Our Ecological Footprints

Grade 7 Physical Science - Interactions with Ecosystems

Outcome IE7.2 Observe, illustrate and analyze living organisms within local ecosystems as part of interconnected food webs, populations and communities.

This activity involves the students becoming aware of their personal ecological footprint through transportation, food, waste, energy, and water.  The students devise a plan which they can carry out to reduce the size of their ecological footprint.

Objectives

• Students will understand what is meant by the term ecological footprint.
• Students will reflect on their personal impact on the environment.
• Students will come up with ways they can reduce the size of their ecological footprint.

Motivational Set

1) Invite students to trace around their own foot (shoe on or off), on graph paper.

2) Have students calculate the area of their footprint.

3) Discuss that we all leave marks on our environment. Our shoe prints are only one of the outward signs of our being on the earth. We affect our environment in many other ways. Explain to the students that an ecological footprint is a way to measure our impact on the environment. The larger the footprint, the more negative effect on the Earth.

4) Invite the students to paste pictures of ways they affect our environment on their paper footprints.

5) As a class, share their ecological footprints.

Lesson 1

What is an Ecological Footprint?

1) Explain to students that there are approximately 6.5 billion people on the planet Earth. The Earth has about 1.8 hectares of productive land available per person for human use. This excludes deserts, oceans, ice caps, mountains and areas already covered by pavement. Canadians on average use 7.5 hectares apiece. The World average is only 2.2 hectares. If the entire population of the Earth used as much as Canadians do we would need 4 Earths to support us.

2) To get a clearer picture of our impact on the planet, you could measure out 7.5 hectares and compare it to 2.2 hectares. A hectare is 100 meters by 100 meters.

3) In the next lesson we will look into 5 of the areas that are used to calculate our personal ecological footprints. These are water, transportation, energy, food and garbage.

4) Give students "Student Footprint Surveys" to fill in for the next class. The information the students collect should be based over an entire day. Assure the students that this information will be kept confidential.

Lesson 2

How Big is My Ecological Footprint?

1) Today the students will compile the information collected from the "Student Footprint Surveys". Collect the surveys to help keep information confidential. Each student should be given a sheet to help record the information.

Worksheets attached in PDF format:

Water;  Transportation; Garbage; Food; Energy

2) Analyzing 5 areas of our ecological footprint
Water

1. Read out the number of flushes, so that the students can record them. You may choose to also record on an overhead, smartboard or chart paper, for the students to follow along with.
2. Finish the rest of the worksheet with the students, or have them work on them individually for a few minutes.

Transportation, Energy, Food and Garbage
Follow the procedures used for "water".

3) Reflection on data found for the 5 areas - may want to do as a class discussion or as small group discussions. This may take more than 1 class.

a. Water
What is the mean number of flushes for this class?
The average toilet uses 13 litres per flush, although some older toilets use up to 20 litres. How much water was used by the class based on this mean?
How much water could be saved, if each toilet flush was reduced by 1 litre?
What can you do to reduce the amount of water your toilet uses? (install dams (pop bottle filled with water/rocks), replace, etc.)
Why should Canadians use less water, when there is so much fresh water available to us?
b. Transportation
What are the pros and cons of each mode of transportation used by this class. See chart as an example.

c.  Energy

Which device did the class use the most?
100 years ago, how do you think people your age entertained themselves? Do you think their ecological footprint was larger or smaller than yours, why?
How does your choice of entertainment affect your ecological footprint?

d. Food

• Which food groups do you think contribute to a larger ecological footprint? Why? Examples: Meats, because they require the plants to eat, which have already used land, water and sunlight, and take up land. Processed and frozen foods because they require additional processes/energy to keep them on the shelf longer.
• What kinds of foods are in the "other" category?
• What relationship do you see between the "other" foods and foods that contribute to larger ecological footprints?
• What are some ways you could reduce your "food footprint"? Follow the "5 n's" (Candace Savage, Eat Up! Healthy Food for a Healthy Earth, (Vancouver:Douglas & McTntyre, 1992))
• Nutritious - Choose foods that nourish and help you stay healthy. Generally, nutritious foods have fewer additives and are less processed. ex. Yogurt versus ice cream
• Natural - Choose foods that most closely resemble what the food looked like when it was first harvested. ex baked potato versus crinkle-cut French fries - less processing and fewer additives
• Near - Choose foods that are grown in your area. ‘Near' is a relative term; choose foods produced in your own country rather than from across the world. ex. An apple versus a mango Less travel time for the food to get to you, therefore less fuel burned, fresher product, generally cheaper, and you're supporting local economy.
• Now (closely related to "near") - Choose foods that are in season, or in winter canned or frozen - Less travel time as the item does not need to be imported from afar and is less likely to have additives added to be kept fresh.
• Naked - Choose foods with little or no packaging ex. Chicken nuggets (even though highly processed) packaged in a plastic bag over nuggets packaged in bag and cardboard, or fruit by the piece instead of in protective hard plastic casing.

e. Garbage
Of the items thrown away by your class, which type had the most pieces? What percentage of the total items thrown away was this?
If you took all the garbage your class threw into the garbage, which category would take up the most space? Why do you think so?
Look at the garbage data for your class. How can you reduce your "garbage footprint"?
Of the total items, what percentage was thrown away? What percentage was recycled? How much was diverted?
How would items diverted from being thrown away lower the Ecological Footprint?

4) At this point you may want the students to actually calculate their ecological footprint. Listed are several web sites where they can do this.

• Ecovageurs - calculate your eco-footprint
• Royal Saskatchewan Museum footprint calculator - compares your footprint to other countries
• Zerofootprint Kids Calculator - breaks results into areas - an easier footprint calculator
• Ecological Footprint; How does the way we live affect the earth? - a pdf version for handouts
• Global Footprint Network footprint calculator - a bit involved - perhaps better for teachers

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Lesson 3

What Can I Do?

Students will be devising their own "ecoplans" to help reduce ecological footprints. This should be given a few class periods to complete. You may choose to have the students carry out their plans (ideal) or you may only want them to devise the plans. If the students are to carry out their plans, make sure you give them a time frame, so they can choose a project that fits their time allotted.

1) Group the students into small groups, should have at least 5 groups - 1 for each of the aspects of our ecological footprints. (water, transportation, food, garbage, energy)

2) Assign or allow each group to decide which area they are going to develop an ecoplan for - water, transportation, food, energy, garbage.

3) Hand out worksheets to help lead the students through the development and implementation of their ecoplans.

1. Choosing an "ecoplan"
2. How to Do it (includes a checklist)
3. Group Evaluation
4. Self Evaluation and Reflection

4) Give students time to present their findings. Some interesting ways to present findings could include an oral presentation, or stand-up posters, or science fair style, where students could field questions about their plans.

 Other fun:

Ecological Footprint Crossword

Ecological Footprint Word Find

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