This presentation was assembled as part of the outreach initiative for the Canadian Network for the Detection of Atmospheric Change.

Transcription

1 This will be a lesson for students in grades The subject matter is climate change - the greenhouse effect, greenhouse gases, how greenhouse gases are measured and studied, and the impacts of climate change. This presentation was assembled as part of the outreach initiative for the Canadian Network for the Detection of Atmospheric Change. 1

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4 Teacher: What else do you know about Nunavut? Responses will vary depending on student knowledge and experience. Addition al Information: Facts about Nunavut can be found at: Nunavut means our land in Inuktituk. Iqaluit is the capital city of Nunavut. Nunavut is the newest Canadian territory; it officially separated from Northwest Territories on April 1 st, The total area of Nunavut is 2,093,190 km 2. The total population is 33,220. 4

5 Teacher: What similarity do you notice in all of the animals shown? Response: All of the animals have white fur. Teacher: Correct. Why do you think many of the animals in the Arctic have white fur? Response: They need fur to maintain a warm body temperature. Their fur is white because it provides excellent camouflage in their snow and ice-covered environment. 5

6 Teacher: Nunavut is the geographically the largest of all thirteen provinces and territories, but is the least populated. 6

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9 Teacher: Raise your hand if you have heard of the ozone layer. What is special about the ozone layer? Response: It protects us from the Sun, chemicals can cause it to break apart, it allows life on Earth to exist, it keeps the Earth at temperatures warm enough for life to exist. 9

10 This slide is a basic review of the Earth s atmosphere. A working knowledge of the atmosphere is required to understand the basics of the greenhouse effect. Note: Diagram is not to scale. Earth s radius is approximately 6371km and Earth s atmosphere is approximately 100km thick.

11 Important Points: - The atmosphere is made up of layers. - It extends to approximately 100km above the Earth s surface. - The ozone layer is located at about 25km in altitude. - Weather occurs in the lowest parts of the atmosphere called the troposphere. Information courtesy of: Teacher: Air becomes less dense as you move away from the Earth s surface. Why might this be the case? Response: The force of gravity is strongest close to the surface of the Earth; this means that most of the atmosphere s air is held close to the surface (in the troposphere). Additional Information: Pressure is displayed in mb (millbars), where 1mb = 100 kpa = 1 atm.

12 Teacher: What are the two major gases found in Earth s atmosphere? Response: The atmosphere is primarily made up of nitrogen and oxygen. The last one percent is made up of everything else (such as trace gases). These exist at levels such as parts per million or parts per thousand. 12

13 The next two slide will point out the important differences between weather and climate. It should be a quick review.

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17 Teacher: Raise your hand if you have heard of the Greenhouse Effect. Would someone like to try to explain or guess what is might mean? Response: The greenhouse effect is a naturally occurring phenomena that is required for life to exist on Earth. Greenhouse gases in the atmosphere trap some of the heat that would otherwise be emitted back into space, thus maintaining a much warmer average global temperature ( 1). 17

18 Teacher: What do you think that Earth s temperature would be is the Greenhouse Effect did not exist? Allow many students to make a guess. Response: -18 C Teacher: What are the names of some GHGs? Response: Water vapour, carbon dioxide, methane, and nitrous oxide Information courtesy of: 18

19 Teacher: Allow students to work in small groups to brainstorm possible sources of GHGs and then lead a classroom discussion. Response: Humans are emitting greenhouse gases to the atmosphere in addition to those that are naturally occurring. Excessive amounts of these gases are increasing the effects of the greenhouse effect. Some sources include plants, animals, soil, oceans, burning fossil fuels, farming and industry. Information courtesy of: 19

20 Teacher: Allow students to provide their own definitions of climate change before showing the one above. Work with a partner to come up with a list of possible effects (can be good or bad) of climate change. Be prepared to allow short discussions/debates about their responses. Responses: Less sea ice Ice on rivers and lakes forming later and breaking up sooner Receding glaciers Accelerated sea level rise Longer, more intense heat waves Stronger storms Plant and animal ranges shift Tress flowering sooner Biodiversity loss through species extinction in many tropical areas and oceans Changed agricultural yields Shift in growing seasons Shifts in rainfall and snow fall patterns 20

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22 Additional Information: The MANTRA (Middle Atmosphere Nitrogen TRend Assessment) balloon is an example of a Canadian balloon mission to study trace gases in the atmosphere. The MANTRA project involved a series of highaltitude balloon flights to investigate changes in the concentrations of midlatitude stratospheric ozone, and of constituents that play a role in ozone chemistry. Four balloons were launched from Vanscoy, Saskatchewan, in August 1998, August 2000, September 2002, and September Each carried a payload of instruments to measure vertical concentration profiles of stratospheric trace gases, and made observations from a float altitude of about 35 km for one day. Several of these instruments were flown years ago and thus provide a link to historical data predating the onset of mid-latitude ozone loss ( SCIAMACHY (SCanning Imaging Absorption spectrometer for AtmosphericCartograpHY ) is a passive remote sensing spectrometer observing backscattered, reflected, transmitted or emitted radiation from the atmosphere and Earth's surface, in the wavelength range between 240 and 2380 nm. The instrument flies on board ENVISAT which was launched on 1 March The primary scientific objective of SCIAMACHY is the global measurement of various trace gases in the troposphere and stratosphere, which are retrieved from the solar irradiance and Earth radiance spectra. The large wavelength is also ideally suited for the determination of aerosols and clouds. Validation of SCIAMACHY is essential to ensure the quality of these derived products ( 22

23 Teacher: Ground-based instruments located all over the world, including PEARL, measure various GHGs. These measurements are compared to the measurements that are being made by the instruments on satellites. In this way, scientists can ensure that the satellite instruments are functioning properly.

24 The following slides are just a couple examples of some of the scientific findings in this field. All of the data shown here is from the IPCC (Intergovernmental Panel on Climate Change) Synthesis Report from 2007 (unless otherwise stated). Information courtesy of: IPCC Fourth Assessment Report: Climate Change 2007: Synthesis Report, mains1.html#1-1

25 Additional Information: The above graphs show the atmospheric concentrations of CO 2, CH 4 and N 2 O over the last 10,000 years (large panels) and since 1750 (inset panels). Measurements are shown from ice cores (the different coloured symbols represent different studies) and atmospheric samples (red lines). The corresponding radiative forcings relative to 1750 are shown on the right hand axes of the large panels. Radiative forcing is a measure of how the energy balance of the Earth-atmosphere system is influenced when factors that affect climate are altered (IPCC Fourth Assessment Report: Climate Change Available from A positive radiative forcing value means that a gas has a warming effect on the climate, while a negative radiate forcing value means that a gas has a cooling effect on the climate. Greenhouse gases have a positive radiative value, or a warming effect. Teacher: Allow students to examine and interpret the plots before discussing as a class. Ask students to provide examples of the sources of each GHG. All three plots show an increase in the concentration of CO 2, CH 4 and N 2 O over the last 10,000 years.

26 Additional Information: The above graph shows observed changes in (a) global average surface temperature; (b) global average sea level from tide gauge (blue) and satellite (red) data and (c) Northern Hemisphere snow cover for March-April. All differences are relative to corresponding averages for the period The smoothed black curves represent decadal averaged values while circles show yearly values. The shaded areas are the uncertainty intervals ( Teacher: Allow students to examine and interpret the plots before discussing as a class. The top plot shows the difference in Earth s surface temperature, relative to the corresponding averages for the period , from 1850 to It can be seen that the average temperature has been increasing and is now 0.5 C above the average temperature from that time period. The middle plot shows the global average sea level difference compared to the average over the same time period. There has been a steady increase in sea level since The bottom plot shows difference in the amount of Northern Hemisphere snow cover. It is clear that the amount of snow cover in the Northern Hemisphere since 1990 has decreased.

27 Teacher: Allow students to examine the figure above before initiating a discussion. 27

28 Teacher: The purpose of this slide is to show a comparison between measured observations of temperature (red) and computer models of temperature (grey). Allow students to discuss the possible origins of temperature change. The figure on the top left shows a model output including only natural effects. The figure on the top right shows model output which includes only anthropogenic (human-caused) effects. The bottom figure shows model results including both impacts. The plots showing only natural or anthropogenic effects show less agreement than the plot showing both natural and anthropogenic effects.

29 Additional Information: IPCC (Intergovernmental Panel on Climate Change) provides a clear scientific view on the current state of climate change knowledge and its socio-economical and environmental impacts. The IPCC website has a wealth of information about climate change. Publications and data are available to the public and can be used to design classroom activities. Visit for more information.

30 Teacher: Allow students to engage in a classroom discussion, split the class into two groups and facilitate a debate, or assign an argumentative essay based on the topic of climate change. In order to have a successful debate, students must be given the necessary time to do appropriate research, or be given the materials (articles, documents, maps, figures, etc.) to interpret before the debate begins. Additional Information: IPCC Likelihood Scale. Virtually certain > 99% probability of occurrence Very likely > 90% probability Likely > 66% probability About as likely as not 33 to 66% probability Unlikely < 33% probability Very unlikely < 10% probability Exceptionally unlikely < 1% probability Courtesy of:

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32 Additional Information: The above plots represent three different scenarios (B1, A1B and A2) proposed by the IPCC. Visit for more information. Teacher: Where do you see the most drastic projected temperature increases? Response: In the Northern hemisphere, or the Arctic region. Teacher: Why might we expect to see more warming in the Arctic region? Response: The melting of snow and ice cover will amplify warming in these regions because there will be a lower albedo (will reflect less sunlight and absorb more). Teacher: Why should the rest of the world be concerned if the Arctic is the region that is most affected? Response: Varied responses should be entertained. The amplified warming in the Arctic, in turn, directly contributes to overall global warming, as well as causing changes in the Arctic that create impacts over the rest of the globe; accelerated sea level rise due to melting of mountain glaciers and ice sheets being the most important example. Additional information: 32

33 Additional Information: Visit for more information about projected changes in precipitation. Note: The teacher should use questions that allow the students to use their critical thinking skills. Teacher: Where do you notice the most dramatic increase in precipitation? Response: The most dramatic increase in precipitation occurs in the Northern Hemisphere between December and February. Teacher: How will this affect that region? Response: More precipitation, coupled with an increase in temperature, may result in less snowfall and more rainfall. This may affect the strength of sea ice, ability of animals to hunt, growing season for vegetation, etc. Teacher: Where do you notice the most dramatic decrease in precipitation? Response: Northern and Southern Africa seems to experience the most dramatic decrease in precipitation. This may result in droughts, decreased crop yields, etc. 33