Ecological footprint


The ecological footprint is the most widely used supply-and-demand accounting method for determining the rate of consumption of the planet's natural resources (biocapacity) by humans. Since 1961, ecological footprint calculations have been created every two years and include: carbon footprint, climate change, and the recent calculation data of global water footprint.

A carbon footprint is the calculation method for determining the level of carbon dioxide emissions (greenhouse gases) impacting the world's ecology.

Climate change refs to any long-term changes in global weather patterns (including temperature, wind, and precipitation) due to natural processes or human activities. Global warming, considered part of climate change, refers to an average temperature increase of the lowest layer of Earth's atmosphere.

Global water footprint is a method of calculating the amount of water required to produce the goods and services consumed by humans, crop irrigation, and industrial water demand.

The ecological footprint indicates how many Earths are needed to provide for the current needs of its inhabitants and projects possible future needs based on current global data. According to 2008 data, the Earth has 4.4 global acres of productive space per person; however, each person uses an average of 5.4 global acres worth of resources.

In 1987, the Brundtland Report was released by the United Nation's World Commission on Environment and Development. This report was the first extensive global look into the planet's general health, which brought the scientific community's concerns to the forefront. The report proposed that there are limits to the planet's resources and its ability to absorb human waste products. The report focused on global food production and distribution, ecological preservation, and industrial and urbanization impact.

The term "sustainable development" was introduced and referred to the planet's ability to continue meeting the needs of the current world population, without exhausting the planet's ability to meet future needs. Until this point, it was assumed that the Earth would always be able to provide adequate resources for its population.

In 1992, the term ecological footprint was defined in the academic publication of a PhD thesis paper entitled "Ecological Footprint and Appropriated Carrying Capacity: A Tool for Planning Toward Sustainability," written by Mathis Wackernagel, a graduate student taught by William Rees at the University of British Columbia in Vancouver, Canada. Ecological footprint referred to the process of calculating the impact that a city, individual, industry, nation, or region has on the Earth. This calculation process has become the standard for evaluating the relative current health status of the planet and is the foundation method of the Global Footprint Network's assessments.

The United Nation's (UN) 1992 Earth Summit in Rio de Janeiro addressed the global impact of economic development and environmental protection. This meeting produced two international treaties and Agenda 21. In 1993, the United States adopted the principles of Agenda 21, which promoted the concept of sustainable use and development of the world's resources when President Bill Clinton issued his Executive Order 12852.

In 2003, the Global Footprint Network was formed. Using statistics from the UN, the organization calculated the ecological global footprint for each year since 1961. The focus of environmental experts on ecologically sustainable resources stems from the realization that the world's present demand on its natural resources is nearly one-third more than the planet can currently deliver.


Ecological footprint analysis: Ecological footprint is a calculation method used to measure how much productive land and water an individual, industry, region, or country uses to support itself and dispose of its wastes. It is a complex calculation method comprised of the amount of the planet's biologically productive land and water, the type of housing and transportation used by its population, and the manufacture and use of specific good and services. Data from more than 90 partners in six continents contribute to the local and regional information used in the calculations.

Within the ecological footprint's big picture is an estimation of the relative level of carbon dioxide waste production and emission (the carbon footprint), global climate change (global warming), and the newer calculation of global usable water (global water footprint).

The unit of measure used in these calculations is the "global hectare," which determines the world's average of all productive land, inland water, and ocean resources in a given year. A global hectare is equal to one hectare (2.47 acres) of biologically productive land or water. Currently, the Earth has 11.2 billion hectares, or about one-quarter of the planet's surface, available as productive space. The amount of usable space may change from year to year due to land use, pollution, and weather patterns.

The most productive areas are cropland, developed land, grazing land, inland water, and jungle/forests. The least productive are deserts and extreme, ice-covered areas. The complex global footprint calculations concentrate on productive areas and assume that all available productive land and water is available for human use.

The carbon footprint is a component of the larger ecological footprint. The carbon footprint measures the level of carbon dioxide emission. Carbon dioxide is a major waste product resulting from transportation methods, fossil fuel energy, and industrial production. It is estimated that the carbon footprint of the Earth's population comprises more than 50% of the overall ecological footprint.

Ecological footprint by country: More industrialized the geographical areas release more carbon dioxide into the atmosphere. Since 2005, large industrialized countries, such as the United States and China, have produced most of the Earth's carbon dioxide emissions. The current carbon footprint for the United States shows that 36.2% of its carbon dioxide emissions are from home energy, 44.3% from driving or flying, 15.1% from food and diet choices, and 4.4% from recycling and waste control.

Many experts estimate that the world population will need to reduce its carbon dioxide emissions by 60-80% in order for Earth's resources to sustain its growing population. The calculation of various other greenhouse gases is not included in the ecological footprint data. Sufficient evidence is lacking about the long-term implications of lesser greenhouse gases and how the planet may absorb these materials.

Climate change causes: Climate change refs to any long-term changes in global weather patterns (including temperature, wind, and precipitation) due to natural processes or human activity. Experts suspect that humans play a large role in climate change due largely to the increased dependency on fossil fuels, toxic gas emissions, and the destruction of natural climate mediators, such as forests and jungles. Recent episodes of extreme climatic heat and cold, lethal hurricanes, rising ocean levels, and unusual outbreaks of tropical diseases have lead many experts to call for changes in energy fuel sources, stronger industrial and automotive emission controls, and international cooperation.

Global water footprint concept: Global water footprint is a component within the ecological footprint and reflects the amount of global useable water available to the world population. Water amounts withdrawn from lakes, aquifers, and rivers used for irrigating crops, processing industrial products, and household use are monitored, as well as usable levels of rainfall. Also, the amount of water required for a nation's imported goods, which are manufactured in another country, is calculated. According to the Global Footprint Network's (GFN) 2008 report, the world's average water footprint is 1.24 million liters (or half of an Olympic sized swimming pool) per person per year.

As of the 2008 GFN report, nuclear power energy production was no longer included in the calculations, as the agency states the risks of this type of energy production are "not easily expressed in terms of biocapacity." In addition, the impact of toxic waste matter (such as polychlorinated biphenyl/PCBs, dioxins, and plutonium), soil erosion, deforestation, and saltwater invasion of fresh water supplies are not included in the global footprint's assessments. Similarly, no designated land or water mass is allocated for the needs of wild species. All viable land and water masses are considered useable for human support.

The necessary international data are supplied to the GFN each year as crops, weather, consumer usage, and wastes change. Therefore, ecological footprints may improve or worsen depending on the extent of natural resources use and level of waste produced.

Ecological overshoot: In 1961, according to the GFN's first estimation of human demand on the Earth, almost all of the countries in the world had more than enough capacity to meet their needs. By 2005, however, the data showed that many countries could only meet their population's needs through importation of goods.

Regions or nations with an ecological footprint larger than their biocapacity, or their area's ability to regenerate its resources, are considered to be in ecological "overshoot." Overshoot is the state of being in ecological debt.

Overall, it is estimated that the Earth is in overshoot, as it is currently being required to provide 30% more than its yearly regenerative capacity, or the equivalent of one and a third Earths. On September 23, 2008, the planet reached this state of overshoot three months short of what the earth could regenerate in twelve months. This may occur as trees are cut before they can regrow, fish and mammals are hunted faster than they can reproduce, and the waters of the planets are overused or mismanaged.

According to the 2008 GFN report, this overshoot may be due to major increases in world population numbers and its increase in consumption of products, resources, and energy. In Africa the population has tripled in 40 years, and the ability of their region to support this population level has decreased by 67%. In China, the individual ecological footprint and the population level has doubled since 1961. The report predicts that if the world continues at this pace, two planets would be needed to fulfill the demand for resources by the early 2030s.

Ecological methodology: New methods of data calculation are now being developed as more nations realize the importance of limiting the negative impact on their sustainable resources and the interdependence of their actions with those of other nations.

Many individuals, industries, and nations are being educated with literature, online calculators, and television programming about ways to decrease their ecological footprints.

Various web-based interactive calculators are available to assist individuals in becoming aware of their specific carbon and water footprints and collectively decrease their demand on the planet's limited resources. Depending on the calculator, areas of improvement may be determined by filling in personal usage data, such as the number of people in a household, the source of heating energy, the energy efficiency of interior and exterior lighting and appliances, the frequency of auto travel, mileage driven, car model and year, use of public transportation, food preferences and packaging, clothing, furniture, and electronic purchases, recycling and composting habits, and recreation choices. Many sites offer suggestions and tips for reducing the carbon footprint of the consumer.


Theory of ecological overshoot: The Living Planet Report, a collective report from the World Wildlife Fund (WWF), the Zoological Society of London, and the Global Footprint Network suggests that most of the world's population is living in nations that have exceeded their country's biological capacity. This state of excessive use is referred to as "overshoot." The United States, China, and India have the largest national ecological footprints. Brazil, Russia, Argentina, Australia, and Canada are also heavy users of the planet's resources. These eight nations contain more than half of the world's biocapacity, or its ability to produce usable resources. Unequal distribution of natural resources leaves some areas of the world, such as Africa, struggling to provide for its inhabitants.

According to the WWF, the global ecological footprint was 17.5 billion global hectares (one hectare is 2.47 acres) in 2005, but the total productive area, or biocapacity, was only 13.6 billion global hectares.

As population density and economic affluence increase, a country's carbon footprint also increases. In 2005, the United States and China had the largest total ecological footprint, each using 21% of the Earth's biocapacity. These two countries also had the largest carbon footprints.

Many experts suggest that almost three-quarters of the United State's ecological footprint is from carbon dioxide, resulting from energy consumption. The burning of fossil fuels, such as coal, oil, and natural gas made up almost 45% of the global ecological footprint in 2005. Experts suspect this practice has led to climate alterations.

According to the U.S. Environmental Protection Agency (EPA), climate change refers to any significant change in Earth's temperature, precipitation, and/or wind which is sustained for decades or longer. Global warming is considered part of climate change.

Global warming refers to an average increase in the Earth's surface and lower atmospheric temperatures, which impacts the world's climatic patterns. Global warming may occur from natural sources, such as an increase in solar temperature, or more recently from large areas of deforestation (such as in the Amazon), and from man-made "greenhouse gases." Greenhouse gases are comprised of emissions from fossil fuel use; carbon dioxide being the major constituent of these gases which are released into the atmosphere. The build up of these gases prevent the normal escape of heat from the Earth's surface into space. This alteration in the planet's ability to regulate its temperature causes long term changes in the environment, such as glacier melting and climate variations.

Evidence of ecological overshoot: The result of the greenhouse gases trapping the Earth's heat has, according to National Oceanographic and Atmospheric Administration (NOAA) data, increased the planet's land temperature from 1.2 to 1.4 degrees Fahrenheit in the past 100 years. The eight warmest years on record have all occurred since 1998. The 2004-2005 climatic season was the most meteorologically violent in recent history.

Experts predict that the average land surface temperature of Earth could increase another 3.2 to 7.2 degrees Fahrenheit by the end of this century. Rainfall events may shift to heavier rains in the tropics, with mid-continental U.S. areas, Africa, and southern Asia experiencing drought. Snow and sea ice have decreased by 10% since 1966, and are projected to continue to decrease in the northern parts of the planet, with the ongoing retreat of glaciers and ice caps. Sea levels may rise from 0.18 to 0.59 meters.

The NOAA, Scripps Institution of Oceanography, Lawrence Livermore National Lab, and the United Kingdom's Hadley Center have demonstrated that the oceans of the world have been warming for more than 50 years, especially along the equator. Expert consensus suggests that this temperature increase is due to the effects of greenhouse gases. Recent abnormally large red algae blooms in coastal areas of the United States have been linked to the increase in ocean water temperature.

However, the Global Footprint Network suggests that greenhouse gases and the carbon footprint only indicate part of the problem. As populations increase, even less resources are available to meet the needs of the individual, and destructive land and industrial practices increase, thereby accelerating the decline of the region. Despite the lengthening of crop growing seasons due to the increase in temperature and the resulting decrease in frost events, the planet may suffer from uneven distribution of rainfall and potential resulting catastrophic crop failures.

Recent studies by the Ecological Society of America on the depletion of natural resources and the pollution of essential air and water, led to the realization that these complex ecological systems overlap a multitude of issues, including the need to maintain wildlife biodiversity, contain and treat world health issues, balance food and drinkable water shortages, and prevent catastrophic climate changes due to human influences.

The Intergovernmental Panel on Climate Change (IPCC), the World Meteorological Organization (WMO), and the United Nation's Environmental Program (UNEP) are providing scientific advice to international government policy makers. In 2007, meeting topics included the buildup of greenhouse gases, prediction of climate change impact, and policy discussion.

The Economic and Social Council of the United Nation's November 2008 report entitled, "Major groups priorities for action in agriculture, rural development, land, drought, desertification, and Africa," outlines a vast web of interconnected ecological issues that relate to policy opinions and proposed solutions for global governments. Current problem areas are female farmer's legal rights, child labor, the access rights of indigenous people, trade unions, local governments, industries, farmer education, food source securities, and equitable rights of water access.


The planet's health has a significant impact humans and this relationship has become a topic of concern within the global community.

The World Health Organization's (WHO) report entitled, "Primary Health Care Now More Than Ever," stated that recent health problems are dynamic and have been largely unexpected. The WHO has attributed an alarming rise in childhood asthma, transmission of once-considered regional communicable diseases, such as Dengue Fever, and geographical food shortages to negative changes in the world's environmental health.

Most world health and environmental experts agree that as using the planet's resources faster than they can be replenished may have negative effects on the health of humans, wild species, and vegetative crops.

The negative change in the planet's health is discussed in the Living Planet Index (LPI), a 2008 comprehensive assessment of wild species and the natural ecosystems of the world. According to the LPI, wild species and their environment are threatened by habitat loss, especially from farming, over-fishing or hunting, pollution, invasive species that take away valuable resources from native species, and climate change. All of these threats may be the direct result of human demand for goods and services. The greatest current threat is to the polar and coastal regions, including adjacent coral reefs.

According to the LPI, the world's terrestrial vertebrate population has declined 33% from 1970 to 2005 due to agriculture pressure, logging, and hunting. The Marine Index shows a 14% decrease in fish species from 1970 to 2005, due to rising sea temperatures, over-fishing, use of inappropriate fishing techniques (such as trawling), and pollution. The rapid decline of coral reefs due to bleaching and disease are believed to be due to rising sea temperatures. Inland water fish species have decreased 35% from 1970 to 2005 due to over-fishing, invasive species competition, dams, and other water diversions.

The Tropical Forest Index shows a decline of 60% in animal populations due to deforestation in primary regions of the world, such as the Amazon. Experts fear that if the decline continues at the current rate, the earth's water purification and climate regulatory systems, which depend on large tracts of jungle and forested areas, will be compromised.

Dryland ecosystems, such as deserts, savannahs, and tropical dry woodlands, are under tremendous pressure as they are home to an estimated 2 billion people who live directly in these areas. Grasslands are crucial to the nutrient value of the earth's environment. Signs of the problem are reflected in a 36% decline in grassland antelopes, an animal important for many predator species.

Environmentalists suggest that the disappearances of entire species, such as the mysterious disappearance of the golden toad (Bufa periglenes) of Costa Rica, the Northern white rhino of North-Central Africa, and the salga antelope (Salga tatarica), which has been hunted nearly to extinction in the last 40 years, indicate the level of ecological disorder.

The Bird Index section of the LPI shows a 20% decline in 2,185 surveyed populations of 895 species of tropical and marine birds, due to habitat loss, invasive species, hunting, and pollution.

The Mammal Index shows a 20% decrease since 1970 in 1,161 populations of 355 species, mostly in the tropical areas of Africa and Southeast Asia, where bushmeat is a source of protein and income.

Other species under extreme pressure are the mauritius kestrel (Falco punctatus), the red howler monkey (Alouatta seniculus), grey tree frog (Hyla versicolor), loggerhead turtle (Caretta caretta), the hippopotamus (Hippopotamus amphibius), the diamondback terrapin (Malaclemys terrapin), the southern right whale (Eubalaena australis), and the coho salmon (Oncorrhynchus kisutch).

As the world's population increases and resources dwindle, available products and services will require more extensive land and water use, and expensive importation of unavailable goods. The poorer regions of the planet, which are currently unable to meet the needs of its populations, may become increasingly in ecological debt. Destruction of jungle and forest land for agriculture, over-fishing of natural species, and atmospheric release of greenhouse gases will further endanger the ecological condition of the entire planet.

As resources decrease, political tensions and social unrest may increase. For instance, multiple regional political conflicts, as has been seen in Africa over the past decade, have erupted when food and water become scarce. As residents are displaced from their homeland due to crop and resource failure, many migrate to neighboring countries where additional pressure is placed on that new region to provide for both its original and newly arrived inhabitants.

International arguments over water rights have occurred in many arid regions where major rivers and other water sources cross national borders.


Projections for the future state of the planet include: continued world population growth and demand; atmospheric carbon dioxide exceeding 500 parts per million between years 2050 and 2100 ( a greater level than anytime in the past 420,000 years); widespread climate change; loss of inhabitable land, especially in island nations such as in the Pacific Ocean; extinction of known species of plants and animals; increase of tropical diseases born by people and insects moving into warmer geographical areas; and degradation of water quality and availability.

More accurate and uniform methods of data collection, efficient reporting of current data, and standardized calculation methods of the earth's state of health are priorities among leading environmental experts.

Current data could be used to create models to anticipate future areas of crises, and begin early intervention, instead of waiting until an area is already challenged with ecological distress.

The global water footprint could be a tool to assist in the equitable distribution of usable water resources in areas which are suffering deficits.

Marine fishery organizations are working toward maintaining a sustainable level of fish species through international cooperation. Conservation research continues to work to understand the impact of rising sea temperature on marine fish and mammal health and disease.

Populations or nations with biological reserves that are using less than its maximum resources are being encouraged to set aside these resources for wild species or for use in future situations.

The goal of the Global Footprint Network, U.S. Environmental Protection Agency (EPA), National Oceanic and Atmospheric Administration (NOAA), and other scientific agencies is for increased consultation during the creation of governmental policy, industrial techniques, and corporate awareness.

In the United States, consumer education and financial incentive programs, such as tax rebates, are being implemented to encourage a decrease in the country's carbon footprint.

Choosing ecologically sound products and behaviors, called "going green," is a way for an individual and community to decrease its use of toxic chemicals, energy drain, and fresh water waste, and therefore, reduce the size of its carbon footprint. Recycling of plastic, glass, newsprint, cardboard, and aluminum is encouraged for residential homes and commercial facilities, in order to decrease the level of greenhouse gases released during those product's manufacture. Fuel-efficient and nonpolluting automobile choices, car-pooling, and decreasing air travel are other ways consumers can personally reduce the accumulation of greenhouse gases. Choosing "green" goods, packaging, clothing, and energy-efficient appliances may also decrease a person's carbon footprint.

Many energy providers, appliance manufacturers, and other green-conscious industries provide free environmentally friendly information for the consumer.

At the International level, cooperation will be required in order to rebalance the planet's biocapacity. This will involve large global footprint reductions through new non-polluting technologies for energy and industrial production, changes in infrastructure building codes to promote green operation, farming with sustainable agricultural methods, prevention deforestation, fresh water conservation methods, international fishing restrictions, and reasonable global reallocation of resources.


This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (

  • Environmental Protection Agency (EPA).
  • Global Footprint Network.
  • Hoegh-Guldberg O, Mumby PJ, Hooten AJ, et al. Coral reefs under rapid climate change and ocean acidification. Science. 2007 Dec;318(5874):315-6. View abstract
  • Kitzes J, Peller A, Goldfinger S, et al. Current Methods for Calculating National Ecological Footprint Accounts. Science for Environment & Sustainable Society, 2007; Vol 4, No 1.
  • National Oceanic and Atmospheric Administration (NOAA).
  • Natural Standard: The Authority on Integrative Medicine.
  • Pew Center on Global Climate Change.
  • Savitz J, Harrould-Kolief E. Ecological Society of America (ESA). The Ocean's Acid test: can our reefs be saved? Frontiers in Ecology and the Environment. 2008 Dec;6(10):515-515.
  • Schwartz BS, Parker C, Glass T, et al. Global Environmental Change: What Can Health Care Providers and the Environmental Health Community Do About it Now? Environ Health Perspect. 2006 Dec;114(12):1807-1812. View abstract
  • United Nations. Economic and Social Council 2008.
  • United Nations Environment Programme (UNEP). Convention on Biological Diversity 2005.
  • Wackernagel M, Kitzes J, Loh j, et al. Shrink and Share: humanity's present and future Ecological Footprint. Philos Trans R Soc Lond B Biol Sci. 2008 Feb 12;363(1491):467-75. View abstract
  • World Health Organization (WHO).
  • World Wildlife Fund (WWF).

Copyright © 2011 Natural Standard (
We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Show Comments ()
Voting Booth
Are you still optimistic about the future of South Africa?
Please select an option Oops! Something went wrong, please try again later.
Yes, I believe the potential is still there
19% - 782 votes
No, I feel we cannot reverse the damage that has been done
49% - 2069 votes
I will only be able to say after the 2024 elections
32% - 1353 votes
Rand - Dollar
Rand - Pound
Rand - Euro
Rand - Aus dollar
Rand - Yen
Brent Crude
Top 40
All Share
Resource 10
Industrial 25
Financial 15
All JSE data delayed by at least 15 minutes Iress logo
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.