Ecological Footprints 3 - Guide to Assignment

A Worked Example As A Guide To The Estimate of the Ecological Footprint

Dr David Galbraith

The objective of the Ecological Footprint Assignment that was presented in Science 2K03: Evolution, Heredity and teh Environment, was to have each student estimate their individual ecological footprint, and then to extrapolate from that result to estimate the ecological footprint of cities or towns.

This note is intended as a guide to completing the assignment as printed in the Custom Courseware, and includes a worked example. Follow the example from Box 1 through 8 to see how the process is intended to work.

Basic idea: Add Up Those "Points"

The calculation of ecological footprints that was introduced by Wackernagel and Rees is based on an extensive review of the effects of various activities and the costs to support them in terms of land used. Our assignment is quite a bit simpler than the original calculation, because a series of simplified point values was worked out by Dr Wolff-Michael Roth of the University of Victoria.

Each of the major areas of our lifestyle and consumption is represented by a box: transportation, water use, clothing, recreation, food, garbage and living space. Within each box, you are expected to add up points representing various activities. The totals for each of the seven boxes are then added up on the final page, in Box 8.

Here's a worked example:

Box 1. Transportation NOTE: On a typical day, how many times to you use a car or take a bus or bike ride? List the number of daily trips in the third column, and then multiply each by the appropriate number of points to get the subtotal. Add up all of the points on this page for the transportation total points. That number (150 in this example) gets carried forward to Box 8. Yuch - this is just like doing a tax return!!
Type of Trip	Points	x Daily Trips =	Subtotal
Walking	0	3	0
Cycling	15	2	30
Public Transit	30	1	30
Car Pool	45	0	0
Private Vehicle	90	1	90
Total Points for Transportation:			150

Box 2. Water Use NOTE: As above, work across each line - if you didn't do a particular activity, leave that line blank or enter a "zero".
Type of Activity	Points x	Daily Uses =	Subtotal
Did not shower or bathe	0	0	0
1 - 2min. shower	15	0	0
3 - 6min. shower	30	1	30
10 min shower	60	0	0
I bathed in a full tub	60	0	0
I bathed in a half-full tub	30	0	0
I took a long shower with a friend	30	0	0
I left the water running when I brushed my teeth	15	1	15
Total Points for Water Use:			45

Box 3. Clothing NOTE: Getting the hang of it? This is the only box with a "negative" point score - you get some points returned if you wear mended clothing!
Item	Options	Points	Subtotal
I am wearing the same clothes today that I wore yesterday	Most	0	0
	Some	15	0
	None	30	30
I am wearing something that has been mended		- 15	-15
I did the mending		-15	0
Total Points for Clothing Choices:			15

Box 4. Recreation and Discretionary Spending NOTE: Recreational land use is difficult to add up for individuals, because unless you are very rich you likely share pools or tracks with many hundreds of other people. Identify the games, sports and activities you participate in during your spare time.
Type of Activity	Options	Points	Subtotal
How much equipment did you need to participate in your favorite sports?	Quite a bit	60	0
	Some	30	30
	None	0	0
How much land was converted to playing fields, ice rinks, swimming pools, gym space, ski runs, etc. to meet your recreation needs? NOTE: Divide the total hectares by the number of people you shared this space with for "Much"	None or little	0	0
	Some (<1 hectare)	0	0
	Much (>1 hectare)	10/1	1
I spend the following amount daily on purchases (food, clothing, magazines, sports equipment, etc.):	$12 * 3= Three points per dollar:		36
Total Points for Recreational Choices:			67

Box 5. Food
Type of Activity	Options	Points	Subtotal
On an average day, how many portions of meat do you eat?	None	0	0
	1	30	30
	2	60	0
	3	90	0
How much food do you leave on your plate ?	None	0	0
	Very little	15	0
	More than a little	30	0
I composted all vegetable and fruit scraps	Yes	0	0
	No	30	0
The food I eat is locally grown	All of it	0	0
	Some of it	30	30
	None of it	60	0
The food I ate was packaged in paper or plastic	None of it	0	0
	Some of it	30	30
	All of it	60	0
Total Points for Eating Habits:			90

Box 6. Household Garbage/Refuse sent to Land Fills
Type of Activity	Options	Points	Subtotal
The garbage I produce in an average day would fill a container of this size:	A fruit crate	90	0
	A shoe box	60	60
	A cup	30	0
	I produce no garbage	0	0
Total Points for Daily Garbage Habits:			60

Box 7. Living and Office Space

Type of Activity

Indoor Space

Area (m²)

People

Subtotal (Area/People)

Calculate in square meters the indoor space that you require. Include all the space in your "home", "office", etc. (1 sq. meter ~ 10 sq. feet). Divide the total square meters by the number of people you shared this space with.

Home Space

120

3

40

Office Space

200

4

50

Other Space

0

0

0

Total Points for Indoor Space:

90

Box 8: Final Calculations

NOTE: To complete the process, take each box's subtotal and enter it on this page. The "Running total" column has been added to make the addition a little easier. for this, you need to look up the population and area of your particular city. A list of area cities (<link) and towns has been prepared from information on the Statistics Canada web site. Let us know which city you are using for your calculations!

Topical Box:

Subtotal

Running Total

Box 1: Transportation

150

150

Box 2. Water Use

45

195

Box 3. Clothing

15

210

Box 4. Recreation and Discretionary Spending

97

307

Box 5. Food

90

397

Box 6. Household Garbage/Refuse sent to Land Fills

60

457

Box 7. Living and Office Space

90

547

Add up all box totals for "Total Points":

547 Points

Divide Total Points by 100 to estimate Personal Ecological Footprint in Hectares:

5.47 hectares (hectares are abbreviated "ha")

Number of Persons in your Municipality (look up Greater Hamilton Area):

624,360 people

Multiply Personal Footprint by Number of Persons to estimate the Ecological Footprint of your Municipality:

5.47 ha x 624,360 people

= 3,415,249.2 ha

Divide by 100 to convert hectares to square kilometers

34,152.5 km²

What is the actual size of your municipality? (look up Greater Hamilton Area):

1,359 km²

What is the ratio of footprint to actual size?

34,52.5/1,359 = 25.1

So the ratio is: 25.1:1

Note: In other words, the ecological footprint of the combined population in the Hamilton region is 25 times larger than the actual land within the boundaries of the region (GHA) in this example. It takes about 25x as much land as is in the GHA to support the lifestyle of all of the people in the GHA if they have the same lifestyle as you!