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Global Systems
1. Describe how the relationships among input solar energy, output terrestrial energy and energy flow within
the biosphere affect the lives of humans and other species
a. explain how climate affects the lives of people and other species, and explain the need to investigate climate
change
b. identify the Sun as the source of all energy on Earth
c. analyze, in general terms, the net radiation budget, using per cent; i.e., solar energy input, terrestrial energy
output, net radiant energy
d. describe the major characteristics of the atmosphere, the hydrosphere and the lithosphere, and explain their
relationship to Earth’s biosphere
e. describe and explain the greenhouse effect, and the role of various gases—including methane, carbon dioxide
and water vapour—in determining the scope of the greenhouse effect
Biosphere:
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Another name for the surface of the earth; it is composed of all parts that sustain life
It is composed of 3 divisions
The atmosphere: the layer of air around the earth
The hydrosphere: the water (marine and freshwater) on the surface of the earth
The lithosphere: the land surface not covered by water
Atmosphere:
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is composed of 78% nitrogen gas, 21% oxygen gas, and less than 1% argon, carbon dioxide, and numerous
other gases
is divided into several layers, from the bottom up they are: troposhere, stratosphere, ionosphere, and
magnetosphere
the stratosphere (15-50 km) contains the important gas ozone, composed of 3 atoms of oxygen whereas
oxygen gas is only 2 atoms of oxygen. The ozone layer is concentrated around 15-30 km above the earths
surface
Ozone absorbs harmful UV-b radiation preventing most of this radiation from reaching the surface of the
earth. There are 3 types of UV radiation: UV-a is least harmful and not blocked out by the atmosphere, UV-b
is more harmful causing skin cancer in increased exposure, and UV-c the most damaging radiation, which is
totally blocked out by the upper layers of the atmosphere.
Over the last 40-50 years chloroflorocarbons, produced as a propellant for aerosol cans (spray cans and
bottles) has been destroying the ozone layer. UV light in the upper atmosphere decomposes CFC’s releasing
the chlorine atom. This atom will react with ozone, breaking ozone into normal oxygen which does not block
out the UV-b radiation. In the late 1980’s and international ban on CFC’s has slowly had a levelling off effect
on the rate of ozone depletion.
The carbon cycle and the greenhouse effect
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Carbon dioxide is produced during fossil fuel combustion
Carbon dioxide allows light to pass through but traps reflected heat. This is the greenhouse effect
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The greenhouse effect keeps the earth warm and allows life to exist. But too much carbon dioxide can
increase global temp too fast.
This can cause melting of glaciers and icecaps, increasing the level of the ocean, flooding coastal cities,
increased storms, hurricanes, tornadoes, and shifts in global weather and climate
Hydrosphere:
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Water covers nearly 75% of the surface of the earth
Most of this water is marine, or saltwater.
Of the freshwater the majority is locked as ice in the polar ice caps
water makes up 70-99% of all living things
it is the major compound in living cells
needed for digestion, transport, cooling, location where reactions occur
Lithosphere:
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The land mass of the earth covers about 25% of the surface of the earth
Much of this land mass is not liveable by humans (deserts, icecaps, mountain ranges)
The areas of the lithosphere where life exists are divided into regions called Biomes characterized by dominant
vegetation and associated animal species.
Two major life sustaining processes occur here, and in the oceans. Photosynthesis and cell respiration. (write
chemical reactions)
Energy Flow in Global systems
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energy used to sustain life in the biosphere mostly comes in the form of light from the sun.
is generated by fusion reactions in the sun where two hydrogen atoms fuse to form one helium atom. In the
process there is a loss of mass. The mass is converted into energy according to Einstein’s famous equation
E=mc2
The energy released is in the form of the electromagnetic spectrum (gamma, UV, visible, infrared, radio, TV, )
the sun is too far away to feel any heat, plus the vacuum of space prevents heat from being transmitted
through space
the visible light reaches the outer atmosphere and from here down to the earth surface it gets reflected and
absorbed by different parts of the biosphere
is reflected by the upper atmosphere, scattered by the atmosphere and clouds, absorbed by the surface,
absorbed by oceans and used for wind and waves, absorbed by plants for photosynthesis, reflected by the
surface (lithosphere)
Ultimately all energy received by the earth is reradiated back into space in the form of heat. The energy the
earth receives over the long term always balances the energy it gives off. This satisfies the first law of
thermodynamics. The second law of thermodynamics states that when energy is converted from one form to
another the conversion is never 100% efficient. Much of the energy is lost as heat. This is the heat radiated
from the atmosphere, lithosphere, and hydrosphere. Overall energy always flow through a system, it drives
the system. It may be temporarily stored, and given off later, it may be changed from one form to another,
but it is never lost. Energy flows, which in turn causes matter to cycle and life to exist
Examples of conversions that release heat are decomposition and muscle contractions
The suns energy produces life on earth through the processes of photosynthesis and cell respiration. Less
than 1% of the energy that reaches the biosphere is used for photosynthesis. This is the energy that is
transferred through all food chains and food webs. It is the energy that is inside every cell of every living
organism.
2. Analyze the relationships among net solar energy, global energy transfer processes—primarily radiation,
convection and hydrologic cycle—and climate.
a. describe, in general terms, how thermal energy is transferred through the atmosphere (i.e., global wind
patterns, jet stream, Coriolis effect, weather systems) and through the hydrosphere (i.e., ocean currents, large
bodies of water) from latitudes of net radiation surplus to latitudes of net radiation deficit, resulting in a variety of
climatic zones
b. investigate and describe, in general terms, the relationships among solar energy reaching Earth’s surface and
time of year, angle of inclination, length of daylight, cloud cover, albedo effect and aerosol or particulate
distribution
c. explain how thermal energy transfer through the atmosphere and hydrosphere affects climate
d. investigate and interpret how variations in thermal properties of materials can lead to uneven heating and
cooling
e. investigate and explain how evaporation, condensation, freezing and melting transfer thermal energy; i.e., use
simple calculations of heat of fusion Hfus= n Q and vaporization Hvap= n Q , and Q=mc t to convey amounts of
thermal energy involved, and link these processes to the hydrologic cycle
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The energy that reaches the earth’s surface is not always evenly distributed. Variables such as cloud cover,
latitude, and albedo influence the amount of solar radiation that part of the earth receives. This results in
differences in weather and climate at different times of the year in different locations.
Latitude - the position on the Earth relative to the equator. The location on the Earth determines the angle of
incoming solar radiation and therefore the amount of light absorbed, and heat given off, at that latitude.
The latitude of an area on the earth will also influence how much solar radiation that area receives at different
times of the year. The earth is tilted on its axis approximately 23 degrees. As the earth orbits around the sun
this tilt causes the northern hemisphere (as compared to the southern hemisphere) to be more exposed to
the direct rays of the sun for half of the year and then when the earth is in the opposite side of its orbit the
northern hemisphere will be less exposed to the direct rays of the sun for the other half of the year. This
variation causes a warming trend in the Northern Hemisphere, our spring and summer during march to
august, and a cooling trend, our fall and winter during September to February. We know these as the seasons.
The opposite pattern exists in the Southern Hemisphere.
The surface feature of the land often influences how much energy is absorbed. The term used to describe the
amount of light reflected off a surface (hence the amount of energy it absorbs) is Albedo. The higher the
albedo of a surface the less light and energy it absorbs (it reflects more light and is brighter or shinier). An
example is a snow covered field vs an unplanted, dark soil surface. The snow has a high albedo, it reflects a lot
of light, therefore it absorbs very little light, absorbing less energy and heating up slower. The dark field,
however, reflects very little light, absorbing most of the light it receives, absorbing more energy and heating
up faster. This creates “thermals” over dark fields. Thermals are areas of rising air currents created by
warmer, less dense air. Birds, especially predators, are often seen flying/gliding over/in these thermals; the
rising air keeps them aloft with very little wing flapping on the part of the bird.
Clouds have high albedo, consequently the surface below the clouds does not receive as much light as an area
with fewer clouds.
Climate- the prevailing weather conditions of a place as determined by temperature, precipitation, wind,
clouds, and sunlight over a period of years.
Weather- the general conditions of the atmosphere at a particular time and place. Ex. Temperature,
precipitation, wind, clouds sunlight. Weather systems are driven by the energy from the sun. Both latitude
and surface features on the Earth affect weather and climate.
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Thermal energy transfer through the atmosphere: global wind patterns, jet stream, Coriolis effect, weather
systems
Currents in the oceans and atmosphere distribute the solar heating from the tropics to the higher latitudes.
Oceans: act as heat sinks. They store large amounts of thermal energy preventing the earth from getting to
hot, but also release this energy preventing the earth from getting too cold.
Ocean currents: once heated the surface water can be mixed downward or can be moved across by wind.
Surface ocean currents are created by surface wind and their directions are influenced by land masses.
Global wind patterns: are produced by heating at the earth’s surface. The surface heating causes convection
(the circulation and distribution of air). Warm air rises (is less dense) and cold air falls (is more dense). Areas
of cool air form high pressure systems that push air (wind) to areas of lower pressure or warm air.
Weather systems: large air masses of similar air conditions (weather) are created by heating of the ocean. The
air above the ocean warms by conduction and convection creating the air mass. These will move in response
to wind patterns and the rotation of the earth.
Coriolis effect: The rotational movement of the air masses and currents on the earth produced by the rotation
of the earth. The effect is most evident in large systems and is very difficult to produce in small scale systems.
Air masses rotate clockwise in the northern hemisphere and counterclockwise in the southern hemisphere.
Jet stream: currents of extremely fast moving air about 10-15 km above the earth’s surface. They move in a
west to east directions because this is the direction the earth spins. Friction between the earth and the
atmosphere at ground level pulls the air in the direction of rotation.
Gulf Stream: a 100 km wide “river” of ocean water that starts in the Caribbean and goes to Newfoundland. It
follows the east coast of North America
El Nino: a global weather change caused by warm ocean currents moving in different directions than normal.
Ex. Warm pacific water moves north along the west coast of North America creating warmer than usual air
masses in the western U.S and Canada.
Unique properties of water influence climate
High heat capacity: Large amounts of energy are needed to change the temperature of water compared to other
substances. Large bodies of water such as oceans and large lakes have a moderating effect on the air temperature
of nearby land communities. Water temperatures change slowly and by small amounts. Large bodies of water
absorb a large amount of light and heat during the day and during the summer, but release the heat slowly at night
and during the winter.
Phase changes:
Water has high heat of vaporization. This is the energy needed to convert water from a liquid to a gas. The
temperature of the water does not change. For water to evaporate a large amount of energy is needed to break
the attractive forces among water molecules. The opposite occurs during condensation. For water to form a
liquid, it must lose a lot of energy to allow enough molecules to come together and form bonds or attractive forces
to pull the molecules closer to each other. Water evaporates when the molecules absorb enough heat to have
sufficient kinetic energy to break loose from their neighbouring molecules. This heat can be absorbed from
sunlight, from air at the water’s surface, or from other water molecules. When heat is absorbed from other water
molecules, they lose energy and cool. This is known as evaporative cooling and it causes bodies of water to remain
at a relatively stable temperature. When it rains the clouds release this energy causing a slight warming of the air.
Water has high heat of fusion. This is the energy released to convert water from a liquid state to a solid state
(freezing). When water freezes it releases thermal energy, the temperature of the water does not change. When
water melts it absorbs thermal energy but the temperature does not change. In spring, the days become linger
and the sun begins to warm the land (the sun rises higher off the horizon, more direct sunlight). If large amounts of
snow and ice remain from the winter, then much of the suns energy is used to melt them. Therefore, the air
temperature does not rise as much as it would in the absence of snow and ice. As winter sets in, the days get
shorter and the sun provides less heat than in summer. As liquid water freezes, however, it releases heat.
Therefore, the air temperature does not drop as much as it would if there were no water to freeze.
Thermal Energy
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Also called internal energy
The total kinetic of all the particles in a substance
The sum of all the vibrations and of the particles
Units for energy are in Joules (J)
Kinetic Energy
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Is the energy of motion
Is the translational (shaking/vibration) or rotational motion of the particles
Potential Energy
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Is stored energy
Produced or stored in the forces between the molecules that determine the state of matter
It is the forces that hold the molecules together in that state
Temperature
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The average kinetic energy of the particles in a substance
Different systems are used to measure temperature. These systems are called temperature scales
There are three different scales: Celsius, Kelvin, Fahrenheit
Kelvin Scale: (K) there are no negative temperatures, zero is the lowest. This is the point at which there is
no more motion of the particles; no kinetic energy (0 degrees K). Water freezes at 273 K, boils at 373 K.
Celcius: The lowest temperature is -273 C, water freezes at 0 C and boils at 100 C
K = C + 273
Heat
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Is the transfer of thermal (internal) energy
Is measured in Joules (J)
When there is a difference in temperature between two locations thermal energy (heat) will transfer. The
faster movement of particles in one area will bump into the slower moving particles in the other area,
speeding the slow up and slowing fast particles down.
Heat always travels from a hot area to a cold area until it reaches thermal equilibrium
Thermal equilibrium occurs when there is no net transfer of heat, when the two areas are at the same
temperature (all their particles are vibrating with the same speed.
Conduction
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The transfer of thermal energy due to the collision of particles (no net movement of substance)
Solids are good conductors b/c particles are more tightly bound allowing for easier collisions.
Metals are the best b/c electrons are more mobile
Convection
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The movement of fluid particles from warmer areas to cooler areas
Occurs best in liquids and gases b/c the particles are more free to move among themselves
Radiation
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The transfer of energy in a wavelike form
It does not require a medium to travel through
Calculating Thermal Energy
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Is a function of three variables:
Mass, the amount of matter present, the more matter the more energy
Temperature, how fast all the matter or particles are vibrating
Specific heat capacity. The amount of heat (thermal energy) it takes to increase the temperature of 1.0 g
of a substance by 1 degree C
Different substances have different “c”. They have different types and numbers of particles that take
different amounts of energy to move.
Units are J/gC . Ex. Pure water 4.19, aluminum .903, copper 3.85, lead .130
Q = mc ∆ t
Q = thermal energy in Joules or kilojoules
m= mass in g or kg
c= specific heat capacity
∆ t = the change in temp, in Celsius
Heat of fusion
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Also called specific latent heat of fusion
The amount of heat required to melt 1 g of a substance. Units are J/g
Heat of vaporization for water = 2260 J/g
This is also the heat given off if the substance freezes.
Q = m Hfus
Heat of vaporization
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Also called specific latent heat of vaporization
The amount of heat required to evaporate 1.0 g of a substance. Units are J/g
This is also the amount of heat given off when a substance condenses,
Q= mHvap
Heat of fusion for water = 334 J/g
3. Relate climate to the characteristics of the world’s major biomes, and compare biomes in different regions of
the world
a. describe a biome as an open system in terms of input and output of energy and matter and exchanges at its
boundaries
b. relate the characteristics of two major biomes (i.e., grassland, desert, tundra, taiga, deciduous and rain forest)
to net radiant energy, climatic factors (temperature, moisture, sunlight and wind) and topography (mountain
ranges, large bodies of water)
c. analyze the climatographs of two major biomes (i.e., grasslands, desert, tundra, taiga, deciduous and rain forest)
and explain why biomes with similar characteristics can exist in different geographical locations, latitudes and
altitudes
d. identify the potential effects of climate change on environmentally sensitive biomes
Biomes: The biosphere contains many types of ecosystems. The can be divided into terrestrial (land) and aquatic
(water) ecosystems. Terrestrial ecosystems are also called biomes
Tundra
Taiga
Temperate
deciduous
rain forest
Tropical rain
forest
Grassland
Desert
Polar
regions
Immediately
south of
tundra
Midway
between
poles and
equator
Equatorial
Midway
between
poles and
equator
Middle to
equatorial
Very little,
mostly
snow
35-40 cm/yr
snow,
rain,fog
100 cm/yr
snow and
rain
200 and
more cm/yr
25-75 cm/yr
Less than 25
cm/yr
Low, below
zero
Zero to +5
Warmer
than taiga
+20-+25
Similar to
forest but
dryer
Hot during
day cold at
night
Shrubs,
low
flowering
plant, no
trees
Coniferous
trees,
shrubs,
lichens
Coniferous
and
deciduous
trees,
flowering
plants
Lots of trees
and
flowering
plants,
dense
vegetation
Mostly
grasses,
some trees,
some shrubs
Cactus, very
little
vegetation
Rodents,
hares,
caribou
Bison, hare,
moose,
wolves, bear
Insects,
birds, deer,
squirrels
Insects,
birds,
reptiles,
amphibians,
primates
Snakes,
burrowing
animals,
coyotes
Reptiles,
insects,
birds.
Factor
Location
Precipitation
Avg. Annual
temperature
plants
animals
Climatograms
One method of illustrating this variation in energy absorption is through climatograms. A climatogram is a two in
one graph that illustrates the average monthly precipitation and temperature of a given location. The precipitation
is illustrated as a bar graph while the temperature is illustrated as a line graph. Temperature curves that are
higher in the middle of the graph (July and August) are associated with northern hemisphere countries while the
opposite is for southern hemisphere countries. Temperature lines that are relatively flat (constant temperature
year round) indicate a tropical location while the steeper the line the more polar the location. Amounts of
precipitation provide an indication of the dominant vegetation that will be found in the location. Consequently,
this provides information about the general types of animals that could be found in the location.
4. Investigate and interpret the role of environmental factors on global energy transfer and climate change
a. investigate and identify human actions affecting biomes that have a potential to change climate and critically
examine the evidence that these factors play a role in climate change
b. identify evidence to investigate past changes in Earth’s climate
c. describe and evaluate the role of science in furthering the understanding of climate and climate change through
international programs
d. describe the role of technology in measuring, modelling and interpreting climate and climate change
e. describe the limitations of scientific knowledge and technology in making predictions related to climate and
weather
f. assess, from a variety of perspectives, the risks and benefits of human activity, and its impact on the biosphere
and the climate
Climate change: a change in the average atmospheric conditions in an area.
Most often this refers to global climate change, but is most often measured in location changes in the patterns of
weather over prolonged periods of time.
Most often measured in changes in average temperatures in the different seasons, changes in rainfall amounts and
distribution, ocean temperatures and different depths, ice depth and range of glaciers and polar icecaps.
Generally most scientists agree that the earth is very slowly warming up. There are some scientists who disagree
and argue that it will be cooling down over the next 100 years.
Role of technology in Climate Change
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Ice core samples: atmospheric gases are trapped in ice as glaciers are produced. Analysis of these gases
provides information about carbon dioxide and other gas concentrations in the atmosphere hundreds of
thousands of years ago, depending on how old the ice sample is.
Pollen samples: Pollen are reproductive cells from plants. Finding pollen in soil and ice samples from
thousands of years ago provides information about the types and abundance of plants that grew in an area.
The plants that grow in an area indicate the climate of that area at that time.
Computer models: Use past data from weather and climate patterns to predict future weather and climate,
both short term (tomorrows weather) and long term (climate change of the earth)
Satellite imagery: Determines the temperature, concentration of gases in the atmosphere, tracks storms
development and movement, tracks ocean current and air current movements.
Limitations of scientific knowledge and predictions about weather and climate
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Weather and climate are influenced by many large and small scale factors simultaneously, this requires a lot of
information to be processed simultaneously, it is a very complex system.
Computer models do not have all the information because we do not fully understand all factors involved
Predictions and conclusions drawn from models are not 100% reliable. Short term predictions of weather are
more reliable (have greater confidence) but long term predictions of weather are not as reliable. Long term
predictions of climate are generally accurate because climate is a general description. Predictions of climate
change and how much change will happen are not as accurate because of the complexity of the system
Human Activity and its impact on the Biosphere and Climate
Human Activity
Risks
Combustion of fossil fuels
Increased greenhouse effect and
increased global warming
Benefits
Jobs for people in communities,
more money for countries for
health care and education.
Loss of ecosystems
Species extinction
Creates business, economic
growth
Damage to cities and human
made structures
Deforestation
Loss of ecosystems
Lumber to be sold
Species extinction
Crops to harvest
Increased global warming
Creates jobs
Soil erosion and damage to
aquatic ecosystems
Money for countries for health
and education
Factors Causing Climate Change and Change in Biomes and Aquatic Ecosystems
Environmental factors:
Continental drift (geological events/processes)
The continents are slowly moving. This causes changes in ocean currents, air currents and precipitation patterns.
This also causes different amounts of light to be absorbed at different latitudes. These changes result in a different
distribution of thermal energy over the biosphere.
Solar cycles
The sun produces different amount of light in its lifetime affecting the amount of light received by the Earth.
Meteors and volcanic eruptions
These produce large amounts of dust and gas that can enhance the greenhouse effect.
Oceans
Absorb and release greenhouse gases thus influencing the greenhouse effect
Earth’s Tilt
This varies between 22 and 24 degrees over a 100,000 year cycle. This can affect the amount of light absorbed at
different latitudes and the amounts of thermal energy produced at those latitudes.
Human Factors:
Fossil fuel combustion
Humans are adding large amounts of greenhouse gases by burning fossil fuels (coal, oil, natural gas). Carbon
dioxide concentration in the atmosphere has increased 31% since 1750.
Deforestation
Clear cutting and burning large amounts of forest adds dust and carbon dioxide to the atmosphere. But this also
reduces the earth’s ability to remove carbon dioxide from the atmosphere. Trees, and all other plants, perform
photosynthesis which removes carbon dioxide from the atmosphere.
Evidence for past changes in Earth’s climate
Gases trapped in glacier ice (hundreds of thousands of years old) tell us the concentration of gases in the
atmosphere during that time period
Pollen samples in fossils and plant fossils in old rocks tell us what vegetation was in that area during that time
period. The vegetation tells us indirectly what the climate was like then
Tree rings reflect the growth of the tree in the growing season (summer)
Examining old trees (thousands of years) we can determine how warm the climate has been in the recent past