Ecological footprint

An ecological footprint is a concept based on how much land and water area a human population would need to provide the resources required to sustainably support itself and to absorb its wastes, given prevailing technology. The term was first coined in the early 90's by Canadian ecologist William Rees and Mathias Wackernagel.
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, organisations, industry sectors, regions and nations. 
==Ecological footprint analysis==
Ecological footprint analysis approximates the amount of ecologically productive land and sea area it takes to sustain a population, manufacture a product, or undertake certain acitivities, by accounting the 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. A number of NGO websites allow you to estimate your ecological footprint (see Footprint Calculator, below).
==Changing consumption patterns==
One of the less-publicized but most powerful insights of ecological footprint methods is that, contrary to many people's assumptions, it is human use of renewable resources, not of non-renewable ones, that poses the real sustainability crisis. Nature can restore renewable resources at a certain rate. Humans consistently and increasingly consume renewables faster than ecosystems can restore them.
This state of excessive ecological burden eventually threatens those very ecosystems by not allowing them sufficient time to "recharge." Furthermore, humans can clearly live without nonrenewable resources such as metals or fossil fuels, have done so in the distant past, and will again. It is the renewable resource base on which we and all species depend. The ecological footprint approach can introduce the concept of resource recharge and the rate at which we use resources as key elements in more sustainable human societies. This time element helps us understand that it's not just what we use, or even how much, but how fast, and over what period of time. This meshes with other movements to "slow down" human consumption and help people disengage from that acceleration of actions and expectations that has been a crucial feature of industrial societies.
==Criticisms==
The concept of ecological footprinting has been challenged on several grounds. First, many factors of the calculations are based on crude estimates and it is questioned whether the numbers are applicable to other places (the method is biased to Northern Hemisphere lifestyles). Second, the model generally does not count multiple uses of land: a forest is a carbon sink and the same area is not counted for food production. Third, at the household level, the model is biased in favor of households with more children and against, for instance, single-person ones. The model looks only at the consumption of the household in the present moment, ignoring that each offspring is l consuming household. A large house with ten children can have a "smaller" ecological footprint than a house half its size with only one person.
To counter these uncertainties, the models of ecological footprinting are constantly being refined. Moreover, the use of ecological footprint analysis is considered to be a guide, rather than an exact measure, of sustainability. For instance, few ecological footprint models include the use of fresh or salt water. But since the focus of the ecological footprint is heuristic—to raise awareness, particularly those in more heavily industrialized societies, of their extensive resource use and its externalized costs—greater precision or detail might actually get in the way of this teaching goal.
==References==
*Wackernagel, M. and W. Rees. 1996. Our Ecological Footprint: Reducing Human Impact on the Earth. Gabriola Island, BC: New Society Publishers. ISBN 086571312X
*Chambers, N., Simmons, C. and Wackernagel, M. 2000. Sharing Nature's Interest: ecological footprints as an indicator of sustainability. Earthscan, London ISBN 1853837393 (see also http://www.ecologicalfootprint.com)
==See also==
* Deep ecology
* Ecology movement
* Environmental impact assessment
* The Natural Step
* Urban economics
* Wilderness
==External links==
===General===
*Global Footprint Network Ecological Footprint : Overview
*Best Foot Forward Ecological Footprint experts 
*Sustainability Education Center Our Ecological Footprint
*Ecological Footprint Analysis, Footprint of Nations etc
*The Earth Charter Inititative
*Big Picture TV Free video clip of Matthis Wackernagel, co-creator of ecological footprint analysis
*information on ecological footprinting on the Isle of Wight and general information
===Calculators===
* Redefining Progress - Earth Day footprint quiz
* Eco'tude - for Australian schools
* Ecocal - for UK households