The Ecological Footprint is a sustainability indicator that was introduced in the early ‘90s by Mathis Wackernagel and William Rees, acknowledging the resource limitations of the one planet we have. The Ecological Footprint provides a picture of the environmental consequences of consuming resources.
As a matter of fact, societies use resources (food, energy, etc.) and produce wastes while nature turns waste back into resources. As the GDP tracks monetary flows and provides a picture of the monetary status of a country, the Ecological Footprint tracks resource and waste flows and provides a picture of a country's dependence on natural resources and ecosystem services.
Figure 1: Resource Flow Scheme
Source: Courtesy Global Footprint Network
The Ecological Footprint of an individual is determined by its consumption pattern while the Footprint of a nation is determined by its residents’ number and their average consumption patterns, not by its biocapacity.
Further readings
[1] Wackernagel, M., Rees, W.E. 1996. Our Ecological Footprint: Reducing Human Impact on the Earth. New Society Publishers, Gabriola Island, BC.
[2] Galli, A., Iyengar, L., 2008. The Ecological Footprint: what, why, when to use it. Future Energy Magazine , 2, 57-58.
[3] Kitzes J, Galli A, Bagliani M, Barrett J, Dige G, Ede S, Erb K, Giljum S, Haberl H, Hails C, Jungwirth S, Lenzen M, Lewis K, Loh J, Marchettini N, Messinger H, Milne K, Moles R, Monfreda C, Moran D, Nakano K, Pyhälä A, Rees W, Simmons C, Wackernagel M, Wada Y, Walsh C, Wiedmann T., 2008. A Research Agenda for Improving National Ecological Footprint Accounts. Ecological Economics, doi:10.1016/j.ecolecon.2008.06.022.
[4] Kitzes, J., Wackernagel, M., Loh, J., Peller, A., Goldfinger, S., Cheng, D., Tea, K., 2007. Shrink and Share: Humanity’s Present and Future Ecological Footprint. Philosophical Transactions of the Royal Society, doi:10.1098/rstb.2007.2164.