Grade 5

Grade 5
Objective
Students will be able to:
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Describe the technological advances that allow scientists to deepen their understanding of the
effects of global warming by studying components of the air,
Define what greenhouse gases are,
Explain how these gases contribute to the greenhouse effect,
Describe global warming and its effects, and
Learn what management strategies farmers can choose to reduce their contribution to the
global atmosphere through greenhouse gas emissions.
Key Concepts
Introduce children to the concept of greenhouse gases. What are they? What are they made up of?
What effect do they have on the climate? How are they harmful to the Earth? What can we do to
decrease our contribution to the emission of greenhouse gases? What kinds of things do farmers need
to consider in order to reduce their contribution to total greenhouse gas emissions? How are farmers
able to increase their uptake of greenhouse gases?
Cluster 4: Weather
5-4-12 Describe examples of technological advances that have enabled humans to deepen their
scientific understanding of weather and improve the accuracy of weather predictions. Examples:
satellites collect data that scientists analyze to increase understanding of global weather patterns
(Connection: Scientists even study the components of the air including CO2 concentration and other gas
concentrations, with analyzers and several other instruments)
Scientists can study components of the air. Greenhouse gases are important components of the air for
scientists to measure especially when it comes to learning and wanting to know about weather/climate
changes.
Example: How are they able to measure carbon dioxide (CO2) levels in the air?
By using a CO2 analyzer! Come out to the Discovery Center to participate in activities and see how a CO2
analyzer works!
Apart from analyzing what is already present in the air, scientists are also coming up with technologies
to help control and limit the amount of greenhouse gases in the atmosphere. This will help to protect
human health as well as our ecological resources. Resources in advanced energy production, waste-to-
energy conservation, oil and gas production, transmission and other energy efficiency technologies are
just a few examples.
5-4-13 Explain how the transfer of energy from the Sun affects weather conditions. Include: Sun’s
energy evaporates and warms the land, water and air daily
(Connection: Investigate why the Earth stays warm- the greenhouse effect and how it is both natural and
influenced by humans; especially with increased CO2 levels)
What are greenhouse gases? A greenhouse gas is a gas that is present in the Earth’s atmosphere. It traps
thermal radiation (heat) from the Earth inside the atmosphere, warming up the Earth. For example,
water vapour is a very important greenhouse gas. But there are three other greenhouse gases which
can occur naturally or be affected by human activities:
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Carbon Dioxide (
): a greenhouse gas that occurs naturally and is also released by human
activities. The Earth only can take up half of the carbon dioxide that is produced by humans.
Fires, burning fossil fuels, and making cement are examples of the things that produce carbon
dioxide.
Methane (
): is a greenhouse gas and is a component of natural gas. Major contributors to
the production of methane are from cattle as well as landfills. Other sources of methane include
wetlands, organic decay, termites, natural gas and oil extraction, biomass burning, and rice
cultivation.
Nitrous Oxide (
): is a greenhouse gas produced naturally in the soil during the microbial
processes where the soil gains nitrogen and loses nitrogen. This gas has a tremendous ability to
trap heat in the atmosphere. Forests, grasslands, oceans, soils, soil cultivation, fertilizers,
biomass burning and burning of fossil fuels are also sources of nitrous oxide.
Why do they call it the “greenhouse effect”? A glass greenhouse lets in sunlight (solar radiation), which
warms the soil and plants in the greenhouse. This warm surface emits thermal radiation, but it is
trapped by the glass and can’t escape. This keeps the greenhouse warm. In the Earth’s atmosphere,
certain gases also trap thermal energy emitted by the Earth, keeping the Earth warm. We call these
“greenhouse gases”.
Without this natural greenhouse effect, the Earth would be much colder than it is now. The natural
greenhouse effect keeps the average surface temperature of the Earth at 15°C. Without the greenhouse
effect the temperature would be –18°C. That is about 33°C colder! The warmth of our climate is crucial.
Can you think of why? Because water can exist in three phases: solid (ice), liquid (water), or gas (water
vapour). The greenhouse effect is important for this reason.
But what has happened over the last 200 years? We seem to be experiencing an enhanced greenhouse
effect. Can greenhouse gases be causing harm?
5-4-18 Recognize that climates around the world are ever changing and identify possible
explanations. Ex. volcanic eruptions, ozone depletion, GH effect...
(Connection: What gases are present in the atmosphere and what influence do each of them havepositive/negative; look at how greenhouse gases (CO2 levels) are influencing the mean temperatures in
countries around the world and how some of these increases are being offset)
Greenhouse gases cause the heat from the Earth to be trapped within the Earth’s atmosphere. For this
reason, the temperature of the Earth is dependent on the concentration of greenhouse gases in the
atmosphere. When the concentration of greenhouse gases in the atmosphere rises, so does the
temperature of the Earth.
Because of the amount of greenhouse gases that have been produced by humans over the last few
hundred years, it is agreed that global warming is being caused by human activity. The man-made
greenhouse gas increases are causing the current average temperature increases.
The Intergovernmental Panel on Climate Change (IPCC) estimates that the Earth has already warmed by
about 0.6°C since 1850. And it is likely to warm by 1 to 2°C more by the year 2050. This warming will be
greater at higher latitudes (like Canada), but there will likely be a greater impact nearer the Equator
where it is already warm.
There could be many possible effects. For example, warming may lead to increased wildfires and
changes in seasonal periodicity. As well as, changes to grasslands and water supplies will affect the
grazing and welfare of domestic livestock. Increased warming will also have an effect on countries
whose climates are already near or at a temperature limit over which yields reduce or crops fail. Deaths
attributable to heat-waves, loss of polar bear habitat, increased mobile ice hazards to shipping, ocean
acidification, melting of glaciers, sea level rise, contamination or exhaustion of fresh water, increased
incidence of natural fires, droughts, increased risk of coral extinction, changes in migration patterns of
birds and animals, changes in seasonal periodicity, and disruption to food chains and species loss are all
examples of what could happen as a result of global warming.
In order to effectively address global warming, we must significantly reduce the amount of greenhouse
gas emissions we are currently releasing into the atmosphere. We all play a part in contributing to
greenhouse gas emissions. What can you do to help?
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Use energy efficient products
Develop renewable technologies – utilize renewable energy sources
Switch to low-carbon fuels
Ride your bike to school
Farmers have been playing their part in the control of greenhouse gas emissions too! They have to take
many things into consideration including their contribution to the global atmosphere through
greenhouse gases. They have considered the ways in which they can reduce their greenhouse gas
emissions and increase their uptake through various management strategies.
For example, animals that eat grass, like cattle, bison, deer, and sheep emit methane from their
stomachs. This is a natural process. Farmers can reduce this methane by feeding animals more grain or
searching for breeds that naturally emit less methane. Greenhouse gases can also be emitted from
manure, and researchers are looking at ways to manage this manure to decrease these emissions.
Growing crops also affects that amount of greenhouse gases in the atmosphere. For example, farmers
could consider:
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The type and timing of fertilizer use, because it affects emissions of nitrous oxide,
The type of crop: legumes like peas and soybeans have nodules that can take up nitrogen from
the atmosphere so they emit less nitrous oxide,
Using perennial crops instead of annual crops to store more carbon in the soil.
Other parts of the farming operation should also be considered, such as reducing the use of fossil fuels
by using equipment less, or perhaps using a biofuel. Some farmers also use equipment that can turn
organic matter like manure into natural gas for energy!
Now you know how farmers play their part in lowering greenhouse gas emissions, which is good for the
environment!