Part Two discusses the methods for accounting the Ecological Footprint, provides an application example, and shares the strengths and limitations of the Ecological Footprint Accounting for sustainability analysis.
Let’s begin Part One.
The quantity of resources required depends on the standard of living, income level, and local environmental condition. The total resources consumed by a person indicate his Footprint whereas biocapacity is the nature’s regenerative capacity.
Biologically productive land includes the area that supports human demand for food, fiber, timber; space for infrastructure; and absorbs the emitted waste.
Thus, the Ecological Footprint answers the questions: how much of our planet’s regenerative capacity do we use by quantifying the demand that human consumption and waste generation place on the biosphere.
The Ecological Footprint measures sustainability by assessing the current trends of consumption, and comparing it with the biocapacity. This helps track the consumption of natural resources and generation of waste.
Understanding and influencing consumer’s behavior and the associated environmental impacts is necessary to measure and monitor the rate of consumption and its relationship to nature’s ability to provide. It will help with planning resources and estimating generated wastes.
The Ecological Footprint measures the resources consumed and wastes generated.
Biocapacity measures the capacity of nature to absorb the wastes and generate new resources.
Ecological Footprint accounting considers the different types of land areas required to meet the human demand.
Average bioproductivity differs among various area types, as well as among countries for any given area type. For comparability across area types and countries, Ecological Footprint and biocapacity are expressed in units of world-average bioproductive area, referred to as global hectares (gha).
When a region or country is in ecological deficit, it meets demand by importing embedded biocapacity through trade, liquidating its own ecological assets, and/or using the global commons, such as fishing in international waters or polluting CO2 into the global atmosphere.
In contrast, when there is enough biocapacity to support the population’s Ecological Footprint in net terms, there is an ecological reserve.
If more bioproductive land and sea is required than is available, then it is likely that the rate of consumption is not sustainable.
These figures provide different messages on the Ecological Footprint.
In 2007, humanity’s worldwide Ecological Footprint was 18.0 billion global hectares. With a world population at 6.7 billion people, the average person’s Footprint was 2.7 global hectares. But there were only 11.9 billion gha of biocapacity available, or 1.8 gha per person. This indicates that we have already crossed the biocapacity of the earth and our consumption practice is unsustainable.
We can see Brazil has the highest level of biocapacity and followed, in decreasing order, by China, the United States of America, Russian Federation, India, Canada, Australia, Indonesia, Argentina, and Bolivia.
Interestingly, half the world’s biocapacity is found within the borders of just eight countries.
Figure 3 compares the global Ecological Footprint and biocapacity by land use type. The carbon Footprint is comparatively high compared to the biocapacity components other than carbon Footprint. A net deficit results when a region’s Footprint exceeds its biocapacity.
Either the ecosystem resource stocks will be depleted, or new resources must be imported from elsewhere.
The following six assumptions are fundamental for the Ecological accounting (Wackernagel et al., 2002) method.
• Most resources people consume and the wastes they generate can be tracked.
• Most of these resources and waste flows can be measured in terms of the biologically productive area necessary to maintain flows.
• Resources and waste flows that cannot be measured are excluded from the assessment, leading to a systematic underestimate of humanity’s true Ecological Footprint. By weighting each area in proportion to its bioproductivity, different types of areas can be converted into a common unit of global hectares, hectares with world average bioproductivity.
• A single global hectare represents a single unit, and all global hectares in any single year represent the same amount of biodiversity, they can be added up to obtain an aggregate indicator of Ecological Footprint or biocapacity.
• Human demand, expressed as the Ecological Footprint, can be directly compared to nature’s supply, biocapacity, when both are expressed in global hectares.
The accounting approaches are different with respect to their approach of collating key data, converting consumptions data into land areas, as well as their key focus areas.
Compound approach (Top-down):
The compound approach, also known as the top-down approach, collates data from international sources to calculate comparable national Footprints.
The data to be collated will be related to production, trade, agriculture yield, national consumption data, equivalence factors, yield factors, and other variables.
This approach includes the following steps for each country:
• Collation of production and international trade date from an official database
• Adjustment of data to account for consumption of goods and service (i.e., Consumption = Production + Imports-Exports)-which is economic input-output analysis.
• Biological productivity data is collated and used to convert consumption data into land and water areas, and
The Ecological Footprint aims to identify the impact of nations’ consumption rather than production, so imported goods have to be added and exported goods subtracted. Thus, the compound approach relies heavily on trade data to enable the calculation of domestic consumption.
The output of the compound approach presents a country’s Ecological Footprint in terms of its use of the six different areas types
• Arable land
• Pasture land
• Forest
• Fishing grounds
• Degraded or built land, and
• Energy land
Energy land is the dominant land use required to absorb CO2 emissions.
The key feature of the component approach is it first establishes the amount of activity undertaken by population and then converts this into energy and direct land use.
The numbers of hectare that results from this aggregation are then converted to global hectare using yield and equivalence factor.
The component approach is more data intensive than the compound approach, since national statistics are rarely in a manner that will easily identify material and energy flows for sub-national populations.
• The consumption of direct energy: includes the energy used in the home by commercial and public services, such as hotels, education and health services. This includes the consumption of gas, electricity, and other fuels (in some case renewable).
• The use of personal/passenger transport: includes all cases of personal transport: cars, buses, rail and air travel.
• The consumption of food and drink: in the home and eaten out, as well as the energy and resources used in production of food are included in the Ecological Footprint.
• The consumption of water: the Ecological Footprint of water consumption is based on the energy required for extracting, treating, and supplying water to consumers.
• The consumption of goods/the production of waste: enerally covers all goods that are not considered elsewhere in the Ecological Footprint. The environmental life cycle impacts of consumptions are considered in the Ecological Footprint.
Goods/material and waste are generally considered as two aspects of the same activity, which implies the use of resources and embodied energy. Thus, either goods or waste data are used to calculate the Footprint depending on data availability and accommodating buildings and infrastructure - built up (or degraded) land generally refers to all areas that are built on, contaminated or degraded to the degree that is rendered biologically unproductive. (waste) 121030506
See Defra report on Sustainable Consumption and production - Development of an Evidence Base Study of Ecological Footprint -2005.
http://randd.defra.gov.uk/default.aspx
Equivalent Factors represent the world’s average potential productivity of any given bioproductive area relative to the world’s average potential productivity of all bioproductive areas.
The equivalent factors are constants for all countries for a given year and are derived from the suitability index of Global Agro-Ecological zones (GAEZ) 2000 which is a spatial model of potential agricultural yields.
The global average productivity per hectare for a given year is assigned the equivalence factor of one. Therefore, the arable land and forests generally have equivalent factors of more than one as they are generally more bioproductive.
Yield Factors reflect the inherent productivity of land, which depends on the soil fertility and harvesting method, given the country’s prevailing technology and management practices. The yields of crops will vary from the world average yields.
Therefore, a yield factor of 1.5 simply means that the local yield is 50% higher than the world average.
Global Hectares are standardized units of measurement of the Ecological Footprint. Each global hectare represents an equal amount of biological productivity.
One global hectare is equal to one hectare with productivity equal to the average productivity of the 11.40 billion bioproductive hectares on Earth.
As discussed, the Ecological Footprint calculation accounts for different types of productions and land use areas that are captured by Equation as presented.
Calculate your environmental Footprint with the World Wide Fund’s Footprint Calculator.
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Basically, this illustrates how we consider the different types of consumption and use the ecological equation.
There are six types of land used for accounting:
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Click each type to learn more.
Cropland includes the land area used for growing crops for food, animal feed, fiber, and oils. It has the greatest average bioproductivity per hectare. The Food and Agriculture Organization of the United Nations (FAO) estimates that there are roughly 1.5 billion hectares of cropland worldwide as of 2003.
Grazing land corresponds to our consumption of meat, dairy products, hides, and wool that come from livestock in permanent pastures. Worldwide, there are approximately 3.5 billion hectares of natural and semi-natural grassland and pasture. The area of grazing land demanded by a livestock product is calculated by using the amount of pasture grass that is needed to meet the total feed requirements of that product, after subtracting the other sources of feed used.
Fishing grounds correspond to the area required to produce the fish and seafood products. This includes all marine and fish water, crustaceans (mainly aquatic group Crustacea, such as a crab, lobster, shrimp, or barnacle) and cephalopods (such as an octopus or squid) as well as fishmeal products and oils that are fed to animals and farmed fish.
Forest land includes all land required for timber product, whether in the form of sawn wood, wood-based panels or fish board as well as pulp, paper and paperboard. In order to calculate the Footprint, consumption of forest products is converted into the forest required to produce them.
Carbon land: The Ecological Footprint of fossil fuel consumption is calculated by estimating the biologically productive area required to assimilate the waste product of the human economy. The biologically productive area required to absorb the carbon dioxide, not sequestered by the oceans, is calculated using the carbon absorption potential of world average forest. It is noted that sequestration capacity changes with both the maturity and composition of forests and with possible shifts in bioproductivity due to higher atmospheric carbon dioxide levels.
Built-up land corresponds to land required for building the infrastructure for housing, transportation, and industrial production. Areas occupied by hydroelectric dams and reservoirs, used for the production of hydropower, are also counted with built up land.
IMG SOURCE: <http://upload.wikimedia.org/wikipedia/commons/d/d5/Carbon_cycle.jpg>
In contrast to the Ecological Footprint method, biocapacity’s accounting framework by the Global Footprint Network considers the previous land types except energy land.
Biologically productive areas support significant photosynthetic activity and biomass accumulation that can be used by humans.
Areas not included in the calculation: Nonproductive and marginal areas such as arid regions, open oceans, the cryosphere (portions of Earth's surface where water is in solid form, including sea ice and frozen ground), and other low-productive surfaces as well as areas producting biomass
The amount of biocapacity available per person globally is calculated by dividing the 11.2 billion global hectares of biologically productive area by the number of people on Earth.
As we know, if the Ecological Footprint is higher than biocapacity, the region seems to be unsustainable and demand should be supplemented by importing from other regions or countries.
For current global figures, visit the Global Footprint Network.