What's Your Ecological Footprint?
Lesson 9 of 10
Objective: Students will be able to articulate how the choices they make determine their impact on the environment.
In this lesson, students will use an online interactive website to determine their carbon footprint as a way of measuring their environmental impact. They will then consider their personalized footprint in comparison with the U.S. and global averages and answer reflective questions which will prepare students for a class discussion.
Compared with the other internet data collection and analysis lessons from this unit (Part 1, Part 2, Part 3), this is a shorter interactive lesson appropriate for a class period of 60-75 minutes. However, you may extend the length of this lesson by making the extra credit option (completing a second footprint calculator) a requirement, or extending the discussion.
Access to laptop or desktop computers is essential for this activity as some of the websites have very limited mobile functionality. You may want to plan ahead and schedule a 1 or 2 day block in your school's computer lab if you do not have a class set of computers.
Connection to Standards:
I begin the lesson by reminding students about the predicting environmental impact lesson where we looked at how population growth affects the environment differently depending on the country and factors such as their Carbon emissions per capita.
I then review the concept of per capita Carbon emissions with the following questions:
- Q: "Why are Carbon emissions a good measure of environmental impact?", A: Carbon is a greenhouse gas, the more that is emitted, the more the planet's temperature increases
- Q: "What does per capita mean?", A: it's an average figure positing the behavior of an imaginary "average" citizen based on the data of the population as a whole.
- Q: "Does each member of a country emit the per capita emissions?", A: No, some people are responsible for more emissions, some for less. The per capita figure is an average.
I then let students know that we will be using an interactive website that allows them to enter the details of their own lifestyle to calculate their own ecological footprint (a concept covered in the describing populations lesson earlier in this unit) and determine how their own environmental impact measures up against the U.S. (~27 tons of CO2 per capita) and global (~5.5 tons of CO2 per capita) averages.
At the end of this short warm up, I distribute the activity worksheet and we move on to the independent practice section.
Once we have completed the warm up and the activity worksheet has been distributed, I ask students to either get a laptop from our class set or navigate to the footprint calculator on their smartphones. Since functionality is limited on certain smartphones, it's really preferable that students work on either laptops or on desktops in a computer lab. That being said, several students of mine successfully completed this lesson on smartphones.
Once students have a computer or their smartphones ready, I have them navigate to the Nature Conservancy's carbon footprint calculator. Once there, I use my computer and a projector to show them how to get started and demonstrate that by selecting different options changes the estimated carbon footprint on the right side of the interactive portion of the website.
After that demonstration, I have the students begin their work independently. The calculator itself can be worked through fairly quickly, so even if students are sharing a computer, they can both complete it in less than 15 minutes. Despite the fact that some students will be able to work through the calculator fairly quickly without issue, some students will need assistance with various aspects of the calculator. Therefore, as they are working with the calculator, I walk around to help troubleshoot technical issues and answer any other questions students have (these usually involve defining terms like attached/detached home, efficient lighting, etc.).
If students wish (or if you prefer to extend the lesson), they can also go to the Global Footprint Network's calculator for comparison. This calculator has more interesting graphics than the Nature Conservancy's site, but it does take longer to walk through. If you have more time or computers for every student, it may be good to have them do both calculators so that they may compare their results based on the different questions that each calculator asks. An interesting side discussion or extension question in the reflective discussion might be to ask which calculator they thought was more accurate and to explain why. There's no right answer to such a question, the idea for this lesson is just to have students think more quantitatively about their own consumption habits.
Once students have completed the calculator and answered their questions, we hold a discussion to reflect on the results of their calculations.
One of the groups of questions that make for very interesting conversation are the questions regarding a lifestyle change the students would like to make and how that change would affect their footprint. On the one hand, this is a very easy way for students to talk quantitatively about how their lifestyle impacts the environment. The other, perhaps more substantial point, is that this question allows students to reflect on the "American Dream" of home ownership, a nice car, the ability to take vacations, etc. It's telling that most of my students don't aspire to be fantastically wealthy, just that they might enjoy a middle class lifestyle that most of them don't get to experience.
I try and make sure that a variety of students participate in the discussion. When students' responses vary (i.e., they have different CO2 emissions), I take that opportunity to ask students questions about why they might differ so much. Usually, it has to do with what kind of house they live in, if they have traveled by plane, if they have a car, etc.
The final question from the worksheet regards whether or not the changes they could make to reduce their environmental impact are realistic. (i.e. are they changes that they themselves could make?) What I like about this question is that it allows students to reflect on the fact that altering our collective impact is inextricable from making personal commitments to change. One student impressively utilized vocabulary covered in the previous lesson in his response that the changes he could make to reduce his footprint wouldn't be easy, but they wouldn't be impossible either.
Following the discussion, I collect the worksheets and read over student responses. For any students that did not complete the worksheet in class, I assign it as homework to be collected at the next class meeting. Since this is such a personal lesson, I like to add a little more feedback than usual when grading this assignment to celebrate my student's honesty and willingness to be a bit more self-reflective than I ask them to be on a more typical lesson that might ask them to take more of an outward-facing, "big picture" perspective.