Objectives:  After completing the following exercise students will be able to perform the following tasks:

1. form and complete a graph
2. extrapolate future data points based on observed trends or patterns
3. observe relationships between two sets of data

Subjects:  Science, Math

Background Information:  Global warming is one of the most important and controversial environmental concerns of modern times.  Some models suggest that the average temperature of the earth will increase by 3 to 5 degrees Celsius within the next 50 years.  Others predict that the earth's natural sinks, oceans and forests, will adapt to absorb more carbon dioxide to provide an equilibrium point in the near future.  If global warming continues at its current rate the climate of the entire earth will be dramatically changed.

Government climate data has been accurately kept for approximately one hundred years.   This information is available on the Internet at http://www.ncdc.noaa.gov.   For schools without Internet access there is a sample data sheet included for both carbon dioxide and average global temperatures.  This exercise will enable students to use real data to perform specific calculations and extrapolate the effect and magnitude of human activity on earth's climate.

Level:  This activity is appropriate for students at the eighth or ninth grade levels.

Time:  45 minutes

Materials:

• Climate data from http://www.worldclimate.com/climate/index.htm or sample data sheet.
• Two sheets of graph paper.

Pre activity questions:

1. What effect does increased carbon dioxide concentration have on the average global temperature?

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2. What human activity is the main source of carbon dioxide in the environment?

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3. What ways do you think that greenhouse emissions can be reduced?

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4. What are the two most important natural storage areas for carbon dioxide?

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5. The national government has been recording climatological data for the last ________years.
 

Procedure:

1. Answer the pre-activity questions.
2. Construct a graph on which to display the data.  Make sure you title and label your graph properly.
3. Record temperature and carbon dioxide data from the link or sample data sheet. (The sample data sheet can be
    used to plot the relationship between temperature and another variable for a particular city that will be
    assigned by the teacher.)
4. Plot the relationship of average temperature versus time.
5. Plot carbon dioxide concentration verses time on the second sheet of graph paper.
6. For sample data sheet:  plot the temperature at a given city verses another value that has been
    recorded in the data table from a web site.
7. Answer the post lab questions.
 

Data:

Sample data table:
 (sample data from NOAA Reports to the Nation, No. 4, Fall 1997)
 

Data table 1: Data available from http://www.worldclimate.com/climate/index.htm.
                     CO2 data can be obtained from http://www.cdiac.esd.ornl.gov/home.htmlhttp://www.worldclimate.com/climate/index.htm

Post lab questions: For use with sample data table.

1. From your graph, what will the average temperature of the earth be in 2020 if the current trend in global warming continues?

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2. What relationship is shown to exist between the average global temperature and carbon dioxide concentration?

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3. If carbon dioxide levels return to pre-1900 levels what will happen to the average global temperature?

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4. In what year was the greatest increase in carbon dioxide levels recorded?  ______  What are possible reasons for the increase?

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5. What effect will increased industrialization of developing countries such as China and India have on the climate?

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Conclusion: Although the effect of carbon dioxide on average global temperature is a relatively recent discovery, it has caused concern the world over.  The correlation between the two values is significant enough to cause great concern among all people on earth.  Large portions of land would be flooded if/when the ice sheets melt.  The heating of the water in the oceans would cause them to expand, which would add to the flooding.  The problem has reached such proportions that the countries of the world have developed ways of sharing the cost of dealing with it. This web site has the information on the Kyoto treaty : http://www.cnn.com/SPECIALS/1997/global.warming/stories/treaty .

Woodrow Wilson Leadership Program in Environmental Science lpt@www.woodrow.org
The Woodrow Wilson National Fellowship Foundation webmaster@woodrow.org
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