How Do Ice Cores of Glaciers Tell Us about Past Climates?
ES2105  Carbon Dioxide (CO2)Data from the Vostok Ice Core

Scientists can determine the amount of carbon dioxide that was in the air during different time periods by analyzing gas bubbles trapped in ice cores. Carbon dioxide is a greenhouse gas that plays a major role in the atmosphere’s energy balance.

This graph has fewer small peaks and dips than the temperature graph because it was drawn with fewer data points. Study the graph and identify two obvious points when the level of carbon dioxide in the atmosphere increased to a major peak and two points when it dropped significantly to a minimum level before rising again.

  !   Drag the arrows from the tool palette onto the graph to mark these four points. Use another piece of paper to record the ages of all four marked points.

Source: Barnola et al, 1987.
Average CO2 concentration measured from Vostok, Antarctica ice cores.


Compare the timing of the high and low points you labeled on the Temperature and CO2 graphs.

2. Does there appear to be any correlation between the major high and low points on the two graphs? Explain, using specific examples.

3. What do the data suggest about the relationship of temperature and the amount of atmospheric carbon dioxide (CO2)?

4. Which of the two variables, temperature or CO2, appears to have begun rising first?


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