants and animals inhale CO2
  and exhale oxygen.
• Most animals inhale oxygen and exhale CO2.
• So, the balance of oxygen and CO2 remains the
  same in the atmosphere.

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The Five Layers

• The Earths atmosphere is divided into 5 layers.
• The layers are divided by temperature and
  density.
• Each layer plays an important role for life on
  Earth.
• The 5 layers are
• The Troposphere
• The Stratosphere
• The Mesosphere
• The Thermosphere
• The Exosphere

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The Five Layers
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Ch. 7-2 Climate

• Key Terms
• Climate
• Weather

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California Content Standards for Science
Addressed (part 1)

• Earth Science
• 5 Heating of Earth's surface and atmosphere by
  the sun drives convection within the atmosphere
  and oceans, producing winds and ocean currents.
  As a basis for understanding this concept
• 5(a) Students know how differential heating of
  Earth results in circulation patterns in the
  atmosphere and oceans that globally distribute
  the heat.
• 5(b) Students know the relationship between the
  rotation of Earth and the circular motions of
  ocean currents and air in pressure centers.
• 5(e) Students know rain forests and deserts on
  Earth are distributed in bands at specific
  latitudes.
• 5(f) Students know the interaction of wind
  patterns, ocean currents, and mountain ranges
  results in the global pattern of latitudinal
  bands of rain forests and deserts.
• 5(g) Students know features of the ENSO (El Niño
  southern oscillation) cycle in terms of
  sea-surface and air temperature variations across
  the Pacific and some climatic results of this
  cycle.

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California Content Standards for Science
Addressed (part 2)

• Earth Science
• Climate is the long-term average of a region's
  weather and depends on many factors. As a basis
  for understanding this concept
• 6(a) Students know weather (in the short run) and
  climate (in the long run) involve the transfer of
  energy into and out of the atmosphere.
• 6(b) Students know the effects on climate of
  latitude, elevation, topography, and proximity to
  large bodies of water and cold or warm ocean
  currents.
• 6(c) Students know how Earth's climate has
  changed over time, corresponding to changes in
  Earth's geography, atmospheric composition, and
  other factors, such as solar radiation and plate
  movement.
• 6(d) Students know how computer models are used
  to predict the effects of the increase in
  greenhouse gases on climate for the planet as a
  whole and for specific regions.

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Why Do I Need To Know This?

• Because every day we are affected by climate,
  whether the weather is sunny, cold, or rainy.
• Because where we live on the planet plays a major
  role in determining the type of climate that we
  have.
• Because if humans do not stop polluting, we will
  dramatically alter the climate for every region
  on the planet.

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Key Sections Ch. 7-2

• Climate
• What Determines Climate
• Latitude
• Atmospheric Circulation Patterns
• Ocean Circulation Patterns
• Local Geography
• Seasonal Change In Climate

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Climate

• Weather is simply what is happening in the
  atmosphere at a particular place at a particular
  moment.
• For example, if it is raining outside, then that
  is our weather.
• Climate is the average weather in an area over a
  long period of time.
• For example, it does not rain here very often,
  which is why our climate is a semi-desert.
• Most weather occurs in the troposphere.
• The important aspects of climate are
• Temperature
• Humidity
• Wind
• Precipitation

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What Determines Climate

• There are several factors that determine climate.
  
• The most important factors for determining
  climate are
• Latitude
• Air Circulation
• Ocean Currents
• Local Geography
• Of all of these factors, latitude is the most
  important factor for determining climate.

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Latitude

• Latitude is the measure of how far north or south
  of the equator an area is.
• Latitude strongly influences the climate because
  it determines how much sunlight and how direct
  the sunlight is at that location.
• The more sunlight and the more direct the
  sunlight, the more energy in the atmosphere it
  will be, and the warmer it will be.

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Atmospheric Circulation Patterns

• To understand global wind patterns, you need to
  understand how heat is distributed in the
  atmosphere.
• Hot air rises, and cold air sinks.
• As hot air rises, it spreads out and sucks cold
  air in to replace it.
• Eventually the hot air loses its energy and sinks
  back down to the Earth.
• Because the Earth spins, it causes the atmosphere
  to spin in a process called the Coriolis Effect.

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Atmospheric Circulation Patterns

• Because the Earth receives different amounts of
  sunlight at different latitudes, it creates
  global wind patterns as follows

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Ocean Circulation Patterns

• Ocean current patterns also have a large affect
  on climate because water stores a large amount of
  heat.
• Major ocean currents, such as El Nino,
  redistribute the Earths heat, causing rain,
  hurricanes, typhoons, etc.
• Areas near oceans tend to have more moderate
  climates as a result.

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Local Geography

• Local geography, such as the height above sea
  level can have a major effect on climate.
• Two areas with similar latitudes can have very
  different climates due to local geography!

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Seasonal Changes In Climate

• The Earths seasons have to due with the planets
  tilt on its axis.
• Because the Earth is tilted 23 degrees, it does
  not receive the same amount of sunlight
  throughout the year.
• Spring and Fall occur when the Earth is closest
  to the sun.
• Summer and Winter occur when the Earth is
  furthest from the sun.

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Worlds Climate Regions
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The Worlds Biomes
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Ch. 7-3 Greenhouse Earth

• Key Terms
• Global Warming
• Greenhouse Effect
• Greenhouse Gases

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California Content Standards for Science
Addressed

• Earth Science
• 4(c) Students know the different atmospheric
  gases that absorb the Earth's thermal radiation
  and the mechanism and significance of the
  greenhouse effect.
• 4(d) Students know the differing greenhouse
  conditions on Earth, Mars, and Venus the origins
  of those conditions and the climatic
  consequences of each.
• 6(d) Students know how computer models are used
  to predict the effects of the increase in
  greenhouse gases on climate for the planet as a
  whole and for specific regions.

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Why Do I Need To Know This?

• Because every time we pollute the air, we are
  altering the Earths atmosphere, which most
  likely alter the Earths climate.
• Because there is still time to stop the pollution
  and help repair our atmosphere.
• Because it is not a good idea to conduct an
  experiment with the atmosphere that could
  seriously alter the planet.

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Key Sections Ch. 7-3

• Greenhouse Earth
• The Greenhouse Effect
• More Carbon Dioxide In Our Atmosphere
• Where is the Extra Carbon Dioxide Coming From?
• Greenhouse Cases and the Earths Temperature
• A Warmer Earth
• Weather Patterns
• Agriculture
• Sea Levels
• Slowing the Temperature Change

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Greenhouse Earth

• The sun emits light, which heats the planet.
• Some gases are better at trapping and storing
  heat than other gases.
• CO2 and H2O are two examples of gases that are
  really good at trapping and storing heat.
• The more heat that is trapped and stored, the
  hotter the atmosphere becomes.

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The Greenhouse Effect

• The Earths atmosphere is like a greenhouse.
• The glass in the greenhouse lets light and energy
  in, but does not let it out.
• So, the greenhouse can stay warm in the winter
  because it is storing heat, much like our
  atmosphere does.

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The Greenhouse Effect
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More Carbon Dioxide In Our Atmosphere

• In 1958, scientists measured that there were 314
  molecules of CO2 for every million molecules of
  atmosphere.
• By 1994 the amount of CO2 had risen to 358
  molecules for every million molecules of
  atmosphere!

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Where is the Extra Carbon Dioxide Coming From?

• CO2 comes from the burning of any fossil fuel.
• Examples of Fossil Fuels are coal, oil, gas, and
  wood.
• Most electricity comes from coal or oil power
  plants, so just about anything that uses
  electricity or burns fossil fuels is emitting CO2!

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Greenhouse Gases and the Earths Temperature

• Scientists have measured ice cores from the north
  and south pole to determine the amount of CO2 in
  the atmosphere and ancient temperatures.
• They have found out that over the past several
  hundred thousand years that the Earths
  temperature is directly related to the amount of
  CO2 in the atmosphere!
• So, what will happen if the amount of CO2 in the
  atmosphere rises?!?!?

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A Warmer Earth

• Scientists are not 100 certain what would happen
  in a warmer Earth.
• A warmer Earth could affect
• Weather Patterns
• Agriculture
• Sea Levels
• Scientists are constantly trying to develop more
  and better computer models to try and predict
  what will happen if the Earth becomes warmer.
• The one thing that almost ALL scientists agree
  upon is that the Earth will become warmer over
  the next 100 years.

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Weather Patterns

• As the atmosphere warms up, it may cause more
• Tornados
• Typhoons
• Hurricanes
• Massive Thunderstorms
• This is because there will be more energy and
  heat in the atmosphere.

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Agriculture

• If the Earth heats up, it could hit farmers very
  hard, as the main areas where we grow crops are
  likely to become much hotter.
• If we are unable to grow as many crops, it could
  lead to massive starvation and extinction for
  many species!

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Sea Levels

• As the polar regions warm, the polar ice caps
  will most likely melt, raising sea levels.
• It is estimated that the sea level would rise by
  as much as 300 feet if all the ice caps melted!
• Many of the biggest cities in the world are
  located near the ocean, so this could present a
  major problem for populations!

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Slowing The Temperature Change

• The two biggest ways that we can reduce the
  amount of CO2 in our atmosphere are to
• Reduce the amount of fossil fuels that we burn
• Plant more trees and create more open spaces so
  that they remove more CO2 from our atmosphere.
• Neither option is easy or cheap, but the risks
  for doing nothing are far worse!

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Ch. 7-4 The Ozone Shield

• Key Terms
• Ozone

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California Content Standards for Science
Addressed

• Earth Science
• 8. Life has changed Earth's atmosphere, and
  changes in the atmosphere affect conditions for
  life. As a basis for understanding this concept
• 8(a)Students know the thermal structure and
  chemical composition of the atmosphere.
• 8(b)Students know how the composition of Earth's
  atmosphere has evolved over geologic time and
  know the effect of outgassing, the variations of
  carbon dioxide concentration, and the origin of
  atmospheric oxygen.
• 8(c)Students know the location of the ozone layer
  in the upper atmosphere, its role in absorbing
  ultraviolet radiation, and the way in which this
  layer varies both naturally and in response to
  human activities.

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Why Do I Need To Know This?

• Because the ozone layer protects all life on the
  planet from harmful radiation that would kill
  life on the planet.
• Because humans are emitting pollution that
  destroys the ozone layer, which has become a
  major problem!

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Key Sections Ch. 7-4

• The Ozone Shield
• Ozone Eaters
• Breaking Apart CFCs
• The Ozone Hole
• The Effects of Ozone Thinning
• Stopping the Ozone Eaters

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The Ozone Shield

• Ozone is a special molecule of oxygen that has
  three atoms of oxygen.
• Although it is toxic to breathe, it does an
  incredible job of blocking harmful radiation from
  the sun.
• The ozone layer is located in the upper
  atmosphere.

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Ozone Eaters

• Certain chemical compounds, called CFCs, were
  used in air conditioning units, refrigerators,
  spray cans, and in making plastic.
• At the Earths surface, CFCs are very stable and
  therefore very useful compounds.

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Breaking Apart CFCs

• In the upper atmosphere, the CFC molecules break
  apart due to energy from the sun.
• When the CFCs break apart, they begin to react
  with ozone in the upper atmosphere.
• One single molecule of CFC can destroy up to
  10,000 molecules of ozone!

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Ozone Eaters
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The Ozone Hole

• In 1985, scientists discovered that the amount of
  ozone over Antarctica had thinned between 50 and
  98!
• Soon thereafter, scientists discovered that the
  ozone over the Arctic region had also thinned by
  just as much!
• By 1997, the amount of ozone over Canada had
  thinned by 45 as well!

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The Ozone Hole
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The Effects of Ozone Thinning

• If more UV radiation is allowed into our
  atmosphere, this can have a major impact on human
  health. Some side effects include
• Cataracts and eye damage
• Skin cancer
• Weaker immune systems
• Lower crop production
• Extinction for many species that we need.

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Stopping Ozone Eaters

• To help prevent the complete destruction of the
  ozone layers, most countries agreed to do the
  following
• Stop producing CFCs
• Stop producing other harmful substances that
  destroy the ozone layer
• Help cleanup those sources of pollution to speed
  up the ozone layers recovery.