Ecological Footprint

The term ecological footprint refers to the overall human impact on the ecosystem and measures the amount of land and ocean area required to sustain the consumption patterns and absorb the wastes on an annual basis of individuals, nations, or industries. The term was coined in academic publications by William Rees of the University of British Columbia and his doctoral candidate Mathis Wackernagel in the early 1990s and later expanded in their 1996 book Our Ecological Footprint: Reducing Human Impact on the Earth. The figurative use of “footprint” was inspired by a computer technician's reference to a new computer's [Page 172]small footprint and calls to mind the prescription, attributed to indigenous peoples, to “walk softly on the Earth.” Other related “footprint” terms have followed.

Typically, the ecological footprint is used in reference to the entire population of Earth, and is measured in “Earths.” For instance, the Global Footprint Network, established in 2003 to actively promote awareness of the ecological footprint concept, measures resources and consumption every year, based on data collected by the United Nations. There is a three-year lag in the collection of data, so that at the end of 2008, the available measurement pertained to consumption as of 2005. According to that data, the ecological footprint in 2005 was 1.3 Earths—meaning that the human population was consuming resources 130 percent faster than the Earth can replenish them. Clearly, that's an unsustainable rate of consumption, which is exactly the purpose of raising awareness: by consuming resources at this rate, we literally risk destroying the very foundation upon which life depends.

The ecological footprint can also be calculated on a per capita basis. Websites offer tools to estimate one's personal ecological footprint—within an understood margin of error—and footprints can be calculated for particular businesses, regions, or industries, which is a useful tool for identifying the relative consumption of different aspects of modern life. The Global Footprint Network makes available a set of ecological footprint standards for calculation at http://www.footprintstandards.com.

Typically, per capita ecological footprint measures are taken of national populations, in order to compare their ecological lifestyles. That 2005 data reveal, for instance, that the footprint per capita in the United States was 9.4 global hectares, compared to 2.1 global hectares in China; 2.1 global hectares per capita is also the Earth's “biocapacity”—the “1 Earth” measurement. In other words, although the global ecological footprint was 1.3 Earths, the U.S. lifestyle applied to the entire population would result in a footprint of 4.48 Earths, 448 percent more than the Earth can replenish. This tells us a number of things, including the fact that there must be a significant population consuming much less than the biocapacity threshold in order to balance out industrialized high-footprint countries like the United States—and indeed, many African countries have such low consumption levels. However, while rates of growth are being curbed in Europe, many of the lowest-footprint areas are increasing their consumption at very fast rates, including the African continent, but particularly countries with rapidly growing production and consumption levels such as China and India.

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