Sustainable Indicators

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Sustainable indicators are methods aimed at measuring and quantifying the sustainability degree of a society, process or development. For a long time the GDP (growth domestic production) indicator, the total of economical activity divided by population has been the only indicator to track well being. Economic growth (increase in GDP) was synonymous with increase in well being. However the GDP fails to account for health and environmental damage, resource depletion and social well being and thus fails to stand as a sole number that summarizes and predicts the progress of society and its state of sustainability. In the last several years we have seen a global endeavor to come up with new indicators that shed light on human progress from all different angles in spite of the difficulties of defining sustainability and the challenge of integrating measures from different fields such as economics, social and environmental (the pillars of sustainability). Usually indicators measure only one pillar of the three. The Stiglitz-Sen-Fittousi report commissioned by french president Sarkozy is a first attempt to summarize the current knowledge of indicators and suggest new methodologies about tracking societal progress and well being. Some indicators are mentioned below.

The human development index

Compiled by Economist Mahbub ul Haq and other researchers in 1990 the human development index combines health (life expectancy), education (literacy) and standard of living (GDP) to come up with a single number between 0 and 1 that presents a country's state of development. For more look in here.

Ecological Footprint

Ecological footprint Analysis (EFA), introduced by Rees and Wackernagel in the 1990s [1], is a measure of the anthropogenic demand on natural resources. EFA is measured in units of area (global hectares), which translates into the area an individual/business/city/nation/etc exploits resources to maintain a certain lifestyle and to absorb its wastes.

The ecological footprint indicator tracks the appropriation of resources and the generation of waste using a single unit of area for six types of lands. Resource and waste are transformed to land area by dividing the demand for a resource (e.g. tons) by the yield per hectare(tons/hectare) and the waste (tons) with the absorptive capacity per hectare.

Ecological Footprint Analysis = annual demand/annual yield

EFA calculates the aggregated demand on resources in a specific location and transforms them into global average area units (known as global hectares). The global hectares are defined as bioproductive hectares with world average bioproductivity. Transforming the land area into global hectares is done by dividing the location specific yield per hectare with the average global yield per hectare (using the yield factors); and using the equivalence factor, which marks the relative productivity of each land type (e.g., crop land is the most productive land and therefore needs to be re-weighted accordingly to arrive to the average productivity area).

Ecologcial Footprint Analysis = (annual demand/national yield in annual tonnes per ha)*Yield Factor*Equivalence factor

This is done using six types of land, crop land, grazing land, urban land, forest for timber etc, forest for sequestration of carbon, and fishing ground. Except fishing ground and build-up land each land use type is calculated as a sum of the variety of products produced on that specific land type.

Biocapacity represents the biosphere's ability to provide food' livestock and resources and sequester CO2 It is the total amount of bioproductive land divided. Biocapacity is calculated as the area of each land type in global hectares (thus requiring the 2 weighting coefficients):

Biocapacity = Area*Yield Factor* Equivalence Factor

The Yield factor takes into account the differences in yields for a given land type in a specific location. It is calculated by dividing the national yield with the average yield for the same land time. The yield factor of build up land is taken to be the same as crop land since urban areas are usually constructed on or near agricultural areas. Equivalence factors mark the relative productivity of a specific land type. For 2005 crop-land had a 2.64 value indicating that crop land had more than double the average global productivity.

Comparing the Biocapacity to The EFA for a person/community/nation can reveal a deficit in natural reserves when the subtraction of the terms is negative (Global overshoot), implying a dwindling in Natural capital and ecosystem collapse in the long run; when the subtraction is positive it implies sustainability, that is the demand for ecological services is not higher than Nature's generation capabilities of these services.

Interregional Ecologcial footprint

In a globalized world where trade is an important factor the "import" and "export" of environmental impacts between countries is commonplace, since the ecological footprint of a nation must include sustainable or unsustainable practices in other regions of the world where their merchandises are being imported from. The Interregional ecology footprint, developed by Kissinger and Rees thus develops a sustainability indicator which extends the ecological footprint from a local phenomena to the global arena, connecting between countries to the sources of their imported resources in any supporting region in the world [2].

Carbon footprint

The carbon footprint is the amount of GHG emissions emitted during the lifecycle of a product or service. Look in here for more.

Water footprint Analysis

The Water footprint Analysis (WFA), though often assumed to be a segment of the total EFA, incorporates the volume of water needed for services and/or products throughout their entire lifetime, both direct and indirect. Yet, the areal method behind EFA calculation does not incorporate the amount of water consumed directly; however full Life cycle assessments Life Cycle Assessment do contain the water used in the whole life cycle of a certain product of services. The actual water within products (even agricultural) is negligibly low compared to the water needed in their production stage. The water footprint is an indicator of water consumed with both a direct and indirect water use components. The water footprint indicator can be used to track the WFA of an individual, business, community or nation by summing the total volume of fresh water used by the individual or community both in direct or indirect fashion. The WFA of a nation is the amount of water directly consumed (divided into domestic, agriculture and industry use), plus the virtual water import (through products and services) minus the virtual water export. The water footprint concept stems from the ‘embedded water’ or ‘virtual water’ concept introduced by [3] in reference to the middle east water scarcity problem. His idea relays on the the option of importing virtual water (contrary to real water) as a way of reducing the pressure on scarce local water sources. Virtual-water has then become a 'new' water source on its own. Imported virtual water is also referred to as ‘exogenous water’, and ‘embodied water’. For instance while the direct water use of Jordan is about 1 billion cubic metre, it's virtual water imports are about 5-7 billion, thus redefining issues of water scarcity within that country in a different way [4].

The indirect water use refers to the water that is used to produce the goods and services at question. ‘Water use’ of a crop refers to the water volumes consumed (evaporated, or specifically evapotranspired) and/or polluted from the planting phase through the harvest. In the simplest way it is calculated by summing the evapotranspiration (mm/day) at a given location during the crop's life time until harvested. In agricultural products/services the total WFA can be divided into several components: green water footprint refers to evaporation of rain water from soil (available green water is the water stored in the soil as soil moisture); blue water footprint is connected to evaporation of surface runoff and fresh water lakes (blue water availability refers to ground water and lakes); and gray water is the amount of water used to dilute water pollution to acceptable clean water standards. The volume of green water and blue waters amounts to the total precipitation in a given area. To complete a full WF of a natural product the direct volume of water used in after harvesting (for instance washing) must be supplemented.

Finding WFA of sugar, coffee and tea - The average WFA of coffee is 21,000 M3/ton or 21 M3/kg and of of tea 10,400 M3/ton or 10.4 M3/kg. The water footprint of coffee and tea consumption in the Netherlands, [5]. The average sugar cane has a WF ~1500 M3/ton or 1.5 M3/kg. Look in here. 175 litres of water is needed to produce 1 kg of sugar cane. Only 11% of the sugar cane is sugar, so 0.11 kg of sugar is derived from 1 kg of sugar cane. Hence, for 1 kg of refined sugar about 1500 litres of water is needed (This doesn't include the water needed during the extraction of sugar in the production phase). So in one cup of coffee/tea......a strong coffee cup,10gr, WFA = 210 lit/cup; in a standard tea cup, 3gr, WFA = 31.2 lit/cup/ Using one spoon of sugar requires 10gr, WFA =15 lit/cup...In other words about 225 liters of water are required for you to enjoy a cup of coffee, besides of course the 1/3 liter of water in the cup itself!!

The motivation behind the formulation of WFA and the difference between WFA and ECA is summed by A. Hoekstra, who developed the WF concept [6]] "The concept of the water footprint shows similarity to the concepts of the ecological footprint and the carbon footprint. The roots and intended purposes of the three concepts differ, however . The roots of ecological footprint analysis lie in the search for an indicator that can show what proportion of the globe’s biocapacity has been appropriated. The carbon footprint was formulated later to be able to quantify the contribution of various activities to climate change. The roots of water footprint analysis lie in the exploration of the global dimension of water as a natural resource. The starting point was the discontent with the fact that water resources management is generally seen as a local issue or a river-basin issue at most. The fact that international trade affects the global pattern of water use has been overlooked. The global dimension of water resources management and the relevance of the structure of the global economy have been ignored by most of the water science and policy community [7]. In addition, the production (supply) perspective in water resources management is so dominant that it is hardly recognized that water use relates in the end to human consumption. By looking at the water use along production and supply chains, the water footprint aims to uncover this hidden link between human consumption and water use. "

World3 - Dynamical analysis of resources, pollution, population and economy

In 1972 a group of scientists from MIT sponsored by the club of Rome issued a report called 'the limit of growth'. Their work, which used a dynamical resource-human-ecology-social-economical model to examine the state of the earth in the future, predicted a social collapse in the the next century due to over exploitation of resources and increased population growth [8]. The variables of the model are population, industrial capital, pollution, and cultivated land all intertwined in complicated feedbacks, attempting to represent the connections between these entities in reality.The model describes the flow of resources and energy through the economic system and into the earth back again as wastes. The model portraits the limits to which resources can be exploited before harm to nature and man are done or before they run out. The different model runs all show that in order to avoid collapse sometime in the next century a combination of limiting population growth and consumerism as well as adapting advanced technologies are all required if the human race is to move to a sustainable existence. The introduction of the world3 model was criticized heavily for several reasons, but brought the issue of sustainability into the foreground of scientific and public debate.


  1. footprint network
  2. EF reports
  3. water footprint analysis
  4. Interregional human ecology
  5. sustainable indicators in Israel
  6. State of The USA


  1. Our Ecological Footprint: Reducing Human Impact on the Earth, M. Wackernagel and W. Rees (1996), Gabriola Island, BC: New Society Publishers. [Wacker-Rees-1996]
  2. Interregional Ecology – Resource Flows and Sustainability in a Globalizing, Meidad Kissinger (2008), Phd dissertation


  3. Virtual water: a strategic resource, global solutions to regional deficits, Allan, J.A. (1998) Groundwater 36 (4), 545–546.


  4. Footprint of Nations, Chapagain A.K. ,Hoekstra A.Y. (2004) Research Report Series No. 16


  5. The water footprint of coffee and tea consumption in the Netherlands, Chapagain, A.K., and Hoekstra, A.Y. (2007) Ecological Economics 64(1): 109-118.


  6. Water neutral: reducing and offsetting the impacts of water footprints, Hoekstra A.Y. (2008) Research Report Series No. 28


  7. Human appropriation of natural capital: Comparing ecological footprint and water, Hoekstra, A.Y. (2007) Ecological Economics 68(7): 1963-1974


  8. The Limits to Growth, 30 year update, Donnela Meadows, Dannis Meadows and Jorgen Randers (2004), Chelsea Green Pulishing Company


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