According to Wikipedia: Ecological footprint analysis approximates the amount of arable and agriculturally or ecologically productive land area it takes to sustain one human or group of humans, say in a family or city, based on their use of energy, food, water, building material and other consumables. It is a way of determining relative consumption for the purpose of educating people about their resource use and, sometimes, triggering them to change how they consume. It can be combined with overpopulation concerns and stated as “the number of Earths it would take to support every human living exactly the way you do.” Ecological footprints have been used to argue that current lifestyles are not sustainable.
weblink: Wikipedia Footprint from: Wikipedia in detail see also: Footprint (ecological) XlnkS6DF XlnkC193A