Ecological Footprint

Caption:What we did and doing is making permanent mark on our planet. (Image Source: http://dieoff.org/Foot.gif)

Ecological Footprints is an environmental accounting tool to estimate the resources consumption, emissions and waster assimilation requirements of a defined human population or economy in terms of corresponding productive land use. A population’s ecological footprint is the total area of productive land or sea required to produce all the crops, meat, seafood, wood and fibre it consumes, to sustain its energy consumption with the biologically productive capacity of the land and sea available to population.

According to the WWF research in 2002, the Earth has about 11.4 billion hectares of productive land and sea space and it is about 1.9 hectares per person. Nevertheless, we consumed 2.3 hectares per person which was 20% above the Earth’s biological capacity. Moreover, due to the wealth gaps between nations, not every one can consume their own productive space. In 1999, the average for North American was about 9.6 hectares per capita, while it was 5.0 hectares per person in Europe and 1.9 for Asian and African. (China is 2.0 hectares per person in 2001)WWF predicted that the humanity’s footprint is likely to grow to about 220% of the earth’s capacity by the year 2050. It means that we need 2 more Earth to sustain our activities at that time!

Yet, there are some limitations to use ecological footprints to estimate the environmental degradation. One major deficiency of this tool is only CO2 emissions are included in land consumption calculation. Other emissions are assumed to be within the carrying capacity of receiving environment but the validity of such assumption is really doubtful.

By the way, I still think that ecological footprints is pretty useful in terms of education as it can help those who do not have science, engineering and environmental background to understand the broad picture of the land required to support their activities on a per capita basis, and of the enormous inequities between nations of the world in access to resources and pressures placed on the planet.

To calculate your own Ecological footprint: Earth Day Footprint
More about Ecological Footprint: Global Footprint Network