Ecological Footprints Laboratory Exercise
Like all species, humans need certain resources to survive. However, humans consume resources not
only for survival, but also for comfort, luxury and prestige. Whereas non-human species generally must
obtain their resources from within their ecosystem, in contrast, humans have derived ways
(transportation) to remove resources from other ecosystems to satisfy their wants and desires. However,
societies are not equal in their ability to extract, transport, process, manufacture, and use resources.
And, societies have different philosophies and cultural perspectives regarding their desire to utilize
resources beyond basic needs. Thus, there is a question of equitable distribution of resources among
human societies and between humans and other species.
In addition to resource extraction, an additional crucial ecosystem function is the assimilation of wastes
(e.g. air, water and soil pollution; hazardous, solid and radioactive waste; and waste heat). Again
humans have devised ways to discharge wastes into other ecosystems by building tall smoke stacks,
dumping waste in flowing rivers and oceans, and shipping wastes around the world.
The area of productive land required to provide resources and assimilate waste to meet consumption
needs is referred to as the ecological footprint (Wackernagel and Rees, 1996(). This is different from
the carrying capacity, which is the maximum abundance of a population that can be sustained by a
habitat or ecosystem without degrading the habitat or ecosystem. Because non-humans cannot extract
resources from outside their ecosystem, their population cannot exceed the carrying capacity, which is
based on the availability and amount of an ecosystem’s resources. Thus, a non-human’s ecological
footprint is limited by the size of the ecosystem. In contrast humans have a carrying capacity for their
“ecosystem” (for example, a country). However, because humans can transfer resources from another
country, their ecological footprint can exceed the carrying capacity. Thus, the United States’ ecological
footprint can exceed the carrying capacity of the United States (i.e. the U. S. can maintain more people
than available resources) because resources are extracted from Mexico, Africa, Saudi Arabia, and so
forth. Clearly this means that for some countries, their ecological footprint must be smaller than the
carrying capacity because the Earth has a finite amount of resources. Or, some populations must live
near the subsistence level, whereas others can live in high comfort.
The ecological footprint is one measure of the sustainability of a society’s current lifestyle. However,
this is an anthropocentric view. If humans consume all the resources or take over all the biologically
productive land, what about non-humans? And what about humans in less developed countries? This is
an issue of environmental equity. In developing nations such as India, about one hectare is needed to
meet the resources requirements of an average person. In the United States, the average individual
ecological foot print is 10 hectares (24 acres). If everyone in the world consumed resources equal to the
average American, we could need 5 Earths.
Name: ______________________________________
DUE BEFORE CLASS 9/24
1. Go to the following website to calculate your ecological footprint: www.myfootprint.org.
2. Click on “footprint for you” and follow the quiz to calculate your ecological footprint
Number of planets needed:
Category
Acres of My
Footprint
Acres of National
Average Footprint
Acres of My
Footprint
Acres of National
Average Footprint
Carbon
Food
Housing
Goods and Services
Total
Biome Footprint
Cropland Footprint
Pastureland Footprint
Marine Fisheries Footprint
Forestland Footprint
3. How does your footprint compare to the average American footprint? Why do you think you are
higher or lower than the average American?
4. How can reduce your ecological footprint most effectively? (Hint: Change some of the answers
that you can change in your lifestyle and see how this changes your footprint). What constraints
may keep you from reducing your consumption any further?
5. How do you feel about your consumption pattern and how it affects other humans on Earth? Do
you think that you have an moral obligation to reduce your footprint?
6. Does this exercise make you want to change your lifestyle slightly? What might you work on
changing right away?