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Unit 4 Climate Change
Day 1 A closer look at Earth (pg 502)
The main components of the earth that influence the weather are
The ________________
The _____________ forms
The ______________ in its various forms (solid, liquid gas)
WEATHER -
refers specifically to the environmental conditions that occur at a particular place at a particular
time. These include temperature, air pressure, cloud cover, and precipitation.
CLIMATE -
is the average weather conditions that occur in a region over a long period of time, usually a
minimum of ____ years. The description of the climate of a region includes average monthly
temperatures and precipitation, average wind speed and direction, and a variety of other data
The climate of an area is affected by many factors. The four main factors are:
• latitude
• elevation
• the air masses that flow over the area
• the area’s nearness to large bodies of water
-
Climate Zones
- early 1900s – temperature, precipitation and plant communities
2
5 Zones :
1.
2.
3.
4.
5.
Tropical - _________________________ and ___________________________________
Moderate - _____________________, ___________________ and
______________________________
Polar _____________________, ____________________ and
_____________________________
Dry _____________________ and _________________________________
Continental _______________________ and ______________________________
Ecoregions
-
based on landforms, soil, plants, animals and climate
Ontario is divided into western great lakes forest, Midwestern Canadian shield forests, southern Hudson
bay taiga, central Canadian shield forests, eastern forest boreal transition, eastern great lakes lowland
forest and southern great lakes forests
Bioclimate Profiles
-
series of graphs that show temperature and moisture conditions at a given location.
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4
5
Earths Climate System
-
complex set of components that interact with each other to produce earths climate
include land, liquid water, ice and living things
The Sun: Source of All Energy
-
Almost all the energy on Earth is initially solar radiation —transmitted as waves that radiate from the
Sun.
-
In general, regions at or near the equator receive more solar radiation per square metre than regions
closer to the poles do
-
radiation may have 3 fates : ___________by the particle causing the particle to gain energy, ___________
through the particle or may be ________________ off the particle
Some of the solar radiation that strikes Earth is absorbed by Earth’s surface. ____________energy is the
total ____________ energy of the particles in a substance. A quantity of a substance at a high temperature
has more thermal energy than the same quantity of that substance at a lower temperature.
Earth’s biosphere is home to all living things and the physical environment that supports them. All
organisms live in the lower atmosphere, on the surface or just below the surface of the lithosphere, and in
the hydrosphere.
-
-
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Day 2 The Atmosphere - is the layer of gases that extends outward about 300 km from the surface of Earth.
Layers of the Atmosphere ( pg 510)
Write down the five layers of the atmosphere, starting with the layer closest to the earth’s surface. Then, fill in the
table below with the correct information about each layer.
layers of
atmosphere
Pg 513 ( 2,3,5 )
distance from
earth
characteristics
what flies there
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The Lithosphere -
is the solid portion of Earth that floats on the semifluid portion of the mantle
-
extends downward from Earth’s surface and varies in thickness from as little as 5 km thick beneath parts of
the oceans to as deep as 100 km beneath the continents.
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The science of plate tectonics describes how the different plates of Earth’s lithosphere move over the
mantle. When plates collide, they may push up mountains, although this can take many millions of years.
The sides of mountains on which the wind blows receive most of the moisture from the clouds, while the
leeward side can be dry : rain shadow effect
The Hydrosphere( pg 522 )
-
The hydrosphere includes all of the water on Earth. About 97 percent of this water is salt water in Earth’s
oceans. The other 3 percent is fresh water and includes liquid water, such as in groundwater, lakes, and
streams, and frozen water, such as the ice in snow and glaciers.
water heats up and cools down more slowly than land thus regions near an ocean or large lake tend to be
cooler in the summer than inland; also warmer in the fall as the water slowly emits stored thermal energy
regions downwind from large bodies of water have more snowfall in the winter
ice covered in snow reflect more radiant energy than surfaces covered with soil, rock and vegetation ; thus
cold
The Natural Greenhouse Effect
-
absorption of thermal energy by the atmosphere
Most of this radiation is absorbed as thermal energy in the atmosphere by clouds and gases such as water
vapour, carbon dioxide (CO2), and methane (CH4).
The natural greenhouse effect helps keep the temperature of our planet in the range that supports life.
Water vapour, carbon dioxide, nitrous oxide, and methane are called _________________ gases
_______________________ is the main contributor to the natural greenhouse effect
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-
The average temperature at Earth’s surface in 2007 was 14.7°C. Without the natural greenhouse effect, the
average temperature on Earth would be about −20°C.
Earth’s energy Balance Worksheet (pg 504)
All the energy we need here on earth originates from the sun.
Transfer of Heat
Energy can transferred by four methods.
1. Radiation: is the transfer of energy by means of __________.Radiation waves do not need a
_____________
2. Conduction: is the transfer of energy through the ___________of particles. Conduction occurs most easily
in_____________.
3. Convection: the transfer of energy through the movement of particles in a _________. A _________ can be
either a liquid or a gas.
Reflection and absorption of energy (pg 506)
When energy from the sun hits the earth…________is absorbed by land and oceans ________ is reflected by the
clouds _________ is absorbed by the clouds __________ is reflected by the surface
In general, regions at or near the equator receive more solar radiation per square metre than regions closer to the
poles do . Some of the solar radiation that strikes Earth is absorbed by Earth’s surface. This solar radiation is
converted to ______________energy in everything it touches. Thermal energy is the total __________ energy of
the particles in a substance. A quantity of a substance at a high temperature has more thermal energy than the
same quantity of that substance at a lower temperature. Heat flows from a substance at a ______ temperature to
one at a_______temperature
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10
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considering diagram above : near the equator the sun shines directly overhead ; the energy from the
sun is spread over a small area thus feels very strong ; also the sun passes through less atmosphere
and less radiation is absorbed and reflected.
Closer to the poles the sun is not directly overhead and the energy is spread over a larger area and
feels weaker ; at higher altitudes the sun hits at a angle and thus must pass through more atmosphere
before it hits the earth
Day 3-4 Insolation is the amount of solar radiation received by a region of Earth’s surface. Insolation depends on
latitude, which is the distance of any place on Earth from the equator, shown on a globe by a series of lines drawn
around it parallel to the equator. The equator is at 0° latitude, and the North Pole is at 90° latitude.
Albedo is the __________________ ability of an object. The albedo of our entire planet is about 30 percent
Eg. Clean snow has a ___________ albedo, it ___________ energy Black snow has a ______ albedo, it
____________ energy
Heat sink: is any object that _____________ energy. A heat sink ____________ energy
Heat capacity is the amount of energy required to raise the temperature of _________ of substance ________
Water has a _________ heat capacity. Therefore it can hold a lot of energy in the form of heat.
Unlike a metal such as Aluminum it takes a long time to heat up and a long time to cool down.
Pg. 507 (1-7),10
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12
13
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Review
1.
Define “weather” and “climate” in your own words.
2.
Explain why the Sun is considered the source of almost all the energy on Earth.
3.
State whether each of the following terms is related more to weather or to climate.
(a) cloud cover
(b) annual rainfall
(c) chance of precipitation
(d) average monthly temperature
4.
Explain what happens to the solar radiation that reaches Earth.
5.
What would the average temperature on Earth be without the natural greenhouse effect?
6. State whether the following surfaces would have a high or a low albedo.
7.
Differentiated Instruction
Earth’s annual global net
radiation budget
(a) a mirror
(b) a lawn
(c) a sidewalk
(d) an asphalt driveway
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Pg 513 (2,3,5)
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Day 5 Prevailing Wind Patterns and Major Ocean Currents ( pg 516)
Watch video www.teachersdomain.org : What Causes the Gulf Stream
Why is Earth heated unevenly? What effect does this have on the atmosphere?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
What is the principal cause of surface currents in the ocean?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
If someone asked what the Gulf Stream is, what would you tell them?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
What is the role of wind in the location and movement of the Gulf Stream?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
Use specific examples to explain how the Gulf Stream influences climate.
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
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Convection Current
-
a circular current in air and other fluids caused by the rising of warm fluid as cold fluid sinks
Wind is the movement of air from areas of _______pressure to areas of ________ pressure. The rising and sinking
masses of air in convection currents cause changes in atmospheric pressure, which cause wind.
Prevailing Wind Patterns
Prevailing winds – winds that affect large areas, affecting weather
The Coriolis Effect – the apparent change of direction of a moving object in a rotating system, noticed least at
the ________________ and most near the _____________________
The Coriolis effect is the deflection of any object from a straight-line path by the rotation of Earth. The Coriolis
effect causes moving air or wind to turn right in the northern hemisphere and left in the southern hemisphere.
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Observed Wind Pattern – several important prevailing winds
- the ______________ trade winds (east to west)
- mid-latitude _______________ (west to east)
- _______________ easterlies (east to west)
- _________________ stream (west to east) (high speed winds in the upper regions of the
troposphere)
Causes of Prevailing Winds
- caused by a combination of _____________ currents and Earth’s _______________rotation
- affected by changing seasons
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Effects of Prevailing Winds
- help distribute large amounts of solar energy from equator to the colder parts of the world
- carry moisture, helping to cause different types of precipitation
Major Ocean Currents


oceans are important in weather dynamics
ocean currents absorb a large amount of direct solar radiation and spread it around the world

Causes of Ocean Currents
- _____________currents
- ________________ across the ocean
- influence of Earth’s _________________
- shapes of ____________________
- _____________ capacity of water
- amount of _________________ in the oceans

Effects of Ocean Currents
- temperature of ocean currents affects air above it, thus affecting the weather of __________ cities of the
land it reaches
- affect the pressure of the air above them
Major Ocean Currents (pg 525 )
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vast volume of water at the equator, where radiation from the sun is direct
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direct energy absorbed by the oceans is spread around the world by ocean currents
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Norway & Iceland – Atlantic harbours remain ice-free because of the ____________ stream, an Atlantic Ocean
current that transports warm water from the Gulf of Mexico (see figure 1 pg. 525)
-
cold ocean currents from North Atlantic and Pacific Oceans and the Antarctic circumpolar current flow to the
equator
Causes of Ocean Currents
-
patterns of convection currents, winds across the oceans, Earth’s rotation, shape of continents, heat capacity of
water, and amount of salt in oceans
-
warm water; from equator to the North or South Pole
-
cold water; travels in opposite direction
-
Solar energy strikes the oceans directly at the______________, heats the water and starts
______________currents
-
As warm_____________ dense water moves ___________from the equator, replaced by cooler,
___________water
-
Convection currents also influenced by ________________winds and twisting caused by
_________________effect
-
Close to continents, ocean currents travel along its edge
-
Because of Earth’s eastward rotation, ocean currents on the west sides of the oceans are ______________and
fast moving ___________________________
Currents on East side are _____________ and slower _________ km/h
only one ocean current – the ______________ ________________ travels all the way around the world with
no continents in its way
-
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-
oceans are huge heat _____________________
Salt affects ocean currents, water evaporates leaving an increase of salt water, the saltier, the
_____________dense so it sinks, creating deep water currents and is replaced by warm less dense water
Thermohaline circulation -
the continuous flow of water around the worlds oceans driven by differences in
water temperature and salinity
Effects of Ocean Currents
-
the warmer a body of air, the _______________its ability to hold moisture
Ocean current that reaches Peru is cold so the air above it is dry, therefore coast of Peru is cool and dry –
creates a desert called the Atacama Desert beside the Pacific Ocean
-
Western side of Pacific Ocean, warm waters evaporate, form clouds – precipitation
-
______________currents responsible for coastal regions being cooler in summer and warmer in winter than
regions inland
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January temperature in Ottawa is 30o C lower than average July temperature. In St. John’s difference is only
18o C and Ottawa is farther South than St. John’s
-
St. John’s warmer in winter because of warm, moist air brought northward by the
____________________Stream
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High heat capacity of water causes seasonal changes to lag behind the daylight hour changes because the
water takes a long time to warm up after winter
-
Ocean currents affect the pressure of the air above them, i.e. air above warm ocean currents becomes warmer
and _____________ dense forming ______-pressure systems.
Causes of Prevailing Winds (pg 518)
In the Northern Hemisphere
Tropopause
4
5
2
1
3
7
6
30oN
Latitude
Surface
The convection currents that form at the equator are known as the
Equatorial Convection Currents.
Equator
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1.
Most of the ___________ ___________ reaches Earth at the equator.
This energy is used to heat the surrounding _________, ________ and _________.
2.
As the air is heated its molecules will move ___________ ___________ and expand. This
causes the air to become ___________ ___________ and move in an ___________ direction.
3.
As the air molecules rise it causes an area of ______ ___________ at ground level.
4.
Once in the ___________ the air will move in a ___________ ___________.
5.
When the air reaches a ___________, it will mix with the ___________ air mass. This mixing
causes the air to become ___________ and will fall towards the surface.
6.
As the colder air molecules fall this will generate an area of ______ _____________.
7.
The air molecules will then move from a region of ___________ ___________ to a region of
___________ ___________ in a ___________ direction. The air that moves along the ground
will twist to the ___________.
This convection current results in the ___________ ___________ ___________.
Tropopause
13
12
8
11
9
10
60oN
Latitude
Surface
The convection currents that formed between 30 oN latitude and 60oN latitude are called the Mid-latitude
Convection Current.
30oN
Latitude
8.
The air molecules ___________ ___________ and become ___________ and ___________
towards the surface.
9.
The falling dense air particles cause a ___________-___________ area.
10.
The high pressure will cause the surface wind to move in a ___________ ___________ and twist
to the ___________moving towards 60oN latitude.
11.
The air travels in a northward direction because the air mass is warmer than the air at 60oN latitude.
This warm air will mix with the cooler air resulting in the formation of a ______________________ area.
12.
The incoming warm air will mix with the cooler northern air causing it to become ___________
___________ and will rise. This creating the low pressure area in 11.
13.
Once in the ___________ the air will move in a ___________ ___________.
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This convection current results in the ______________________.
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Tropopause
18
16
15
19
Surface
60oN
Latitude
14
North Pole
14.
The ___________ ___________ air travels in a ___________ direction and mixes with the
warmer air coming from the mid-latitude convection currents.
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&
16
17
As the warm and cold air mixes, it causes the air to become _________ _________. As the air
rises it creates an area of ___________ ___________.
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When the air reaches ___________ ___________, it will mix with the ___________ air
causing the air to become ___________ and fall towards the surface.
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As the colder air molecules fall this generates an area of ___________ __________.
Once in the ___________ the air will move in a ___________ ___________.
The air molecules will than move from a region of ___________ ___________ to a region of
___________ ___________ in a ___________ direction. The air that moves along the ground
will twist to the ___________.
This convection current results in the ___________ ___________.
Effects of Prevailing Winds
Location
weather
Near the equator
two equatorial convection currents
cloudy and rainy
meet and rise
30o north latitude
Cool falling air is dry
Creats desert-like conditions
(Gobi Desert in Asia, Sahara Desert
in Aferica, Sonoran Deserts in North
America)
60o north latitude
Two air systems meet and rise
Unsettled conditions of cloud and
precipitation
Artic regions
Receives no sunlight in winter and
cause a greater temperature
difference between the polar
regions and the equator, which
causes a greater pressure
differences and stronger winds.
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Watch animations : www.teachersdomain.org : Giving Rise to the Jet Stream
The animation describes how warm tropical air is "drawn toward the cold North and South poles." Can you explain
why this is so?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
Why do you think the warm tropical air sinks when it reaches the poles?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
How does Earth's rotation affect the direction of the jet streams?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
How does the jet stream affect the weather where you live?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
_______________________________________________________________________________________________
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Day 6 Jet Streams ( pg 518 )
1
2
3
5000 m
Troposphere
7000 m
Jet streams are high-speed winds in the upper regions of the troposphere, often around the mid-latitudes. They
tend to move from west to east and steer most of the major weather systems, such as low pressure and highpressure systems.
Because of their high altitude, these winds are not subject to much friction and so are much faster than winds
closer to Earth’s surface. Changes in the jet streams affect the formation of severe weather events such as
squalls,storms, and cyclones.
Tropopause
4
Equatorial
Convection
Currents
Solar Energy
Surface
Equator
30oN
Latitude
1.
There is 7000m of troposphere on top of the convection current because the hot air continues to rise.
This creates a ____________ ____________ in this region.
2.
Above the 30o north latitude, there is 5000 m of troposhpere, which generates a ____________
____________ region.
3.
The air will move ____________ from a region of high pressure to a region of low pressure. As it
is moving northwards it will twisting to the ____________.
4.
This results in a ____________-____________, ____________-flowing wind, the jet stream,
around 30o north latitude
A similar type of jet stream can also occur at 60 o north latitude.
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Complete pg 519(1-4), pg 527(1-7) pg 537(1-3,5-7)pg 540(1-5),9-14,16,28
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Key Concept Review
1. Explain what is meant by the term “the natural greenhouse effect.”
2. Study the word “insolation,” and explain why it stands for incoming solar radiation.
3. Why is it important that some of the insolation hitting Earth returns to space?
4. What is thermal energy? What is another name for the absorption of thermal energy by the atmosphere?
5. Define “conduction,” “convection,” and “radiation,” and draw a sketch of each to illustrate their mechanisms of
heat transfer.
6. Explain how the Coriolis effect influences the direction of wind in the northern hemisphere.
7. Describe how thermal energy is transferred in the hydrosphere.
8. Why is the natural greenhouse effect necessary to life on Earth?
9. Explain what would happen to Earth without the natural greenhouse effect.
10. Discuss the scenarios that could occur if Earth’s net radiation budget became unbalanced.
11. State whether each of the following is an example of conduction, convection, and/or radiation. Explain if you
think there is more than one possibility.
(a) You are cooking, and the handle of the spoon you are using to stir the soup starts to feel hot.
(b) A pail of hot water is added to a child’s inflatable pool. After a while, the pool is warm.
(c) You go to the park, and when you sit on a metal bench, it is hot.
(d) You are standing near a barbecue, and you feel the heat on your face.
12. Why are coastal cities attractive to many people seeking a moderate climate?
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Review
1. (a) How does climate differ from weather?
(b) Use an analogy to illustrate the difference between climate and weather.
2. Describe what happens to the insolation received by Earth.
3. How does cloud cover influence the amount of insolation that reaches Earth’s surface?
4. Why does the temperature of the thermosphere vary from –100°C to +1000°C each day?
5. How does the net radiation of a region change with its latitude?
6. In a brief descriptive paragraph, distinguish between the hydrosphere, lithosphere, and atmosphere.
7. Explain the relationship between the troposphere and the survival of humans.
10. What three gases in Earth’s atmosphere are most important in supporting life?
11. What two sources of energy warm the lithosphere? Identify which one is more significant.
12. Explain why the albedo of an area can change with the seasons.
13. Explain how thermal energy is transferred when you take your backpack from inside your home to the outdoors
during a cold winter day.
14. What are the trade winds, and where do they occur?
15. What are jet streams?
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Day 7 - watch video on teachers domain :
Arctic Climate System Name ____________________
Earth's climate is maintained by the continuous cycling of energy through the planet's various systems. The oceans,
air, land, and living things are all interconnected as a single integrated system. Because solar radiation strikes
Earth's surface at varying angles from north to south, the planet is heated unevenly, and areas near the equator
are heated more intensely than at the poles. The resulting temperature differences drive global circulation patterns
as heat flows from warmer to cooler regions. In the atmosphere, warmer, less dense air rises as colder, denser air
sinks, creating convection currents. The movement of air masses and Earth's rotation create air circulation cells and
zones where winds blow in characteristic patterns. In the oceans, heat is redistributed around the planet via tides
and ocean currents, which result from wind acting on the surface of the water and from density differences
resulting from variations in temperature and salinity.
Ocean surface currents resemble global wind patterns; for instance, at mid-latitudes, both wind and ocean currents
tend to blow from west to east. In the North Pacific Ocean, the North Pacific Current flows eastward until it splits
into two circulation cells, or gyres: the California Current circulates down the coast of California to bring relatively
cool water toward the equator and the Alaska Current circulates relatively warm water up the coast of Canada and
Alaska. Thermohaline circulation, also known as the Great Ocean Conveyor belt, is a global circulation pattern that
connects both surface and deep water currents. It results from differences in water temperature and density and is
driven by the cold, salty water formed in the polar regions. Cold water is denser than warmer water, and the
formation of sea ice leaves behind salt, further increasing the salinity and density of the water. The dense water
sinks and flows along the ocean floor, driving thermohaline circulation.
In recent years, there have been noticeable changes in Earth's climate as average temperatures have increased.
Climate change effects are particularly evident in the Arctic, where the snow- and ice-covered landscape is
especially sensitive to change. For example, warmer temperatures have caused changes in the extent of snow and
ice cover. While the effects of these changes have a direct impact on the people of the region (such as subsistence
hunters who depend on the sea ice for hunting), changes in the Arctic might also create repercussions throughout
the Earth system. For instance, a decrease in the formation of sea ice could modify thermohaline circulation as well
as increase the amount of solar radiation that Earth's surface absorbs (because of the lower albedo of water
compared to ice). This, in turn, could create a positive feedback loop that would exacerbate global warming.
Scientists do not know the speed, size, and full effects of climate change, although most scientists agree that there
will be profound effects on the planet.
1. What is meant by the term "system" in science? Can you think of a small system close to home? How does this
system compare and contrast to global systems referred to in this video?
2. What are some changes that have been observed in Alaska that will have repercussions throughout the Earth
system?
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3. How could warming in the Arctic affect oceanic circulation?
4. Research the currents that surround the Northern Arctic. How could the change in these currents affect the
ecosystem balance, the spread of nutrients, and the life cycle of sea creatures?
5. If carbon dioxide and methane from Arctic permafrost and methane hydrate layers were rapidly released into
the environment, what would be the effect on climate?
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watch video on teachers domain : Earth as a System
Understanding our planet as an integrated system of components and processes is a fundamental part of Earth and
space science research. Just as the human body is composed of interrelated systems that control specific bodily
functions, Earth's four principal components — the atmosphere (air), lithosphere (land), hydrosphere (water), and
biosphere (life) — perform critical roles that, together, support and sustain life on the planet.Nothing influences the
subsystems that contribute to Earth's dynamic behavior more than heat. Heat comes from two sources: solar
energy and radioactivity in the Earth's core. Because of the angle at which the Sun strikes Earth, Earth's surface is
heated unevenly. This creates Earth's three major climate zones — tropical, temperate, and polar — which then
influence what types of life flourish in different locations.The uneven heating also controls weather systems. The
heat absorbed by the oceans and carried by its currents is constantly being released into the atmosphere. This heat
and moisture drive atmospheric circulation and set weather patterns in motion. The weather patterns then influence
vegetation, as well as erosion and sediment transport.
The other heat source, deep within Earth's core, is responsible for plate tectonics, which gives the Earth its physical
character: mountain ranges and valleys, ocean basins and lake beds, and islands and trenches. The heat from
Earth's core generates convection cells within its mantle, which help drive plate activity.
Ever since the first photos were sent back from space, our view of Earth has changed. Remote sensing instruments,
such as satellites, allow us to better understand the interrelationships between the different subsystems. For
instance, recordings made by remote and Earth-based instruments show that significant surface warming has
occurred over the past three decades. Knowing this, scientists are working to determine how this will affect — and
already is affecting — the entire Earth system.
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1. What are the many interacting Earth systems you can describe from this video?
2. Choose two Earth systems and describe the ways in which they interact.
3. What are your thoughts on the impact of humans on our planet after seeing the satellite images of Earth?
4. How has remote sensing changed our ability to study the Earth and how has it contributed to global
monitoring of the planet?
5. Think of one environmental issue and explain how global monitoring would be beneficial to gaining
knowledge of its impact on the Earth.
watch video on teachers domain : Climate Change
Environmental conditions are constantly in flux. Many of these changes may escape our notice: Temperatures rise
and fall throughout the day, humidity and air pressure fluctuate, and clouds form and dissipate. However, these
same variables can combine to create phenomena that are readily observable, such as wind, rain, snow, and
thunderstorms. These relatively short-term environmental changes, which might occur over periods of hours, days,
weeks, or seasons, are collectively referred to as weather.
Climate describes environmental conditions over much longer periods of time than weather forecasts and reports.
These long-term environmental analyses characterize a specific geographic location's temperature and precipitation
averages and ranges. Anomalous high and low readings are absorbed by these averages, resulting in a reliable
estimate of expected normal conditions.
Indeed, the global climate is, by definition, more stable than local weather. But climate is also constantly changing.
In fact, research conducted over the last 20 years or so describes dramatic shifts in climate in Earth's distant past.
These shifts occurred over a period of a decade or less, rather than over thousands of years as scientists once
thought was necessary.
Scientists began studying evidence of climate change, especially the role of ice ages in Earth's geologic history,
more than a century ago. During the most recent ice age, the Pleistocene, average global temperatures were about
5°C or more below present temperatures. This and other ice ages detected in the geological record were set in
motion by gradual changes in the Earth's tilt, rotation, and orbit over thousands of years. Despite the gradual
nature of these changes, Earth's climate appears to respond rapidly once certain boundary conditions are set in
place.
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Layers of ice analyzed from Greenland ice cores provide a chronology detailing the rapid onset of ice age
conditions. They show average continental surface temperatures rising and falling dramatically in just a few years,
rather than over the course of hundreds or thousands. For example, between 43,000 BC and 8,000 BC, average
global temperatures fluctuated periodically by as much as 20°C (36°F) or more. In contrast, climate changes since
8,000 BC have been characterized by temperature shifts of just 4°C (7°F) or less.
Many climatologists think these events resulted from changes in heat energy transfer by ocean currents from the
tropics to the higher latitudes, caused by a decrease in salinity. For example, computer models suggest that around
13,000 years ago, the Gulf Stream waters, which warm northwestern Europe, might have been altered or halted
dramatically by influxes of fresh water from melting glaciers. However, scientists do not understand the specifics of
how a decrease in the rate of energy transfer by the ocean currents from the tropics to the higher latitudes
translates to changes in regional and global climate.
1.
Explain the relationship between climate and weather using examples from the video.
2.
Explain why floods, hurricanes, and tornadoes are aspects of weather, not climate.
3.
The video points out how dramatic climate changes have been in the past. Do we know the possible
triggers of these rapid shifts? Is it possible that we may experience one of these dramatic shifts in our
lifetime?
4.
The graph of average temperatures shows that today's temperatures are higher than they were 10,000 to
40,000 years ago. It also shows that today's temperatures have been dropping in the past centuries.
However, what doesn't show on this graph is that temperatures have been increasing over the past several
decades. What do most scientists believe is contributing to this increase in temperature?
5.
Can you think of other possible ways scientists can determine what climate was like in the past besides
studying ice cores?
37
-
Earth’s Albedo and Global Warming
Different features of Earth (such as snow, ice, land, ocean, and clouds) have different albedos—the percentage of
solar radiation reflected back into space. For example, land and ocean have low albedos (typically about 10 to 40
percent is reflected back into space) and absorb more energy than they reflect, while snow, ice, and clouds have
high albedos (typically 70 to 90 percent) and reflect more energy than they absorb. Overall, Earth's average albedo
is about 30 percent; in other words, about 30 percent of incoming solar radiation is reflected back into space, and
70 percent is absorbed.
Earth's radiation budget is a concept that helps us understand how much energy Earth receives from the Sun, and
how much energy Earth radiates back to outer space. Depending on the balance, Earth may be experiencing a net
warming or a net cooling. Over the past century, there has been a net warming, which has caused Earth's
temperature to increase by about 0.8°C.
An increase in global temperature causes snow and ice to melt, which decreases the extent to which they cover the
surface, which then decreases Earth's albedo. This decrease in albedo means more energy is absorbed, which
causes further warming and in turn causes more melting. This ice-albedo positive feedback loop accelerates change
in global temperature and is, therefore, a critical concept to understand when trying to predict global climate
change.
Human activities that create pollution influence the energy balance. For example, when we burn coal, oil, wood,
and other fuels, the carbon by-product, soot, is released into the atmosphere and eventually deposited back on
Earth. The dark particles land on snow and ice, and decrease albedo. Wearing a black shirt (which absorbs
radiation) on a sunny day will make you feel warmer than if you wore a white shirt (which reflects radiation).
Similarly, the darkened snow and ice absorb more radiation than pure snow and ice. In addition, as the snow and
ice melt, the soot embedded in the snow is left behind and becomes more concentrated on the surface, further
accelerating warming.
Aerosols (tiny particles in the air) also alter the amount of radiation absorbed and reflected by the atmosphere.
Some aerosols, such as soot, absorb radiation; they have a warming effect. However, light-colored aerosols, such
as sulfates, increase the amount of solar radiation that is reflected; they have a cooling effect. Currently there is a
partial balance between dark and light aerosols, but their overall effect is similar to what happens after a large
volcanic eruption: particles in the air reduce the amount of solar energy that reaches Earth's surface. This effect,
known as global dimming, appears to have been masking the full impact of global warming. In the 1990s, as efforts
to decrease the amount of air pollution reduced the particulates in the air, studies showed an increase in solar
radiation. Ironically, reduced particulate emissions may cause Earth's temperature to rise faster than many earlier
models predicted.
1. What is meant by the term albedo? How does albedo affect the behavior of solar radiation reaching Earth's
surface?
2. Why would you expect Greenland to have a higher albedo than its surrounding areas?
3. What role would seasonality have on Earth's albedo and how does the Earth's albedo change over the
course of a year?
4. How do soot particles in the atmosphere affect incoming solar radiation? How might an increase or
decrease in the number of particles change the intensity of solar radiation reaching Earth's surface?
38
Global Warming and the Greenhouse Effect
There was once a great debate about whether or not the Earth is warming, but the evidence now has scientists
convinced. Since the start of the Industrial Revolution in 1880, the average temperature of the planet has increased
by just over one degree Fahrenheit, currently standing around 60°F. This seemingly insignificant change represents
a fairly rapid warming trend. According to the UN-sanctioned Intergovernmental Panel on Climate Change (IPCC),
the Earth's inhabitants will be facing temperatures at least three, and as much as ten, degrees warmer by the end
of the twenty-first century.
To put this into perspective, consider the temperature difference between now and the last ice age (about twenty
thousand years ago): nine degrees Fahrenheit. If the IPCC's predictions hold, that same temperature change will
happen within the next one hundred to three hundred years. Natural cycles of warming and cooling usually take
tens of thousands of years, not hundreds. So what's going on?
To understand global warming, you must first understand why our planet is warm in the first place. The Earth's
surface warmth is due to an atmospheric process called the greenhouse effect. In the blanket of molecules (solids,
liquids, and gases) that forms our atmosphere, certain gases are responsible for warming the planet. These gases
act much like the glass of a greenhouse, letting sunlight in while preventing heat from escaping, and for this reason
they are called greenhouse gases. The most important (and naturally occurring) greenhouse gases are water vapor
(H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). For most of the Earth's 4.6-billion-year
history, greenhouse gas concentrations (and temperatures) have followed a complex pattern of ups and downs, as
the Earth cycled through warm periods and ice ages. But for the past nine thousand years, temperatures have been
unusually stable. Some scientists believe this stability was essential to the development of human civilization.
But since the Industrial Revolution, human activities have sent more and more greenhouse gases into the
atmosphere. Burning wood and fossil fuel (gas, coal, and oil) adds carbon dioxide; livestock and coal production
add methane; and agricultural and industrial processes add nitrous oxide. In addition, manmade CFCs and related
compounds, once widely used as propellants and refrigerants, have also contaminated the atmosphere. (In a
separate and unrelated process, CFCs destroy ozone, a critical atmospheric gas that filters out ultraviolet [UV]
radiation.) Fortunately, CFCs are no longer produced by the industrialized world.
Oceans and land plants can absorb only half of the excess greenhouse gases; the rest accumulates in the
atmosphere, where it strengthens the greenhouse effect and may cause climate instability. The National Academy
of Sciences just reported that the addition of greenhouse gases and other pollutants to the atmosphere can cause
abrupt, severe climate changes. Case in point: El Niño events are becoming more frequent and more severe.
Scientists can't predict all the consequences of increasing greenhouse gas concentrations in the atmosphere, but
they've got their eyes on the sky and will be watching closely for changes.
1.
What are "greenhouse gases" and from where do they come?
2.
What is the relationship between greenhouse gases and global warming?
3.
Compare and contrast Venus, Earth, and Mars with respect to their atmospheres and their surface
temperatures.
4.
How are greenhouse gases like the windows of a car?
39
Greenland Ice Sheet Project 2: A Record of Climate Change
Global warming and the role human activities play in climate change are often in the news. It is well established
that Earth's average temperature has risen about one degree Fahrenheit since the early 1900s, a century in which
atmospheric CO2 concentrations also rose. This trend is startling to many climatologists. Any role humans may be
playing in any alteration of a global system would be unprecedented and could carry unpredictable consequences.
However, determining the extent of the relationship between human activities and recent climate change presents
a difficult challenge -- certainly one requiring more than the 100 years of written data that are available to us.To
assess the significance of the past century's data, scientists are exploring records of Earth's climate that extend
much further back in time than any written histories. This evidence comes from a variety of sources, including tree
rings, deep-sea and lake sediments, and perhaps most importantly, ice cores.Scientists obtain ice cores by boring
into glaciers and polar ice sheets using hollow drill bits. The largest such operations have produced a series of short
cylinders of ice with a total length of more than 3,000 meters (9,840 feet). Cores taken from ice sheets in
Antarctica and Greenland provide a record of Earth's climate extending nearly 800,000 years into the past.Ice is
particularly important in climate research because it encapsulates components of the atmosphere that existed when
the ice was formed. Snow falling on top of a glacier traps dust particles, chemicals, and the air itself within and
between its crystals. As layers are added, the snow is compressed into ice and the evidence is locked inside.
Scientists unlock this evidence when they remove the ice cores. For example, scientists can determine temperature
by analyzing the ratio of different forms, or isotopes, of oxygen atoms in the core. By analyzing tiny air bubbles
trapped in a layer of ice, they can also determine the composition of the atmosphere when the layer was
formed.What seems clear from ice core analyses is that Earth's climate has varied significantly over time. Over the
course of the past 800,000 years, our planet has seen eight 90,000-year ice ages interspersed with 10,000-year
warm periods. In addition, scientists have found a direct correlation between global temperatures and greenhouse
gas concentrations, lending support to the observations made in the last century. What's more, in 2004, scientists
studying an ice core taken from Antarctica concluded that current CO 2 concentrations are higher than they have
been in 440,000 years, an observation with significant implications for understanding future climate change.
1.
What was involved in the drilling process and evaluation of the ice core segments?
2.
Why do you think the thickness of the ice from 0 to 110,000 years ago is not proportional to the thickness
of the ice from 110,000 to 250,000 years ago? What is the general trend in thickness of the ice layers with
increasing depth?
3.
What was the coldest temperature during the time period studied? How many degrees change was there
between the coldest temperature and the median present day temperature?
4.
Did the temperature change slowly or quickly during this time period? How fast was the fastest
temperature change and how many degrees of change were there?
5.
What do you think it would be like to live on the Greenland Ice Sheet and drill ice cores? What are five
things you would you bring with you?
40
Polar Bears and Climate Change
Climate is a crucial factor not only in determining where plants, animals, and microorganisms live and reproduce,
but also in understanding the types of ecosystems they form. The scientific community agrees that human-induced
warming, which is occurring, has the potential to trigger rapid changes, and that those changes will alter every
ecosystem on Earth in some way. For many species, such as the corals that inhabit tropical reef systems, climate
change is proving deadly. For others, including destructive insects like spruce budworms, climate change is leading
to favorable conditions that will allow their numbers to multiply.
The impact of climate change on the two polar regions is expected to be among the greatest of any on Earth. One
Arctic inhabitant, the polar bear, has become a symbol of the effects that global warming is increasingly having
around the world. This animal—the largest terrestrial carnivore—has become vulnerable because its primary
habitat, the Arctic ice, is shrinking.
Although they are excellent swimmers, capable of spending several hours at a time in icy waters, polar bears also
hunt, breed, den, and rest on top of the ice that covers the Arctic seas most of the year. The distribution of polar
bears is influenced by the type and distribution of sea ice, as well as the density and distribution of their food
sources.
Polar bears prey on seals and belugas, a species of whales. In doing so they also indirectly benefit other organisms
that these animals prey on—such as krill, the small crustaceans that are the foundation of marine food chains, and
smaller fish. Because polar bears have a disproportionate effect on their environment, they are considered to be a
"keystone" species in the Arctic ecosystem. Therefore, continued shrinkage in sea ice due to climate change will
have severe repercussions on life in the Arctic that will ripple through the entire food web.
The Arctic warming trend has already resulted in a three percent decrease per decade in the extent of sea ice since
the 1970s. A polar bear's access to food is critical for maintaining its body condition and ensuring its reproductive
success. During the ice-free season, polar bears must fast for as long as four months. If climate change shortens
the period of ice cover, bears may be forced on shore to rely on stored fat for even longer. With less available food,
reproduction rates will fall. Bear cubs will be smaller, so mortality rates will rise.
1.
How do scientists study the effects of global warming on southern Arctic polar bears?
2.
In what ways does radio tracking help scientists understand the behavior of polar bear populations and the
impact of changing environmental conditions?
3.
What are some visible effects of rising temperatures in the Arctic?
4.
How are these changes affecting the polar bears?
5.
In what ways, if at all, do you think polar bears might be able to adapt to changing conditions in the Arctic?
41
The Anthropogenic Greenhouse Effect
Anthropogenic – relating to or resulting from the influence of humans on nature
The four main greenhouse gases are water vapour, carbon dioxide,methane, and nitrous oxide. Global warming
potential is a measure of the ability of a gas to trap thermal energy in the atmosphere over a specified time.
Persistence is the length of time the gas remains in the atmosphere. Gases that persist longer can absorb
thermal energy over a longer period of time.
- evidence of natural climate change and climate change influenced by human activity :
1.
4.
lake cores
ice cores
2.
tree rings
3.
fossils and preserved organisms
Tree rings (pg 622) Thicker rings mean the tree grew in better conditions — enough precipitation and
appropriate temperatures. Thin rings mean poorer conditions: drought, or higher or lower
temperatures than usual. By comparing the rings, scientists can determine the weather conditions
over the life of the tree
Science.gc.ca Ice Cores
Day 8 Climate and Tree Growth
For every year of its growth, a tree produces a single ring of new wood in its trunk. The width of each growth ring
is affected by the average temperature and moisture conditions during that year.
Since trees can live many years, tree rings can be used to identify changes in the climatic conditions of a local area
over long spans of time. In order to seethe growth rings, scientists drill out core samples that extend from the
centre of the tree (the pith) to the outer bark.
Sometimes, scientists are presented with data that need to be interpreted. When looking at the thickness of rings
on tree bark, scientists have to decide what constitutes “narrower” and “thicker.”
Purpose
To determine how tree rings are used to identify climate conditions
Materials & Equipment
 pen and paper
 ruler
Figure 8.4
Procedure
1.
Look at Figure 8.4. The tree in this sample is 10 years old because there are 10 rings between the bark and
the pith. Look at the thickness of each ring, and judge it to be “narrower” or “wider.”
2.
Create a chart with the following column headings: Sample, Age, Good Conditions, Poor Conditions, and
Notes.
3.
Look at the drawings of core samples taken at different times from four different trees growing in the same
area (Figure 8.5). Determine the age of each tree, and record it in your chart.
4.
For each core sample, interpret the time periods when each tree experienced good conditions and when each
experienced poor conditions. Record your interpretations in your chart.
42
Figure 8.5
Sample
Age
Good conditions
Poor conditions
Questions
5.
Write a descriptive sentence or two about each sample tree based on your data.
6.
Compare your interpretations with those of a classmate. How do they compare?
7.
Why would scientists studying climate change find the data from core samples useful?
8.
What are the advantages and limitations of this technique?
Pg 624 (3,6,8,9)
43
GREENHOUSE EFFECT(PG 625)
NAME __________________________
Objective: To describe how the “greenhouse effect” affects temperature on the earth and to use evidence to
support whether the “greenhouse effect” is good or bad for the earth.
Introduction: Global warming is perhaps the “hottest” topic in today’s headlines. The cause of warming is usually
blamed on the “greenhouse effect” or “greenhouse gases.” The following simulation will allow you to first examine
how the “greenhouse effect” works in a greenhouse. You will then experiment with a simulation of the earth’s
atmosphere where the concentration of greenhouse gases can be varied. Finally, you will use the results of the two
simulations to describe how the “greenhouse effect” affects temperature on the earth and discuss whether the
“greenhouse effect” is good or bad for the earth.
Directions: Steps in bold font require a written response. A double asterisk is placed in front of questions requiring
a complete response.
Before diving into the whole issue of global warming, try to picture sitting in an enclosed car on a cold but sunny
day … pretty comfortable, isn’t it. Now imagine sitting in that same car on a hot, sunny day. Don’t hold that image
too long. You’ll fry just thinking about it.
1) **Hypothesize why the inside of a car feels so much warmer than its surroundings on sunny
days.
2) Go to è
3) Select the “Heat and Thermo” tab.
4) Select the “Greenhouse Effect” simulation.
Or go to http://phet.colorado.edu/new/simulations/sims.php?sim=The_Greenhouse_Effect
Part I: A Greenhouse Simulation
5) Select the “Glass Layers” tab.
6) Uncheck the “View all photons” box.
7) What do the yellow stars represent? ___________________________
8) What do the red stars represent? ___________________________________
9) Both the yellow and red stars represent forms of energy in the form of photons: the yellow are visible
light, the red are heat.
a. Record the approximate temperature “inside the greenhouse” before adding glass
panes. _____________________________
10) Add one glass pane. ____________________________
11) **What do the sunlight photons do when they hit the glass from the top?
__________________________________________________________________
**What do the infrared photons do when they hit the glass from the bottom? Be specific.
___________________________________________________________________
12) What is the new temperature “inside the greenhouse?” _________________
**Based on the observations of the photons, why does the temperature go up so much?
13) What happens to the temperature as additional glass panes are added?
____________________________________________________________________
14) **Explain why this happens by observing the photons.
__________________________________________________________________________
__________________________________________________________________________
44
15) **Before proceeding to the earth, predict how what you have discovered regarding
greenhouses might apply to the earth and its atmosphere.
__________________________________________________________________________________________
__________________________________________________________________________________________
Part II: The Earth Simulation
16) Select the “Greenhouse Effect” tab.
17) Uncheck the “View all photons” box.
18) Which greenhouse gases are considered by the simulation? _______________________
19) Which time period do the default conditions represent? __________________________
20) The thermometer represents the average global temperature.
21) What is the average global temperature for the “today” simulation? __________________
22) Is the behavior of the photons more similar to the greenhouse simulation with or without
glass panes? ________________________________________________________
23) Reduce the greenhouse gas concentration to “None”.
24) Is the behavior of the photons more similar to the greenhouse simulation with or without
glass panes? ____________________________________________________________
25) What is the average global temperature? ___________________________________
26) **Considering the behavior of the photons, why does the temperature drop so much?
_____________________________________________________________________
27) Increase the greenhouse gas concentrations to “Lots.”
28) What is the average global temperature? __________
29) **Considering the behavior of the photons, why does the temperature increase?
_____________________________________________________________________
30) Experiment with other periods in earth’s history or add clouds and record interesting observations.
Part III: THIS IS THE MOST IMPORTANT PART OF THE LAB!!
Write a paragraph that answers the following questions:
1. How does the “greenhouse effect” affect temperature on the earth?
2. How is the “greenhouse effect” similar to blankets on a bed?
3. Is the “greenhouse effect” good or bad for the earth?
YOU MUST USE EVIDENCE FROM YOUR OBSERVATIONS OF THE SIMULATION TO SUPPORT YOUR ANSWERS.
Your grade will be based on the amount of evidence you use and how effectively you use it.
45
Day 9 Greenhouse Gases, Global Warming,and Climate Change
Temperature data collected from around the world show that the global average temperature increased by
approximately 0.74°C between 1880 and 2008. The eight warmest years of this period have all occurred since
1998.
Combined with the natural greenhouse effect, the anthropogenic greenhouse effect has led to global warming,
the observed increase in Earth’s average annual temperature. Global warming is leading to climate change.
008Science.gc.ca
So far we have come to the conclusion that an increase in the levels of carbon dioxide in the atmosphere
accompanies a rise in global temperature. We are now going to look at some data from other greenhouse gases to
see if they have the same effect.
300
250
CO 2
2
200
0
-2
T
-4
700
-6
CH 4
600
500
400
300
0
50
100
Thousands of years bef ore present
150
Graphs obtained from Antarctic ice core records of local atmospheric temperature
and corresponding air concentrations of carbon dioxide and methane for the past 160,000 years
1.
As the air temperature increases, what happens to the amount of methane in the atmosphere?
2.
Using the data from the graph to support your answer, do you think the amount of methane in the
atmosphere could lead to global warming?
46
The following graphs show estimated historical concentrations of major greenhouse gases, over the last 250
years.
1800
Methane
1600
1400
1200
1000
800
600
1750
1800
1850
1900
Year
1950
2000
310
Nitrous oxide
300
290
280
1750
1800
1850
1900
Year
1950
2000
1850
1950
2000
0.3
CFC-11
0.2
0.1
0
1750
1800
1900
Year
Graphs showing estimates historical concentrations of major greenhouse gases,
over the last 250 years
3.
In which year did the level of methane in the atmosphere first start to increase?
4.
Describe what happened to the amount of methane in the atmosphere after 1950.
5.
When did CFC-11 start to build up in the atmosphere?
6. The amount of nitrous oxide in the atmosphere has steadily increased during the last 250 years. When did
the rate of increase suddenly change?
7. Do you think that any of the above gases could be linked to global warming? You must explain your
answer.
47
The amounts of greenhouse gases in the atmosphere have increased dramatically over the last fifty years. This is
mainly because of increased human population and activities, such as man-made chemicals and combustion.
380
380
Ke y
360
340
Ice core
measurements
360
6
South pole
340
4
Fossil CO 2
emissions
320
2
300
0
Mauna Loa
One hundred
year running
mean
320
280
1850
1900
Y ear
1950
2000
300
280
260
800
1000
1200
1400
Y ear
1600
1800
2000
The table below lists the main man-made sources of these gases. Greenhouse gases also occur naturally.
Greenhouse gas
Sources due to human activities
________________
Burning of fossil fuels
Deforestation
___________________
Bacteria in rice paddy fields
Released from natural gas and oil wells
Landfill – (getting rid of waste)
Domestic animals – mostly cattle
Coal mining
Biomass burning
______________________
Refrigerants
Aerosols
______________________
Fertilizers
Combustion of fuels in cars and power stations
Biomass burning
One of the big problems with greenhouse gases is that once they enter the atmosphere, it is a long time before
they leave. The table below shows how long each molecule of gas will stay in the atmosphere.
Atmospheric lifetime (years)
Carbon dioxide Methane
CFC-11
Nitrous oxide
50–200
65
150
10
Atmospheric lifetime of greenhouse gases
8.
Which greenhouse gas stays in the atmosphere for the shortest length of time?
9.
Which greenhouse gas is the hardest to get rid of?
48
Key Concept Review
1. Describe the process of using growth rings on trees to derive information about climate.
2. Why is water vapour, a greenhouse gas, not included in the global warming potential information?
3. What is the Greenland Ice Core Project? What type of information do scientists find when they analyze the ice
cores?
4. What is global warming potential?
5. List three greenhouse gases. Describe how the atmospheric concentration of these gases has changed over the
last 200 years.
6. Define the term “anthropogenic greenhouse effect.” Why is it important to distinguish it from the term “natural
greenhouse effect”?
7. List three human activities that contribute to climate change.
8. Compare the type of data derived from tree growth rings to that derived from the Greenland Ice Core Project.
9. What evidence have scientists cited as the reason for their conclusion that human activity is a major cause of the
increase in Earth’s observed global warming?
10. Describe the relationship between the anthropogenic greenhouse effect and climate change.
11. Is it possible that climate change could occur in only one part of the world? Explain.
12. Why might the terms “natural greenhouse effect” and “anthropogenic greenhouse effect” be useful even
though they are caused by the same gases?
49
EcoSchools Multimedia Presentation:
The Science of Climate Change
This student question sheet will help you make notes for the EcoSchools multimedia presentation,
The Science of Climate Change. Included in the presentation are video clips linked to specific slides
providing additional information about the science of climate change. Answers to the questions below
will be found in both the slides and the video clips.
Introduction Slides 1-16
1. What is climate?
2. What are the 5 main components of the global climate system?
3. Describe the greenhouse effect. Draw a diagram of the greenhouse effect.
4. What key outside factor affects the global climate system?
5. Complete this equation:
When energy in = energy out, we have _________________ climate system
6. Looking at the diagram on slide 14, in what form does energy reach the earth’s climate system?
In what forms does energy leave the earth’s climate system?
7. Describe the enhanced greenhouse effect. “Enhanced” is the word used to discuss human-created
climate change.
8. What are 3 major climatic responses to the enhanced greenhouse effect observed by IPCC scientists?
9. What happened to create the enhanced greenhouse effect and change the balance in the climate
system?
Carbon is crucial; Weathering the storm Slides 17 - 37
10. How is carbon released? What are the natural sources of carbon in the global climate system?
11. What are the natural sinks (absorbers) of carbon?
50
12. What is the main form of carbon linked to the enhanced greenhouse effect?
13. What human processes release carbon into the atmosphere at a rate faster than the natural
system can absorb?
14. What other human activities have contributed to the reduction in carbon absorption?
15. List the types of weather changes associated with climate change.
16. The density of seawater drives the flow of ocean currents. What 2 key physical characteristics
determine the density of seawater?
17. Why is thermohaline circulation important to the climate and ecosystems around the world?
18. What are some of the problems that plants and animals face with rapid changes in climate?
Science and Technology: Problems and Solutions Slides 38 – 56
19. What types of technology assist scientists in studying climate change?
20. List 3 emission-free energy sources.
21. List 3 transportation technologies that reduce the emission of greenhouse gases.
22. What is the Kyoto Protocol?
51
Independent research
Name ______________________________
Assess, on the basis of research, the effectiveness of some current individual, regional,national, or international
initiatives that addressthe issue of climate change (e.g., Drive Clean,ENERGY STAR, federal and provincial
government rebates for retrofitting older buildings to be more energy efficient, carbon offset programs,
community tree-planting programs, municipal recycling programs, Intergovernmental Panel on Climate Change
[IPCC]), and propose a further course of action related to one of these initiatives
Issue: Governments and industry have created rebates or tax cuts to encourage consumers to replace their old
appliances with efficient ENERGY STAR appliances. However, such initiatives do not take into account the resources
used to create the new products or the problems associated with the disposal of old appliances.
Questions: What type of recycling and composting programs are in place in your community?
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
What proportion of locally generated garbage do they divert from landfill sites?
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
How could they be improved?
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
What is the purpose of carbon offset credits? Do they achieve that purpose? Why or why not?
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
Assess, on the basis of research, the effectiveness of some current individual, regional, national, or international
initiatives that address the issue of climate change (e.g., Drive Clean,ENERGY STAR, federal and provincial
government rebates for retrofitting older buildings to be more energy efficient, carbon offset programs,community
tree-planting programs, municipal recycling programs, Intergovernmental Panel on Climate Change [IPCC]), and
propose a further course of action related to one of these initiatives.
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
52
53
54
55
Day 10 Effects of Climate Change in the Atmosphere
Heat Waves, Drought, Wildfires, Storms, Floods
Effects of Climate Change in the Hydrosphere
Melting Ice
As the average global temperature increases, Earth’s ice — both sea ice and glacier ice — is melting. This has
consequences for more than just the Arctic and Antarctic regions. Melting ice can affect Earth by:
• flooding land that is currently just above sea level
• changing habitats of shoreline plants, animals, and micro-organisms
• causing the loss of property
• changing geographic coastlines and shapes of continental coasts
• reducing the amount of fresh water available to communities
The average level of the world’s oceans has increased by about 20 cm over the past century. There are three
causes of this: as water warms, it expands; glaciers on land have retreated; and more recently, the Greenland and
Antarctic continental glaciers have been melting.
Ocean Warming
Over the past century, the average ocean temperature has increased by about 0.6°C
As the water warms, it expands, so warmer oceans mean higher sea levels, causing loss of coastal land. Warmer
water absorbs less carbon dioxide (just as cold pop retains more carbon dioxide than warm pop does), so it is less
effective as a carbon sink.
Warmer water is not as ideal a habitat for plankton growth. Phytoplankton undergo photosynthesis and therefore
are an
important carbon sink. Warmer oceans mean less phytoplankton, less carbon dioxide absorbed, and therefore an
increase in greenhouse gas emissions.
Warmer water produces more intense hurricanes, which damage land and harm people. Hurricanes are also
beneficial in that they transfer heat from the warm tropical oceans to colder climates.
Where Do You Stand?
Issue
Climate change, like every issue, has many interpretations. There is a very strong consensus among scientists on
most of the evidence. However, scientists, governments, environmental groups, and the general public can have
different opinions about how serious the issue is, how dire the consequences may be, and how much can be done
about it.
Background Information
It is a fact that the Earth’s average annual temperature has increased over the last century. Evidence from data
such as fossil records and ice cores shows how Earth’s climate has undergone many changes in the past, both
before and since humans existed. However, some people argue that today’s global warming could just be part of a
natural climate cycle that occurs over thousands of years. They believe that until such cycles are fully described,
the human contribution to global warming remains debatable.
The issue of climate change has prompted a great deal of discussion. The IPCC stated in 2007: “Warming of
the climate system is unequivocal, as is now evident from

observations of increases in global average air and ocean temperatures,

widespread melting of snow and ice, and

rising global average sea level.”
Climate change skeptics, on the other hand, make three main points.

We do not understand Earth’s climate well enough to make predictions about the future.

The global climate is getting warmer but not because of human activities.

The global climate is getting warmer, but this will create greater benefits than costs.
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Each group has access to the same evidence — the evidence (effects) described in this chapter — but has come
to different conclusions.
When you looked at the students’ marks in the previous activity, you may have determined that a student
should pass but were unsure about the exact grade. When you evaluate the evidence on climate change, can you
decide where you stand on this issue? Where would you rank the seriousness of the issue in terms of the other
issues facing us? What do you think you can or should do about the issue? What is your obligation to future
generations? What roles do the reports from the media and government play in forming your opinion?
Analyze and Evaluate
1.
Go to ScienceSource to begin your search for information.
2.
Look for a variety of different views about climate change. Make a fact sheet on three groups of people with
different views. Identify the qualifications and potential bias of the group/person.
3.
Using a ranking system of 1–5, with 1 = mildly serious to 5 = extremely serious, rank each group/person’s
views on
 how serious is climate change?
 how dire are the consequences?
4.
State how each group/person views what can and should be done about it.
5.
Think about what you know about climate change, and add your own views to the fact sheet.
6.
How do you think your view has been shaped by media, government views, and this unit?
7.
Discuss your views as a class. Do you hold similar or different views? What evidence do you agree on?
Where do your views differ?
Skill Practice
8.
What evidence are you using to support the way you filled out your fact sheet?
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Unit 4 Review
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Which of the following conditions is not used when describing weather?
a. today’s precipitation
c. air pressure change this week
b. current cloud cover
d. average temperature
____
2. Which of the following statements best describes climate?
a. the average precipitation falling in a region over a minimum of 3 years
b. the average temperature occurring in a region over a minimum of 30 years
c. the average weather conditions occurring in a region over a minimum of 3 years
d. the average weather conditions occurring in a region over a minimum of 30 years
____
3. The image shows two equal amounts of solar radiation striking Earth in two different locations.
Which of the following statements is true about locations A and B?
a. Area B receives more solar radiation per m2 because of a higher angle of incidence.
b. Area B receives more solar radiation per m2 because of a higher angle of incidence.
c. Area A receives more solar radiation per m2 because of a lower angle of incidence.
d. Area B receives more solar radiation per m2 because of a lower angle of incidence.
Layers of Earth’s Atmosphere
I. mesosphere
II. troposphere
III. thermosphere
IV. stratosphere
____
4. What is the correct order of atmosphere layers, from nearest to Earth to farthest away?
a. III, I, IV, II
c. I, II, III, IV
b. II, IV, I, III
d. II, I, IV, III
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____
5. Which set of data matches the
a.
J
F
M
mm
76.4 62.2 54.6
°C
-5.5
-5.8
-2
climatograph for London, Ontario?
A
58.1
5.1
M
67.6
11.2
J
71.8
16.9
J
70.5
19.7
A
63
18.9
S
79.6
15.4
O
78.3
9.4
N
79.1
2.8
D
77
-2.8
M
26.3
-8.2
A
33.9
3.3
M
54.7
11.2
J
81.1
16.7
J
73.8
19.6
A
65.5
18.2
S
54.5
12.3
O
35
5.4
N
26.4
-5.1
D
21.7
-14.1
M
55.8
12.3
J
47.1
15.1
J
31.3
17.3
A
37
17.1
O
116.3
10
N
154.6
5.9
D
171.5
3.7
b.
mm
°C
J
21.4
-18.6
F
19
-16
J
145.7
2.7
F
121.4
4.4
M
102.3
6.1
A
69.2
8.9
J
F
M
A
M
J
J
A
S
O
N
c.
mm
°C
S
59.6
14.3
d.
____
____
____
D
mm
6
13.4
36.5
109.6
166.3
614.3
817.5
549.9
243.8
200.4
21.4
16
°C
19.9
22
25.4
27.6
28.6
28.1
27.8
27.9
28.2
27.5
24.5
20.9
a. Table A
b. Table B
c. Table C
d. Table D
6. What month is the driest in London, Ontario, and how much precipitation falls during that month?
a. April is the driest, when 58.1 mm of precipitation falls.
b. April is the driest, when 54.6 mm of precipitation falls.
c. March is the driest, when 54.6 mm of precipitation falls.
d. March is the driest, when 58.1 mm of precipitation falls.
7. What is the main contributor to the natural greenhouse effect?
a. nitrous oxide
c. methane
b. water vapour
d. carbon dioxide
8. A kettle of water is placed on the stove. Heat is transferred through the water by what process?
a. radiation
c. conduction
b. absorption
d. convection
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____
9. The Coriolis effect causes moving air to turn in what direction(s)?
a. left in the northern hemisphere and right in the southern hemisphere
b. right in both the northern and southern hemispheres
c. left in both the northern and southern hemispheres
d. right in the northern hemisphere and left in the southern hemisphere
____ 10. What causes global wind patterns to behave as they do?
a. the Coriolis effect
b. convection currents in the hydrosphere
c. convection currents in the atmosphere
d. both a and c
____ 11. Without these global wind patterns, what would happen to Earth’s net radiation budget?
a. It would remain equal to zero, but the areas near the equator would get much warmer
and those near the poles would get much cooler.
b. It would remain equal to zero, but the areas near the equator would get much cooler and
those near the poles would get much warmer.
c. It would decrease, and the areas near the equator would get warmer and those near the
poles would get much cooler.
d. It would increase, and the areas near the equator would get much warmer and those near
the poles would get cooler.
____ 12. Most of Canada, including Ontario, is under the influence of what global wind pattern?
a. the polar easterlies
c. the northeast trade winds
b. the prevailing westerlies
d. the southeast trade winds
____ 13. Counting the rings on the cross section of a tree trunk reveals what?
a. the species of tree
b. the weather conditions when the tree first began to grow
c. the tree’s growing conditions
d. the tree’s age
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____ 14. Which of the following is the greenhouse gas that has the highest global warming potential over 100 years?
a. nitrogen
c. carbon dioxide
b. nitrous oxide
d. methane
____ 15. Why are glaciers excellent sources of climate data?
a. The ice moves throughout the world as water vapour before freezing.
b. The ice traps atmospheric gases in layers for thousands of years.
c. The ice preserves organisms so they do not decay.
d. The ice often collects particles as it floats in the oceans as icebergs.
____ 16. How does a glacial ice core reveal information to scientists?
a. Thick layer samples in the core reveal cold years.
b. Layer samples are melted and analyzed for climate conditions.
c. Layer samples are melted and analyzed for gas content.
d. Thick layer samples in the core reveal warm years.
____ 17. Why do the effects of climate change and global warming appear to be affecting the land more quickly than the
oceans?
a. Water has a high heat capacity.
b. The oceans are affected more than the land, but people do not live in the oceans so we
don’t notice.
c. Oceans are not affected by global warming.
d. There is more land than water on Earth.
Completion
Complete each statement.
18. The phrase _________________________ is used to describe a gradual, long-term change in Earth’s average
weather conditions.
19. Some of the solar energy from the Sun is absorbed by the surface of Earth, converting the solar energy into
____________________ energy.
20. The ____________________ layer of the atmosphere has ozone gas, which filters out harmful UV radiation from
the Sun.
21. The amount of insolation an area receives throughout the year depends mostly on its ____________________, also
known as the distance from the equator.
22. Snow reflects almost all of the solar radiation that hits it, so snow has a very high ____________________.
23. “Warm fluids rise, and cooler fluids flow under them to replace the fluid that has moved” describes the thermal
energy transfer called ____________________.
24. Cooler water tends to ____________________, while warmer water rises.
25. _________________________ are a simple, effective, and easy-to-find method of studying the local climate
conditions for the past 20–100 years.
26. _________________________ is the greenhouse gas with almost 300 times the warming potential of carbon
dioxide in the atmosphere.
27. The ____________________ greenhouse effect refers to human activities enhancing the normal balance of gases
and thermal energy transfer on Earth.
28. Coal mining, natural gas leaks, and landfills are human-related activities that release ____________________ into
the atmosphere.
29. The term _________________________ refers to the effects of global warming, resulting in more extreme weather
events and changing average temperatures and precipitation amounts.
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30. The effects of climate change have not been noticed in the oceans as much as on land because water
____________________ more slowly than land.
31. Warmer ocean water absorbs less _________________________ than cooler water, making warmer oceans a less
effective carbon sink.
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____ 32. Climate is influenced by how close an area is to a large body of water. ____________________
____ 33. Thermal energy is the total kinetic energy of all of the particles in a substance. ____________________
____ 34. The mesosphere is the atmospheric layer where weather occurs. ____________________
____ 35. Some solar radiation reaching Earth’s surface is absorbed and re-emitted into the atmosphere as infrared radiation,
which is then absorbed as thermal energy by greenhouse gases such as methane and carbon dioxide.
____________________
____ 36. The albedo of water, soil, and asphalt is very low compared to snow, ice, and dry grass. ____________________
____ 37. The trade winds blow from east to west along the equator. ____________________
____ 38. The greenhouse gas methane is usually not included in studies of climate change because its concentration
changes with temperature, and it is part of the hydrologic cycle. ____________________
____ 39. An ice core more than 3 km long from a Greenland glacier provides scientists with the ability to test the amount of
gases in the atmosphere for the past 200 000 years. ____________________
Short Answer
The Impacts of Climate Change on Ontario’s Forests
The length of the forest fire season is expected to increase with longer growing seasons. In addition, increased
moisture loss from forests due to elevated temperatures would increase forest fire frequency and severity. Forest
plant diseases and insects attack plants that have been stressed: increases in drought could also increase the
frequency of major insect and disease outbreaks. An increase in forest fires, insect outbreaks and diseases would,
in turn, alter the age structure and plant species in forest ecosystems, with the greatest impacts expected in
northwestern and southern Ontario. Extreme weather events, such as ice storms, floods, and very high or widely
fluctuating temperatures could further damage or stress plants.
Source: http://www.ene.gov.on.ca/envision/air/climatechange/impacts.htm
Ontario Forest Research Institute (OFRI)
40. List four of the primary effects of climate change on Ontario forests as outlined in this report.
41. What events could further stress and damage the forests after the initial effects of climate change have occurred?
42. How does the article suggest the contents of the forests could change as a result of these effects?
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Polar Bears and Climate Change
Ontario is home to the southern-most population of polar bears in the world. Climate change is
considered the greatest threat to the long-term survival of these bears. The Ontario Ministry of
Natural Resources and its partners are working together to help ensure the long-term survival of
Ontario’s polar bears.
The polar bear (Ursus maritimus) is Ontario’s largest carnivore and is an important component of
the Hudson and James Bay ecosystem of northern Ontario, northern Quebec and southern
Nunavut. It’s also of significant cultural importance to Aboriginal communities. The continued
presence of polar bears is a strong indicator of the health of this northern ecosystem.
Source: http://www.mnr.gov.on.ca/en/Business/SORR/2ColumnSubPage/263772.html
Ontario Ministry of Natural Resources
Follow MNR’s Hudson Bay polar bears with the online Polar Bear Tracker
(http://polarbears.wwf.ca/tracker.html)
In the fall of 2008 MNR researchers collared 13 polar bears with GPS
satellite radio collars along the coasts of James Bay and Hudson
Bay. With the collars picking up six GPS locations daily for each bear,
researchers can track where the bears are headed with incredible
accuracy. This will help them to identify bear movement patterns, as
well as how ice conditions will affect survival rates and population
abundance.
Now everyone can check out what is happening with three of the
MNR collared polar bears through the online Polar Bear Tracker. In
partnership with WWF for the second year, the tracking tool allows
you to view the movements of “Truth”, “Harmony” & “Copenhagen”
through the WWF website.
A polar bear is sedated in
preparation for a GPS.
Source: http://www.mnr.gov.on.ca/en/Business/SORR/2ColumnSubPage/263772.html
Ontario Ministry of Natural Resources
43. How might the Ontario polar bears reveal the health of northern ecosystems? How would polar bears moving
around more than usual reveal a weakening ecosystem?
44. List three reasons mentioned in the first article for having the polar bears remain healthy and successful in this
area.
45. How can tracking polar bears help to determine ice conditions in James Bay and Hudson Bay?
46. Why do you think it is important to allow normal people to see the tracked polar bears on the Polar Bear Tracker
website?
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Problem
47. Compare and contrast the climatographs of London and Thunder Bay.
48. Describe how a moderate climate differs from a severe climate and how these differences might affect the
economy, the food supply, the type of shelter, and a person’s choice of clothing.
49. Explain how the angle of incidence of solar radiation influences climate.
50. Describe what is being shown in the illustration below, and what the illustration reveals about the living conditions
in this location.
51. What do locations that are at the same latitude have in common? Discuss two reasons for studying climate in
different areas of the world that are at the same latitude.
52. Compare and contrast conduction and convection as they relate to climate.
53. Describe how the specific heat capacity of water influences climate in coastal and non-coastal regions. Why would
people want to live in these areas?
54. Describe the factors that create Earth’s global wind and ocean currents.
55. Describe the natural greenhouse effect. Why is the word “natural” used for this effect?
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Matching
Match each thermal energy term with the description below. Use each letter only once.
a. Coriolis effect
b. surface ocean currents
c. wind
d. westerlies
e. jet stream
____ 56. the movement of cool air from an area of high pressure to an area of low pressure
____ 57. the deflection of an object from a straight line path by the rotation of Earth
____ 58. winds that blow across the surface of Canada
____ 59. a band of fast-moving air in the stratosphere
____ 60.
face