Spring 2004

Talking Science

Measuring Your School's Ecological Footprint

It is important for children to understand that their school’s use of resources has an ecological impact that extends well beyond the school gate. MICHAEL VAN TIEL explains the concept of ecological footprints and introduces the ‘ecotude’ website.

What is an ecological footprint?

Nature provides us with resources in the form of food, forest products, fuel and so on and it also absorbs waste (especially carbon dioxide). An ecological footprint can show the amount of land required to support the lifestyle of an individual, region, industry, community, nation or even a school. It is an estimate of the area a population uses to produce all or part of the natural resources it consumes and to assimilate the waste this generates. Put simply, it calculates the size of our impact on the Earth.

A footprint is measured in ‘units’. Each unit corresponds to one hectare of biologically productive space— about the size of a standard playing field. As people use resources from all over the world, and affect faraway places with their pollution, the footprint is the sum of these areas wherever they are on the planet.

A footprint is calculated by drawing together a range of data on resource use and waste assimilation from a variety of available sources. The size of a footprint can be calculated using different available data and assumptions. Therefore, footprints calculated by different organisations for different reasons may reveal different sized footprints.

Footprints can sometimes underestimate the impact individuals and communities are making because there is so much information about our impact that we currently do not or cannot collect. Impacts, such as gaseous and liquid pollution, cannot always be adequately represented as land areas.

The important thing to remember is that an ecological footprint is an indicator of environmental impact.

How is it used?

Ecologically sustainable footprints tell us about the human pressures on the Earth’s resources and also allow comparisons to be made between the demands placed on nature and the capacity of the Earth to meet these demands. In essence, footprints tell us that humanity is living beyond its means. According to the Living Planet Report 2000, produced by the World Wide Fund International, in 1997 the ecological footprint of the global population was at least 30% larger than the Earth’s biological productive capacity.

Footprints demonstrate the unequal nature of consumption and production of waste among different nations and groups of nations. The ecological footprint of an average consumer in the industrialised world is about four times that of an average consumer in the lower income countries. Australia has a large ecological footprint relative to other nations, indicating high levels of consumption. Our average size footprint is ten hectares. The average for all people on Earth now is about 2.5 hectares.

Footprints can also be used to analyse:

• types of consumption, for example, fossil energy consumption and carbon sinks
• city and regional footprints
• individual footprints
• national footprints compared to the nation’s own productive capacities. For example, the Dutch ‘consume’ a land 15 times larger than their country
• resource intensity of competing technologies or major capital projects (such as a power plant or bridge).

Why is it important?

Many people in urban industrial societies are becoming increasingly distant from the resources that support their lifestyles. Ecological impact of human settlement no longer coincides with geographic locations. Therefore, the impact people are having on the Earth can largely be hidden from them. People only tend to act on a problem when it either affects them personally or is part of their direct experience.

Ecological footprints are one way of clearly bringing the message home that many communities that seem economically prosperous are actually running ecological debts with the rest of the planet.

Footprints can help people see how changes in their behaviour and lifestyle affect the size of their footprint and by how much.

Calculating the ecological footprint of your school

The Powerhouse Museum has launched a new website Eco’tude: changing your ecological attitude (www.powerhousemuseum.com/ ecotude) that allows students to calculate their school’s ecological footprint. The website encourages students to look more closely at how they use their resources in an effort to make the school become more sustainable. The less land a school uses or disturbs, the better it is for everyone.

The Eco’tude web calculator can be used as an influential tool to help students change their school’s ecological attitude by giving them a way to think about how their school is having an impact both within and beyond the school gates. It has been specially designed for Australian schools and uses real Australian data.

The calculator takes pupils step by step through a range of questions. Students can either estimate the answers to these questions, or use the auditing toolkit to investigate the questions and get more accurate figures. The audits in the toolkit not only help students with their estimates but assist them to identify, measure and understand what is happening within their school.

Michael Van Tiel is an education officer at the Powerhouse Museum, specialising in the areas of science and sustainability.

The author owns the copyright in this article. For information related to the reuse of this work in any form please contact the publisher denise.quinn@curriculum.edu.au