Ecological Footprint

Coined by William Rees — the Canadian ecologist and professor at the University of British Columbia — in 1995 in his book Our Ecological Footprint: Reducing Human Impact on the Earth, the term 'ecological footprint', or EF, is a refreshing new model to measure human impact on the environment. It aims to bring to fore the extent of environmental degradation caused in the name of human development, ever since the 18^th century.

EF analysis attempts to measure the demand humankind makes on nature, and it measures the ratio of human consumption of natural resources with the capacity of the earth to regenerate them. It also estimates the land area a human population would require if the current consumption of resources and the pollution caused by this activity is matched by renewable resource production and waste assimilation in this particular land area.

How it Works

EF analysis approximates the human impact upon the environment by calculating the draw upon ecologically productive land and/or marine area required to sustain a population, manufacture a product or undertake various activities. This is achieved through a system of accounting similar to life cycle analysis wherein the consumption of energy, biomass (food, fiber), building material, water and other resources are converted into a normalized measure of land area, dubbed 'global hectares' (gha).

Per capita EF is a means of determining relative consumption and can be a useful tool to educate people about our planet’s Carrying Capacity and the impact of over-consumption, with the aim of altering personal behavior. Ecological footprints may be used to argue that many contemporary lifestyles are not sustainable. The average "earthshare" available to each human citizen is approximately 1.9 gha per capita. The US footprint per capita is 9.5, and that of Switzerland is 4 gha, whilst China's is approximately 1.5 gha. The WWF claims that the human footprint has exceeded the biocapacity, i.e. the available supply of natural resources, of the planet by 25%.

How Effective is It?

EF analysis has met with some criticism. In most developed nations, fossil fuels use cause more than 50 per cent of the EF, results in an EF approximately twice the earthshare. This is based on estimating the land area and plants, such as new forests, needed to sequester the CO2 released from burning fossil fuels, assuming it to be the most effective method. Critics argue that this is an very unlikely and uneconomic way to stop global warming. There are many other methods for mitigation of global warming which do not require such large land use.

The EF was designed to only account for consumption of renewable resources, or perfect substitutes thereof as if the renewable resource had been used. Therefore, methods such as using biomass to meet energy demands cannot be used, as the amount of land required to produce sufficient biomass cannot be calculated and factored into the gha value (as it brings human energy systems into the equation). Furthermore, the EF does not take into account transportation requirements and critics argue that without the benefits of trade, this system can only be applied globally.

The problem is solved if the EF value is complemented with other indicators, such as one for biodiversity, ecological economics or ecosystem valuation.

Ecological footprinting is now widely used around the globe as an indicator of environmental sustainability. It can be used to measure and manage the use of resources throughout the economy. It is commonly used to explore the sustainability of individual lifestyles, goods and services, organizations, industry sectors, neighborhoods, cities, regions and nations.

References and Useful Websites

• Sustainable Development and the Environment by A. M. Thirumurthy, F. Fanthome
• Encyclopaedia Britannica 2005
• MyFootPrint
• Environment and Urbanisation, Vol. 4, by W. Rees
• Ecological Economics by J.C.J.M. van den Bergh and H. Verbruggen