|
Printer-friendly PDF version (249 KB)
Adapted from Facing the Future, www.facingthefuture.org
Overview
Students graph data to examine seasonal and long-term atmospheric carbon dioxide trends over the past 45 years and then predict future carbon dioxide emissions.
Objectives
Students will:
- Identify processes that contribute to CO2 emissions
- Graph CO2 emissions
- Assess the relationship between atmospheric carbon dioxide and global surface temperatures
- Brainstorm ways to reduce CO2 emissions
Subject
Science, Math
Suggested Grade Level
9-12
Materials
- Graph paper or a graphing program such as Microsoft Excel
- Handout: CO2 Dataset, 1 per student pair
- Overhead: long-term carbon dioxide and temperature trends
______________________________________________________________________________________________________
INTRODUCTION
- Ask students to recall which gases are involved in the greenhouse effect (water vapor, carbon dioxide, methane, and nitrous oxide, along with manmade gases). Tell students that today they'll be exploring historical trends in carbon dioxide emissions. Explain that CO2 is an important greenhouse gas that has been linked to many human activities.
- Ask students if they can name some activities (human or otherwise) that might add CO2 to our atmosphere - burning fossil fuels, cutting tress, burning wood, volcanoes, all release CO2).
PROCEDURE
- Divide the class into pairs
- Give each pair 1 sheet of graph paper and 1 CO2 data set (source: http://cdiac.ornl.gov/trends/CO2/sio-mlo.htm)
- Have students graph the data (year should be on the x-axis and CO2 emissions on the y-axis. The scale should be appropriate for the data.) Students can use a computer graphing program as an alternative to graphing by hand.
- Ask students to predict an average CO2 concentration for the year 2020 and put a star on their graph to represent that number on the graph.
- Reconvene the class to view and discuss the graphs from the Woods Hole Research Center on historical temperature and CO2 trends. Ask students to explain what they see in these graphs. Where is the yearly CO2 data shown in these graphs? When does the most recent warming trend begin?
- Bring the class together for a discussion using the following reflection questions.
REFLECTION
- What might account for differences in the CO2 concentrations measured in May and October of each year?
- A: Lower values represent increased CO2 uptake during the summer when plants are photosynthesizing more; high values represent decreased photosynthesis during the winter.)
- How could we take advantage of those natural periods of increased CO2 uptake to reduce overall CO2 in our atmosphere?
- Based on the data shown on your graph, what do you think the CO2 concentration will be in the year 2020?
- Why do you think carbon dioxide levels have continued to rise during the past 45 years?
- What types of activities might raise carbon dioxide levels even faster?
- How do you think this will affect Earth's climate? Predict how your life will be different if this climate change occurs.
- What types of actions can we take to lower our CO2 emissions?
|
