What is an Ecological Footprint?
Ecological footprint is a way of calculating the environmental impact of a society or an activity. The footprint calculates the resources consumed per capita by society or an activity and the disposal of waste by this society or activity in terms of the land area used for such resource consumption and waste disposal (Wackernagel and Rees, 1996).
The calculation of the footprint of a society usually divides consumption into six categories:
We will use transport to and from school as an example of ecological footprint. The purpose of this exercise is to get a class or the whole school to examine ways in which they can reduce the ecological footprint of their journey to school as a communitarian venture.
Most methods of transport require land resources to be consumed, for fuel, vehicle and road construction and for forests to absorb the waste gases (Figure 5.4.3). (Carbon monoxide will subsequently be converted into carbon dioxide). This resource use can be converted into land area, in this case square metres. On this basis we can work out the ecological footprint of travelling 10km (6.25 miles) to and from school each year by different methods of transport in square metres (Figure 5.4.4).
A bus uses more fuel and road space and emits more carbon monoxide per kilometre than a car but its ecological footprint per capita is less because it carries more passengers. The ecological footprint of cycling or walking mainly takes into account the extra food that has to be consumed to provide the energy to travel 10km.
It is possible to calculate the ecological footprint for society based on all its resource use and waste disposal. Table 5.4.1 shows the breakdown of the ecological footprint of the average Canadian. Table 5.4.2 shows different ecological footprints for different countries. Both these tables are derived from data in Wackernagel and Rees (1996).
Younger children may find it difficult to understand a diagram like Figure 5.4.3. The concept of ecological footprint may be conveyed to younger children more easily if they are asked where they get the energy to walk or to run? What are the waste products from the human body? Where do these waste products go? It should be easier for young children to associate the growing of food and the processing and dumping of waste with a specific land area.