The ecological footprint is a measure of human demand on the Earth's ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet's ecological capacity to regenerate. It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to mitigate associated waste. Using this assessment, it is possible to estimate how much of the Earth (or how many planet Earths) it would take to support humanity if everybody followed a given lifestyle. For 2006, humanity's total ecological footprint was estimated at 1.4 planet Earths – in other words, humanity uses ecological services 1.4 times as fast as Earth can renew them. Every year, this number is recalculated — with a three year lag due to the time it takes for the UN to collect and publish all the underlying statistics.
The first academic publication about the ecological footprint was by William Rees in 1992. The ecological footprint concept and calculation method was developed as the PhD dissertation of Mathis Wackernagel, under Rees' supervision at theUniversity of British Columbia in Vancouver, Canada, from 1990–1994. Originally, Wackernagel and Rees called the concept "appropriated carrying capacity". To make the idea more accessible, Rees came up with the term "ecological footprint," inspired by a computer technician who praised his new computer's "small footprint on the desk." In early 1996, Wackernagel and Rees published the book Our Ecological Footprint: Reducing Human Impact on the Earth.
Ecological footprint analysis compares human demand on nature with the biosphere's ability to regenerate resources and provide services. It does this by assessing the biologically productive land and marine area required to produce the resources a population consumes and absorb the corresponding waste, using prevailing technology. Footprint values at the end of a survey are categorized for Carbon, Food, Housing, and Goods and Services as well as the total footprint number of Earths needed to sustain the world's population at that level of consumption. This approach can also be applied to an activity such as the manufacturing of a product or driving of a car. This resource accounting is similar to life cycle analysis wherein the consumption of energy, biomass (food, fiber), building material, water and other resources are converted into a normalized measure of land area called 'global hectares' (gha).
Per capita ecological footprint (EF) is a means of comparing consumption and lifestyles, and checking this against nature's ability to provide for this consumption. The tool can inform policy by examining to what extent a nation uses more (or less) than is available within its territory, or to what extent the nation's lifestyle would be replicable worldwide. The footprint can also be a useful tool to educate people about carrying capacity and over-consumption, with the aim of altering personal behavior. Ecological footprints may be used to argue that many current lifestyles are not sustainable. Such a global comparison also clearly shows the inequalities of resource use on this planet at the beginning of the twenty-first century.
In 2006, the average biologically productive area per person worldwide was approximately 1.8 global hectares (gha) per capita. The U.S. footprint per capita was 9.0 gha, and that of Switzerland was 5.6 gha per person, while China's was 1.8 gha per person. The WWF claims that the human footprint has exceeded the biocapacity (the available supply of natural resources) of the planet by 20%. Wackernagel and Rees originally estimated that the available biological capacity for the 6 billion people on Earth at that time was about 1.3 hectares per person, which is smaller than the 1.8 global hectares published for 2006, because the initial studies neither used global hectares nor included bioproductive marine areas.
Ecological footprint analysis 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 can be used to explore the sustainability of individual lifestyles, goods and services, organizations, industry sectors, neighborhoods, cities, regions and nations. Since 2006, a first set of ecological footprint standards exist that detail both communication and calculation procedures. They are available at www.footprintstandards.org and were developed in a public process facilitated by Global Footprint Network and its partner organizations.
The ecological footprint accounting method at the national level is described in the Ecological Footprint Atlas 2010  or in more detail in the Calculation Methodology for the National Footprint Accounts . The National Accounts Review Committee has also published a research agenda on how the method will be improved.
There have been differences in the methodology used by various ecological footprint studies. Examples include how sea area should be counted, how to account for fossil fuels, how to account for nuclear power (many studies simply consider it to have the same ecological footprint as fossil fuels), which data sources used, when average global numbers or local numbers should be used when looking at a specific area, how space for biodiversity should be included, and how imports/exports should be accounted for.. However, with the new footprint standards, the methods are converging.
In 2003, Jason Venetoulis, PhD, Carl Mas, Christopher Gudoet, Dahlia Chazan, and John Talberth -a team of researchers at Redefining- developed Footprint 2.0. Footprint 2.0 offers a series of theoretical and methodological improvements to the standard footprint approach. The primary advancements were to include the entire surface of the Earth in biocapacity estimates, allocate space for other (non-human) species, change the basis of equivalence factors from agricultural land to net primary productivity (NPP), and change the carbon component of the footprint, based on global carbon models. The advancements were peer reviewed and published in several books, and have been well received by teachers, researchers, and advocacy organizations concerned about the ecological implications of humanity's footprint.
Studies in the United Kingdom
The UK's average ecological footprint is 5.45 global hectares per capita (gha) with variations between regions ranging from 4.80 gha (Wales) to 5.56 gha (East England). Two recent studies have examined relatively low-impact small communities. BedZED, a 96-home mixed-income housing development in South London, was designed by Bill Dunster Architects and sustainability consultants BioRegional for the Peabody Trust. Despite being populated by relatively "mainstream" home-buyers, BedZED was found to have a footprint of 3.20 gha due to on-site renewable energy production, energy-efficient architecture, and an extensive green lifestyles program that included on-site London's first carsharing club. The report did not measure the added footprint of the 15,000 visitors who have toured BedZED since its completion in 2002. Findhorn Ecovillage, a rural intentional community in Moray, Scotland, had a total footprint of 2.56 gha, including both the many guests and visitors who travel to the community to undertake residential courses there and the nearby campus of Cluny Hill College. However, the residents alone have a footprint of 2.71 gha, a little over half the UK national average and one of the lowest ecological footprints of any community measured so far in the industrialized world Keveral Farm, an organic farming community in Cornwall, was found to have a footprint of 2.4 gha, though with substantial differences in footprints among community members.
Early criticism was published by van den Bergh and Verbruggen in 1999; another criticism was published in 2008. A more complete review commissioned by the Directorate-General for the Environment (European Commission) and published in June 2008 provides the most updated independent assessment of the method. A number of countries have engaged in research collaborations to test the validity of the method. This includes Switzerland, Germany, United Arab Emirates, and Belgium.
Grazi et al. (2007) have performed a systematic comparison of the ecological footprint method with spatial welfare analysis that includes environmental externalities, agglomeration effects and trade advantages. They find that the two methods can lead to very distinct, and even opposite, rankings of different spatial patterns of economic activity. However, this should not be surprising, since the two methods address different research questions.
Calculating the ecological footprint for densely populated areas, such as a city or small country with a comparatively large population — e.g. New York and Singapore respectively — may lead to the perception of these populations as "parasitic". This is because these communities have little intrinsic biocapacity, and instead must rely upon large hinterlands. Critics argue that this is a dubious characterization since mechanized rural farmers in developed nations may easily consume more resources than urban inhabitants, due to transportation requirements and the unavailability ofeconomies of scale. Furthermore, such moral conclusions seem to be an argument for autarky. Some even take this train of thought a step further, claiming that the Footprint denies the benefits of trade. Therefore, the critics argue that the Footprint can only be applied globally.
The method seems to reward the replacement of original ecosystems with high-productivity agricultural monocultures by assigning a higher biocapacity to such regions. For example, replacing ancient woodlands or tropical forests with monoculture forests or plantations may improve the ecological footprint. Similarly, if organic farming yields were lower than those of conventional methods, this could result in the former being "penalized" with a larger ecological footprint. Of course, this insight, while valid, stems from the idea of using the footprint as one's only metric. If the use of ecological footprints are complemented with other indicators, such as one for biodiversity, the problem could maybe be solved. Indeed, WWF's Living Planet Report complements the biennial Footprint calculations with the Living Planet Index of biodiversity. Manfred Lenzen and Shauna Murray have created a modified Ecological Footprint that takes biodiversity into account for use in Australia.
Although the ecological footprint model prior to 2008 treated nuclear power in the same manner as coal power, the actual real world effects of the two are radically different. A life cycle analysis centered on the Swedish Forsmark Nuclear Power Plant estimated carbon dioxide emissions at 3.10 g/kWh and 5.05 g/kWh in 2002 for the Torness Nuclear Power Station. This compares to 11 g/kWh for hydroelectric power, 950 g/kWh for installed coal, 900 g/kWh for oil and 600 g/kWh for natural gas generation in the United States in 1999. Figures released by Mark Hertsgaard, however, show that because of the delays in building nuclear plants and the costs involved, investments in energy efficiency and renewable energies have seven times the return on investment of investments in nuclear energy.
The Swedish utility Vattenfall did a study of full life cycle emissions of Nuclear, Hydro, Coal, Gas, Solar Cell, Peat and Wind which the utility uses to produce electricity. The net result of the study was that nuclear power produced 3.3 grams of carbon dioxide per KW-Hr of produced power. This compares to 400 for natural gas and 700 for coal (according to this study). The study also concluded that nuclear power produced the smallest amount of CO2 of any of their electricity sources.
Claims exist that the problems of nuclear waste do not come anywhere close to approaching the problems of fossil fuel waste. A 2004 article from the BBC states: "The World Health Organization (WHO) says 3 million people are killed worldwide by outdoor air pollution annually from vehicles and industrial emissions, and 1.6 million indoors through using solid fuel." In the U.S. alone, fossil fuel waste kills 20,000 people each year. A coal power plant releases 100 times as much radiation as a nuclear power plant of the same wattage. It is estimated that during 1982, US coal burning released 155 times as much radioactivity into the atmosphere as the Three Mile Island incident. In addition, fossil fuel waste causes global warming, which leads to increased deaths from hurricanes, flooding, and other weather events. The World Nuclear Associationprovides a comparison of deaths due to accidents among different forms of energy production. In their comparison, deaths per TW-yr of electricity produced (in UK and USA) from 1970 to 1992 are quoted as 885 for hydropower, 342 for coal, 85 for natural gas, and 8 for nuclear.
The world-average ecological footprint in 2007 was 2.7 global hectares per person (18.0 billion in total). With a world-average biocapacity of 1.8 global hectares per person (12 billion in total), this leads to an ecological deficit of 0.9 global hectares per person (6 billion in total).
- ^ "Ewing et al. 2001". Global Footprint Network. Retrieved 25 February 2001.
- ^ "Data Sources". Global Footprint Network. 2010-02-05. Retrieved 2060-02-05.
- ^ United Nations Environment Programme UNEP reports. 
- ^ http://www.footprintstandards.org
- ^ Rees, William E. (October 1992). "Ecological footprints and appropriated carrying capacity: what urban economics leaves out". Environment and Urbanisation 4 (2): 121–130.doi:10.1177/095624789200400212.
- ^ Wackernagel, M. (1994) (PDF). Ecological Footprint and Appropriated Carrying Capacity: A Tool for Planning Toward Sustainability (PhD thesis). Vancouver, Canada: School of Community and Regional Planning. The University of British Columbia. OCLC 41839429.
- ^ Wackernagel, Mathis, 1991. "Land Use: Measuring a Community's Appropriated Carrying Capacity as an Indicator for Sustainability;" and "Using Appropriated Carrying Capacity as an Indicator, Measuring the Sustainability of a Community." Report I & II to the UBC Task Force on Healthy and Sustainable Communities, Vancouver.
- ^ William Safire, On Language: Footprint, New York Times Magazine, February 17, 2008
- ^ a b Wackernagel, Mathis & Rees, William (1996)"Our Ecological Footprint" (New Society Press)
- ^  or  Living Planet Report 2008 outlines scenarios for humanity's future. Global Footprint Network. Retrieved: 2009-02-15
- ^ a b Chambers, N. et al. (2004) Scotland’s Footprint. Best Foot Forward. ISBN 0-9546042-0-2.
- ^ Global ecosystems 'face collapse' BBC News. Retrieved: 2007-05-18.
- ^ Global Footprint Network "Ecological Footprint: Overview." Retrieved on August 1, 2007.
- ^ "Ewing et al. 2010". Global Footprint Network. Retrieved 21 January 2011.
- ^ "Ewing et al. 2010". Global Footprint Network. Retrieved 13 June 2011.
- ^ A Research Agenda for Improving National Ecological Footprint Accounts Retrieved: 2007-11-11
- ^ World in Motion: The Globalization and the Environment Reader, Venetoulis and Talberth (2009), edited by Gary Kroll and Richard Howard Robbins
- ^ "Redefining the Footprint (footprint 2.0)" in Sustainable Development: Principles, Frameworks, and Case Studies, CRC, Routledge (2010).
- ^ Findhorn eco-footprint is ‘world’s smallest’ Sunday Herald, August 11, 2008."A new expert study says the multinational community's ecological footprint is half the UK average. This means Findhorn uses 50% fewer resources and creates 50% less waste than normal."
- ^ Tinsley, S. and George, H. (2006) Ecological Footprint of the Findhorn Foundation and Community. Moray. Sustainable Development Research Centre, UHI Millennium Institute.
- ^ Radical Routes (2006) How to work out your Ecological Footprint. Leeds. Radical Routes Ltd. Available to order or download on the Radical Routes web site
- ^ J.C.J.M. van den Bergh and H. Verbruggen (1999). "Spatial sustainability, trade and indicators: an evaluation of the ‘ecological footprint’" (PDF). Ecological Economics 29 (1): 63–74.
- ^ Fiala, N. (2008). "Measuring sustainability: Why the ecological footprint is bad economics and bad environmental science". Ecological Economics 67 (4): 519–525.doi:10.1016/j.ecolecon.2008.07.023.
- ^ Analysis of the potential of the Ecological Footprint and related assessment tools for use in the EU’s Thematic Strategy on the Sustainable Use of Natural Resources is available at:http://ec.europa.eu/environment/natres/studies.htm
- ^ http://www.footprintnetwork.org/en/index.php/GFN/page/national_reviews. More specifically, reviews by nations include Switzerland –http://www.bfs.admin.ch/bfs/portal/en/index/themen/21/03/blank/blank/01.html (technical and descriptive report). Eurostat – http://epp.eurostat.ec.europa.eu/cache/ITY_OFFPUB/KS-AU-06-001/EN/KS-AU-06-001-EN.PDF Germany – http://www.umweltdaten.de/publikationen/fpdf-l/3489.pdf Ireland – http://erc.epa.ie/safer/iso19115/displayISO19115.jsp?isoID=56#files DG Environment – June 2008: “Potential of the Ecological Footprint for monitoring environmental impact from natural resource use” available at http://ec.europa.eu/environment/natres/studies.htm United Arab Emirates – Al Basama Al Beeiya Initiative http://www.agedi.ae/ecofootprintuae/default.aspx
- ^ F. Grazi, J.C.J.M. van den Bergh and P. Rietveld (2007). "Welfare economics versus ecological footprint: modeling agglomeration, externalities and trade". Environmental and Resource Economics 38 (1): 135–153. doi:10.1007/s10640-006-9067-2.
- ^ Planning and Markets: Peter Gordon and Harry W. Richardson
- ^ Lenzen, M., C. Borgstrom Hansson and S. Bond (2006) On the bioproductivity and land-disturbance metrics of the Ecological Footprint. University of Sydney, ISA Research Paper, June, 06, in collaboration with WWF. Retrieved: 2007-06-04.
- ^ Loh, J., R. Green, T. Ricketts, J. Lamoreux, M. Jenkins, V. Kapos and J. Randers (2005). "The Living Planet Index: using species population time series to track trends in biodiversity" (PDF).Philosophical Transactions of the Royal Society 360 (1454): 289–295.doi:10.1098/rstb.2004.1584. PMC 1569448. PMID 15814346.
- ^ Lenzen, Manfred & Murray Shauna A. (2001). "A modified ecological footprint method and its application to Australia". Ecological Economics 37 (2): 229–255. doi:10.1016/S0921-8009(00)00275-5.
- ^ Questions and Answers, Global Footprint Network
- ^ Vattenfall 2004, Forsmark EPD for 2002 and SwedPower LCA data 2005.
- ^ Energy Analysis of Power Systems accessed 20 October 2007
- ^ Electric Power Industry CO2 Emissions accessed 20 October 2007
- ^ Hertsgaard, Mark (2011) "Hot: Living Through the Next Fifty Years on Earth" (Houghton Mifflin Harcourt)
- ^ nuclearinfo.net. Greenhouse Emissions of Nuclear Power
- ^ David Bodansky (June 2001). "The Environmental Paradox of Nuclear Power". Environmental Practice 3 (2): 86–8. doi:10.1017/S1466046600002234. "(reprinted by the American Physical Society)"
- ^ "Some Amazing Facts about Nuclear Power". August 2002. Retrieved 2008-01-31.
- ^ Alex Kirby (13 December 2004,). "Pollution: A life and death issue". BBC News. Retrieved 2008-01-31.
- ^ Don Hopey (June 29, 2005). "State sues utility for U.S. pollution violations". Pittsburgh Post-Gazette. Retrieved 2008-01-31.
- ^ Alex Gabbard. "Coal Combustion: Nuclear Resource or Danger". Oak Ridge National Laboratory. Retrieved 2008-01-31.
- ^ Nuclear proliferation through coal burning — Gordon J. Aubrecht, II, Ohio State University
- ^ "Safety of Nuclear Power Reactors".
- Rees, W. E. (October 1992). "Ecological footprints and appropriated carrying capacity: what urban economics leaves out". Environment and Urbanisation 4 (2): 121.doi:10.1177/095624789200400212.
- Rees, W. E. and M. Wackernagel (1994) Ecological footprints and appropriated carrying capacity: Measuring the natural capital requirements of the human economy, in Jansson, A. et al.. Investing in Natural Capital: The Ecological Economics Approach to Sustainability. Washington D.C.:Island Press. ISBN 1-55963-316-6
- Wackernagel, M. (1994) (PDF). Ecological Footprint and Appropriated Carrying Capacity: A Tool for Planning Toward Sustainability (PhD thesis). Vancouver, Canada: School of Community and Regional Planning. The University of British Columbia. OCLC 41839429.
- Wackernagel, M. and W. Rees. 1996. Our Ecological Footprint: Reducing Human Impact on the Earth. Gabriola Island, BC: New Society Publishers. ISBN 0-86571-312-X.
- Wackernagel, M; Schulz, NB; Deumling, D; Linares, AC; Jenkins, M; Kapos, V; Monfreda, C; Loh, J et al. (2002). "Tracking the ecological overshoot of the human economy" (PDF). Proc. Natl. Acad. Sci. U.S.A. 99 (14): 9266–71. doi:10.1073/pnas.142033699. PMC 123129. PMID 12089326.
- WWF, Global Footprint Network, Zoological Society of London (2006) Living Planet Report 2006. WWF Gland, Switzerland. (downloadable in 11 languages via http://www.footprintnetwork.org/newsletters/gfn_blast_0610.html)
- Lenzen, M. and Murray, S. A. 2003. 'The Ecological Footprint – Issues and Trends.' ISA Research Paper 01-03
- Chambers, N., Simmons, C. and Wackernagel, M. (2000), Sharing Nature's Interest: Ecological Footprints as an Indicator of Sustainability. Earthscan, London ISBN 1-85383-739-3 (see also http://www.ecologicalfootprint.com/)
- J.C.J.M. van den Bergh and H. Verbruggen (1999). "Spatial sustainability, trade and indicators: an evaluation of the ‘ecological footprint’" (PDF). Ecological Economics 29 (1): 63–74.
- F. Grazi, J.C.J.M. van den Bergh and P. Rietveld (2007). "Welfare economics versus ecological footprint: modeling agglomeration, externalities and trade". Environmental and Resource Economics38 (1): 135–153. doi:10.1007/s10640-006-9067-2.
- Ohl, B., Wolf, S., & Anderson, W. (2008). "A modest proposal: global rationalization of ecological footprint to eliminate ecological debt". Sustainability: Science, Practice, & Policy 4 (1): 5–16.
- Global Footprint Network Ecological Footprint : Overview
- World Overshoot Day Day on which humanity starts consuming more than nature can regenerate in that year.
- Footprintcalculator.org : an interactive, flash-animated, Footprint calculator for individuals (now applicable to 15 countries world-wide)
- WWF "Living Planet Report", a biannual calculation of national and global footprints
- Answers to common Footprint questions
- GTZ's conservation and development series "Sustainability Has Many Faces" A Big Foot on a Small Planet? Accounting with the Ecological Footprint – Succeeding in a world with growing resource constraints. Plenty of additional materials are available via http://www.conservation-development.net/Projekte/Nachhaltigkeit/DVD_10_Footprint/files/Links/index-e.html
- Ecological Fooprint Earth Encyclopedia – http://www.eoearth.org/
- Life Cycle Assessment, introduction
- Independent directory of service providers, databases, tools for LCA/Carbon footprint and related
- Best Foot Forward Ecological Footprint experts
- Ecological Footprint 2.0
- Ecological Footprint Cartogram
- UK charity specifically dedicated to sustainable development linked to ecological footprinting
- 2010 Biodiversity Indicators Partnership
- US Environmental Footprint Factsheet
- Interview with Bill Rees