Calculating Rates of Change
Skills and concepts that students must have mastered
How the activity is situated in the course
Content/concepts goals for this activity
Higher order thinking skills goals for this activity
Calculating rates and slopes, comparing results.
Evaluation and interpretation of results.
Other skills goals for this activity
Description and Teaching Materials
After handing out the graphs, I ask students to calculate the rate of change during a period over the past 160 thousand years using the Vostok ice core data (for both temperature and CO2). In order to orient the students, I might ask them about the length of the glacial period vs an interglacial period, or when the most rapid change occurred. The students often work in small groups or check their answers with each other. I ask them to put their answers on the board (there will be a range of answers).
Then I ask them to do the same thing for the modern datasets. Once all the data are on the board, we compare the rates of change. Typically, students have used different units (change per 1000 years vs change per year).
The power of this activity comes from the fact that students have done all the math themselves. So when they are shocked at how different the glacial vs current rates of changes are, I can ask them if they think they made any mathematical mistakes, and since the math is relatively simple (and they can see everyone's answers), they realize that these numbers are correct and these differences in rates are real.
Student Handout in Excel (Excel 237kB May13 13)
Teaching Notes and Tips
I sometimes conduct pre-topic 'quizzes' that include similar questions (open ended). One of the goals of these quizzes is to help students realize that they don't really know the answers to these questions, so that they [hopefully] pay more attention when we do the lecture/activities.
For the question 'What evidence supports the fact that current climate change is driven by human activities?" correct responses increased from 2.5% before the activity to nearly 100% after the activity, even though the answer was not something that I explicitly ever wrote down.