CHAPTER 3 ECOLOGICAL FOOTPRINT ANALYSIS This section of the literature review examines the ecological footprint as a method to measure, determine, and convey sustainability. Theoretical underpinnings, methodology, strengths and limitations, and examples of how ecological footprints have been applied are detailed. This chapter concludes with the rationale for choice of the ecological footprint as an appropriate tool to measure sustainability at institutions of higher education. Antecedents Ecological footprints rely heavily on the concept of carrying capacity—the number of a species that can be supported indefinitely in a given area without degrading the sustaining nature of that area (Rees 1996). The drive to measure the carrying capacity of the earth dates back several hundred years and includes a variety of approaches. In 1798, Reverend Thomas Malthus introduced his Essay on the Principles of Population as it Affects the Future Improvement of Society, in which he identified exponential population growth and predicted that this growth would outpace the earth’s agricultural production 1 . In 1902, Leopold Pfaundler estimated that the carrying capacity of the earth was roughly five people per hectare 2 (Wackernagel and Rees 1996 from Pfaundler 1902). Ghost acreage, a term used to describe insufficient biocapacity and 1 Was Malthus incorrect? Agricultural productivity has increased exponentially in the last 100 years due to technological advances. However, this has necessitated an exponential growth in the use of nonrenewable fossil fuels necessary to produce this agriculture, the depletion of aquifers, and the loss of soil fertility. Perhaps the verdict is still out on his prediction. 2 One hectare is equal to 2.47 acres.
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CHAPTER 3
ECOLOGICAL FOOTPRINT ANALYSIS This section of the literature review examines the ecological footprint as a
method to measure, determine, and convey sustainability. Theoretical underpinnings,
methodology, strengths and limitations, and examples of how ecological footprints have
been applied are detailed. This chapter concludes with the rationale for choice of the
ecological footprint as an appropriate tool to measure sustainability at institutions of
higher education.
Antecedents
Ecological footprints rely heavily on the concept of carrying capacity—the
number of a species that can be supported indefinitely in a given area without degrading
the sustaining nature of that area (Rees 1996). The drive to measure the carrying
capacity of the earth dates back several hundred years and includes a variety of
approaches. In 1798, Reverend Thomas Malthus introduced his Essay on the Principles
of Population as it Affects the Future Improvement of Society, in which he identified
exponential population growth and predicted that this growth would outpace the earth’s
agricultural production1. In 1902, Leopold Pfaundler estimated that the carrying capacity
of the earth was roughly five people per hectare2 (Wackernagel and Rees 1996 from
Pfaundler 1902). Ghost acreage, a term used to describe insufficient biocapacity and 1 Was Malthus incorrect? Agricultural productivity has increased exponentially in the last 100 years due to technological advances. However, this has necessitated an exponential growth in the use of nonrenewable fossil fuels necessary to produce this agriculture, the depletion of aquifers, and the loss of soil fertility. Perhaps the verdict is still out on his prediction. 2 One hectare is equal to 2.47 acres.
33
subsequent imported agricultural carrying capacity, was developed by Georg Borgstrom
(1973). In 1980, William Catton (1980) introduced Overshoot: The Ecological Basis of
Revolutionary Change, in which he detailed the potentially detrimental effects of
ecological overshoot—the failure to work within the long-term carrying capacity of the
planet. Several years later, Peter Vitousek et al. (1986) estimated that by 1980,
humanity had appropriated over 40 percent of the earth’s capacity to produce biomass,
suggesting that insufficient capacity was intact for the remainder of the species. The
‘environmental space’ concept, developed in 1992, attempts to quantify the Earth’s
ecosystem’s finite capacity to absorb environmental pressures without suffering
irreversible damage (European Environment Agency 2004). The ultimate precursor to
the Ecological Footprint was the ‘regional capsule’ first introduced by William Rees in the
1970s to initiate students to the concept of carrying capacity (Wackernagel and Rees
1996).
Theoretical Basis for Ecological Footprints
Ecological Footprint Analysis (EFA) was initially conceptualized by William Rees
and further developed by doctoral student, Mathis Wackernagel, in the mid 1990s. It is
an approach that relies on the determination of biophysical limits of planetary natural
ecosystems, which in turn inform the scope and scale of human activities (Rees 1992).
Thermodynamic laws and the ability to measure biocapacity provide the ecological
foundations that support the concept of footprints.
The first law of thermodynamics establishes that energy is neither created nor
destroyed, indicating a closed system. The second law, or the ‘entropy law’, states that
entropy, or disorder, increases, implying that energy decreases or degrades in a closed
system (Chambers et al. 2000). The end state is characterized by lower quality energy,
diminished in its ability to work—a degraded system (Wackernagel and Rees 1996).
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Highly organized systems, such as the human body or the economy, also experience
entropic decay. They require constant input and conversion of energy from host
environments, and thus develop “at the expense of increasing disorder at higher levels in
the systems hierarchy” (Wackernagel and Rees 1996:43 from Schneider and Kay 1992).
Ultimately, if the demands of human economy exceed the restorative capability of the
ecosphere, its host system, significant entropy occurs. Evidence of this phenomenon is
global climate change, pollution, loss of biodiversity, and the liquidation of natural capital.
Wackernagel and Rees (1996:43) suggest the human economy is a “nonequilibrium,
dissipative structure—an open, growing subsystem of a materially closed, non-growing
ecosphere.”
The law of mass conservation, which posits that mass is neither created nor
destroyed, supports the earth and human activities essentially as metabolisms that can
be measured with regard to both input matter and waste output (Chambers et al. 2000).
Ecological footprints draw on this ability to measure inputs and outputs, or throughput, to
the human economy, to determine whether we are living within the capacity of our
system.
Ecological Footprint Defined
Specifically the ecological footprint “quantifies for any given population the
mutually exclusive, biotically productive area that must be in continuous use to provide
its resource supplies and to assimilate its wastes” (Wackernagel and Yount 1998: 514).
Conceptually, this is akin to placing a dome over a city or nation and quantifying the
necessary geographic area the dome would require for inhabitants to carry on present
activities given the prevailing technologies. Ecological footprints represent an inverse
relation of the carrying capacity concept: it provides us with an estimate of how much
land is needed to support our activities rather than how many humans can live on a
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given quantity of land (Rees 1996). Ecological footprints have also been termed
‘appropriated carrying capacity’ to reflect the way in which human impacts are
aggregated into mutually exclusive ecological spaces that supply the desired services
and products of nature (Wackernagel and Yount 1998). EFA considers biologically
productive land and sea areas to be mutually exclusive, facilitating human consumption
and assimilation requirements to be compared to the available bioproductive capacity on
earth.
Biologically productive land provides the majority of the earth’s biomass and is
estimated to total 11.4 billion hectares (28 billion acres), or one quarter of the earth’s
surface. The remaining surface area consists of lower productivity categories including
deserts, polar ice caps, and deep oceans (Loh 2002). Given current population figures of
just over 6 billion, the available global per capita footprint capacity, consisting of
biologically productive land and sea, divided equally among the earth’s inhabitants, is
estimated to be 1.9 hectares (4.7 acres). This figure is also known as the fair earthshare
(Chambers et al. 2000). According to the Ecological Footprints of Nations 2002 report,
humanity is exceeding the Earth’s biological capacity by more than 20 percent, with an
average per capita footprint of 2.3 ha (Wackernagel et al. 2002).
Biodiversity. The footprint capacity above does not specifically designate capacity for
the other 12 million species that inhabit the earth. As noted in Chapter 1, every major
species is in decline due to loss of habitat, pollution, overharvesting, and the introduction
of foreign plants and animals (Starke 2003; Chambers et al. 2000). Ecologists vary on
how much area should be set aside for protecting biodiversity, but estimates range from
25 to 70 percent of bioproductive land on earth (Chambers et al. 2000 from Odum 1970
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and Noss and Cooperrider 1994)3. Today, only 3.5 percent of global lands are protected.
The World Commission on Environment and Development recommends 12 percent of
the biological capacity be set aside for protecting biodiversity. Ecological footprint
analysis uses this 12 percent target because it is currently most palatable. With 12
percent of bioproductive land and seas assigned to protecting biodiversity, the fair
earthshare drops to 1.7 hectares (4.5 acres) per person (Chambers et al. 2000).
Ecological deficits. When a country’s footprint exceeds the biotically productive area of
its borders, the country runs an ecological deficit. Loh and Wackernagel (2004) suggest
that only 40 percent of countries in the world fail to exhibit an ecological deficit. Global
trade allows deficits to be externalized to the commons, currently evidenced by vast
increases in carbon dioxide and subsequent global warming (Templet 2000). Trade also
facilitates the import and export of biocapacity. Countries with ecological comparative
advantage, endowed with higher resource productivity or greater stores of natural
resources, export this capacity within trade products to other nations (Wackernagel and
Yount 1998).
Global inequity. Footprint analyses of nations reveal that a disproportionate amount of
productive area is required to support the lifestyles of those in industrialized countries
(See Figure 3.1). Globally, the U.S. appropriates the largest ecological footprint at 24
acres per capita compared to 3.8 acres per capita in China (Loh 2002). It is estimated
that it would require approximately three additional planet earths to bring our world of six
billion humans up to the average North American material standard (Rees 2001). This
disparity in consumption and waste production, where “the wealthiest 20 percent of the
world’s population in the North are consuming approximately four-fifths of the world’s
3 Odum proposed 40 percent for biodiversity. Noss and Cooperrider suggested between 25 and 75 percent.
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Figure 3.1 Ecological Footprint by Region 1999
0
5
10
15
20
25
North A
merica
Western
Europe
Centra
l and Eas
tern Euro
pe
Latin A
merica a
nd the Cari
bbean
Middle Eas
t and C
entral A
sia
Asia-P
acific
Africa
Regions
Glo
bal a
cres
per
per
son
Per Capita Footprints
(Adapted from Loh 2002)
natural resources” (DeKruiijf and Van Vuuren 1998: 5) has prompted calls for a reduction
in the material needs of the North and even a reversal of funds from North to South to
pay for the ecological debt (KAIROS, 2002). This widening gap in consumption and
wealth is indicative of structural unsustainability and represents a challenge for colleges
and universities of industrialized nations that seek to lead the charge in sustainable
development.
Methodology
Footprints are calculated with either the compound or component-based method,
or a hybrid combination of these methods. The choice of method is determined primarily
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by scale (size of the entity measured), and the format of available data. Both methods
produce comparable footprints, which reinforce their validity (Chambers et al. 2000).
Compound method
The compound method is applied primarily at the nation state level and utilizes
national production, as well as import and export data to determine consumption for over
50 biotic resources (Chambers et al. 2000). There are six main stages for calculating a
per capita footprint using this method. First, production of these resources such as
wood, grains, and meat, is calculated and adjusted by adding imports and subtracting
Second, these consumptive categories are converted to quantities of five specific
land and sea types including, cropland, forest, pasture, built land, and sea according to
which land types are required for production or assimilation of these items (Table 3.1)
(Wackernagel and Rees 1996). A sixth land type, energy land, is added to account for
the direct use of energy by the nation as well as the embodied4 energy involved in the
production of consumption items. In the equation above, corn requires the appropriated
capacity of both energy and cropland categories. Several approaches have been offered
for calculating energy land including the sequestration of carbon dioxide, the growing of
alternate fuel crops, or the replacement of biomass to produce fuels (Wackernagel and
Rees 1996). The most utilized method is carbon sequestration in which the assimilative
capacity of forests and oceans to capture and store carbon dioxide is calculated and
assigned the necessary forest and sea area, termed energy land (Wackernagel et al.
4 Embodied energy refers to the energy used for the entire life cycle of manufacturing, transport, use and disposal of a given commodity (Chambers et al. 2000)
39
2003). Carbon dioxide for human activities is quantified and then translated into
corresponding energy land.
Table 3.1 Productive Land Areas used in Ecological Footprint Analysis Productive land type Land use Percentage of
total land on earth
Per capita area available on
earth
Cropland (Arable)
Land under temporary or permanent cultivation, staple
crops of grains, tubers, pulses,
Highest productivity land
10 .25 ha
Pasture Grazing land for livestock, to produce dairy products and
meat
23 .6 ha
Forest and woodland Tree plantations or natural forests that can yield timber
products.
33 .6 ha5
Ocean (Productive sea space)
8 percent of this area, located on continental coasts,
provides 90-95 percent of sea’s ecological production
Represents 36.3
billion hectares on earth
.5ha productive
6 ha total
Built-up land Land for human settlements and roads
2
.03 ha
Energy land Land required for sequestration of CO2
No land used exclusively for this
purpose
----
Other land6 Wetlands, ice, rock, desert, tundra, lakes and rivers.
32 Not used in
Footprint (Adapted from Wackernagel and Yount 1998; Chambers et al. 2000)
The conversion to land area results from dividing consumption quantities for
each category by their corresponding world average biotic productivity7, or yield, to
determine the ecological footprint for each category. At the national level, world average
productivity is used for each land type in order to simplify calculations, avoid the tracing
5 1.7 billion hectares of the total 5.1 billion hectares of forests and woodlands are lightly wooded, some with as little as 10 percent tree cover. When this portion is subtracted from the total forest and woodland, there is a remainder of 3.4 billion hectares, which when divided by the earth’s population allows for .6 hectares per capita (Chambers et al. 2000). 6 There is debate on classification of this land as ‘unproductive’ (not included in the capacity of footprints). Oceans were recently assigned an absorptive capacity of 31 percent of carbon emissions (Wackernagel et al. 2003). This highlights the difficulty in assigning a quantitative value to ecological assets. 7 World average biotic productivity figures sourced from FAO estimates of world average yield.
40
of sources of trade products and waste sinks, and to create a common base yield for
inter-country comparisons.8
Rees (2001) represents this by:
ai = ci/yi
Where ai is the footprint of item ‘i’ in hectares ci is the total consumption of item ‘i’ in kilograms yi is the yield of item ‘i’ in kilograms per hectare For corn:
acorn = ccorn/ycorn = kgcorn/(kgcorn*hacorn-1)
Third, footprints for individual consumption categories are aggregated to reach
the total ecological footprint of the entity or population (Fp )
Fp = ∑=1i
nai
Where n is the number of consumption categories in the footprint
Fourth, the total footprint is divided by the size of the population (N) to achieve a
per capita footprint (Fc).
Fc =Fp /N
Fifth, to facilitate comparison of footprints between nations, footprints are
multiplied by equivalence factors to express the final footprint in global hectares or
acres—those with average biomass productivity. This allows comparison between
regions that have varying qualities and mixes of pasture, cropland and forest. The use of
equivalence factors highlights a nation’s appropriation of different land types with varying
productivities. Each land type is assigned an equivalence factor that reflects its relative
capacity to produce biomass. A factor of 2.2 for cropland signifies that it is 2.2 times
8 When these footprints are subsequently compared to the particular nation’s biocapacity, the actual nation’s productivity for each land type is used to calculate available biocapacity.
41
more productive than world average bioproductive land. Pasture land with a .5
equivalence factor is half as productive as the world average (Wackernagel et al. 2003).
Finally, the available biocapacity of the nation is compared with the ecological
footprint to determine either an ecological deficit, the exceeding of biological capacity, or
a surplus, where the footprint does not appropriate all of the available capacity. The
1993 footprint for Italy (Table 3.2) shows a 4.2 hectare per capita footprint, which
Table 3.2. Calculation of the Italian’s Average Ecological Footprint (1993 Data) DEMAND SUPPLY
FOOTPRINT (per capita) EXISTING BIO-CAPACITY WITHIN COUNTRY (per capita)
Category total equivalence equivalent Category yield national yield adjusted
factor total factor area equiv. area
[ha/cap] [ - ] [ha/cap] [ha/cap] [ha/cap]
fossil energy 1.4 1.1 1.6 CO2 absorption land 0.00 0.00
built-up area 0.1 2.8 0.2 built-up area 1.49 0.04 0.17
arable land 0.3 2.8 0.9 arable land 1.49 0.21 0.87
pasture 1.8 0.5 1.0 pasture 6.50 0.08 0.26
forest 0.3 1.1 0.3 forest 0.80 0.12 0.11
sea 1.0 0.2 0.2 sea 1.00 0.32 0.07
TOTAL existing 0.8 1.5
TOTAL used 4.9 4.2 TOTAL available
(minus 12% for biodiversity) 1.3
(Adapted from ICLEI 1998)9
compared to available capacity, represents a 2.9 (ha/cap) ecological deficit
(Wackernagel et al 1999). Fossil energy land is the largest contributor, 38 percent, to the
overall Italian ecological footprint followed by pasture land.10 Energy is typically one of
the largest components of all ecological footprints and has been steadily increasing for
the past 100 years (Figure 3.2).
9 Equivalence factors have been modified since this 1998 report and thus are different than those found elsewhere in this thesis. 10 Fossil energy land becomes a larger contributor than pasture land after equivalence factors are applied.
42
Figure 3.2. Change in Composition of Global Ecological Footprint 1961-1999
The compound method relies on material flows at the national level and
established trade data. This makes this method more robust for comparisons between
nations. However, these data are rarely available for cities or organizations. As a result,
the component-based method was developed concurrently to calculate footprints on a
local scale.
Component-based method
This method was developed by Best Foot Forward and C.A.G. Consultants to
determine footprints for domestic entities (Simmons et al. 2000). Consumption use from
individuals or organizations is aggregated in a bottom-up manner to the required level
rather than disaggregated from national data. The land use categories used for compound
analysis are also used for component-based analysis. This approach emphasizes the
(Adapted from Loh 2000)
0
2
4
6
8
10
12
14
16
1960 1965 1970 1975 1980 1985 1990 1995 2000
Bill
ion
glob
al h
ecta
res Built-up land
Energy land
Fishing Grounds
Forest
Grazing land
Cropland
43
activities of an organization rather than cumulative resource use and relies on sources of
information that are more accessible for individuals and organizations. For example, fuel
use by cars is sourced from the measurement of miles driven rather than the amount of
fuel purchased. This method has the benefit of greater local transparency, which facilitates
comparisons between impacts of different activities and experimentation with possible
sustainability scenarios. For example, when an organization is designing a new building it
can use the component-based footprint to evaluate energy and material options, ultimately
making choices that result in smaller footprints. The categories that organizations typically
measure with the component-based approach are provided in Table 3.3.
Table 3.3 Component Categories Included in Ecological Footprints of Organizations
Component categories
Electricity (GWh) Gas - Heat Travel (km/yr) (cars, bus, train, air) Food Water Built land Landfilled waste (tons) Recycled waste (tons) Wood products
(Adapted from Simmons et al. 2000)
Determining Sustainability
Footprint analyses produce a single number, the appropriated land area required
to support an entity’s activities. Translating this number into an analysis and conclusion
of ecological sustainability or unsustainability is not supported by a standardized
method. The definitional discussion regarding sustainability is repeated in attempts to
determine specific quantifiable levels of sustainability. A framework that has received
some acceptance, which will be used for assessing the ecological footprint of UCCS, is a
hierarchy of three approaches to sustainability ranging from most to least stringent and
44
represented by ideal, strong, and weak sustainability (Wackernagel and Rees 1996;
Venetoulis 2001). Venetoulis (2001) depicted this framework in his evaluation of the
sustainability of Redlands University to conclude that the school met weak sustainability
conditions.
Ideal sustainability conditions are reached “when all consumption and absorption
of ensuing waste occurs in the place where consumption directly occurs” (Venetoulis
2001:187). This is a stringent standard in which the resource endowments and waste
assimilation capacity of a particular locality designate the ecological capacity. In this
analysis, a university’s footprint would be limited mainly to the quantity of available
biocapacity found within its borders, adjusted by yield and equivalence factors for the
types of land present.
Strong sustainability is based on a comparison between individual ecological
impacts and global carrying capacity. For the university to meet strong sustainability, its
members would have footprints equal to or less than the global quantity of bioproductive
land available per capita, or the fair earthshare of 4.7 acres (Chambers et al. 2000). In
this approach natural resources are considered rarely substitutable and it is emphasized
that both natural capital and human capital levels must be separately maintained (Daly
and Cobb 1994; Wackernagel and Rees 1996).
Weak sustainability is measured by a comparison between an individual’s
ecological impact and the available biocapacity within this individual’s nation (Venetoulis
2001). For example, a member of the UCCS campus would have to exhibit a footprint of
less than 13.2 acres, the available per capita biocapacity existing within the U.S, to meet
weak sustainability criteria. This relatively large amount of U.S. biocapacity, in
comparison to other nations, facilitates overconsumption by Americans, while allowing a
classification of weak sustainability. Weak sustainability conditions tend to favor
countries with high biocapacity within their borders, making this analysis unattractive to
45
island nations like Hong Kong, which rely on significant imports of biological capacity.
The weak approach to sustainability suggests that natural resources are ultimately
substitutable and that as long as the total quantity of natural and human capital
combined is maintained, weak sustainability conditions are met. Critics of the weak
sustainability approach maintain that global trade incurs ecological damage far removed
from the end consumption point and thus negates an analysis that is limited to a nation’s
ecological limits (Wackernagel and Rees 1996).
Strengths of Ecological Footprint Analysis
Ecological footprints have gained acceptance from many nations, municipalities,
universities, organizations and individuals for the following reasons: 1) Footprints are
easy to comprehend and communicate. They “provide an intuitive framework for
understanding the ecological bottom line of sustainability” (Wackernagel and Rees 1996:
57). Footprints convey that humans are dependent on ecological goods and services
that must be managed in ways that ensure their continued support of our survival. 2)
Footprints illuminate areas of highest impact to be addressed in the short term, which in
turn gives focus to environmental solutions. The depiction of the growing reliance and
subsequent impacts of fossil fuel dependence feeds the discussion on the development
of renewable fuels. 3) Footprints reveal gross global inequities in resource use and
distribution. This analysis forces the recognition of the connections between wealth
accumulation in industrialized nations and exacerbation of poverty in less developed
countries (Venetoulis et al. 2004). Results from footprints strongly suggest that
addressing this sustainability gap is a major precondition to worldwide sustainability. 4)
Footprints allow comparison of activities based on ecological impacts. For example, fish
farms are considered to be a positive solution for global fish declines. However, William
Rees (2003a) and students found the ecological footprint of fish farms to be significantly
46
larger than open water catches due to the intensity of raising food for the fish farms. 5)
Finally, footprints conceptually clarify the interconnectedness and interdependent
relationships of world entities. There is no ‘away’ when we throw away waste, sadly
demonstrated by the mounds of discarded toxic computers that children comb for parts
in rural China (Gray 2004). Currently the advancement of industrialized nations
significantly depends on importing biological capacity for our success and subsequently
exporting waste that cannot be assimilated within our borders.
Limitations of Ecological Footprint Analysis
Ecological Footprint Analysis has received numerous critiques, some with
suggestions for significant modification of the methodology. Criticisms have focused on
data variability (Bicknell et al. 1998), choice of weighting and subsequent conversion
figures (Van den Bergh and Verbruggen 1999), exclusion of nonrenewable resources and
pollutants, and finally, sequestration schemes and spatial delineation (Ayres 2000; Lenzen
and Murray 2001; Van den Bergh and Verbruggen 1999; Van Kooten and Bulte 2000).
Much of the criticism highlights the tool’s nature as an underestimate, failing to fully
account for all impacts. A discussion of the most common critiques follows.
Due to great geographic variability, ecological footprints do not adequately account
for freshwater footprints. The footprint does not have an efficient way to distinguish
between energy intensive water pumping schemes for arid zones and those for wetter
climates. For example, the impact of drawing down aquifers, such as the Ogallala, is not
measured in the footprints (Wackernagel and Yount 1998). EFA does not distinguish
between sustainable and unsustainable land uses and thus, all cropland use is considered
equal. Soil degradation from pesticide and fertilizer use is unaccounted for in the footprints
(Van den Bergh and Verbruggen 1999). Pollutants other than carbon dioxide, such as
NO2 or toxic chemicals are not included in footprints. Toxic chemicals are considered
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unsustainable and slated for elimination (Wackernagel and Rees 1996). Land categories
are assigned a single use by ecological footprints even though some likely serve multiple
purposes (Van den Bergh and Verbruggen 1999). This tends to inflate the results of
ecological footprints. Ecological footprints don’t differentiate between domestically
produced consumption and imports and therefore do not have the specificity to indicate
where environmental impacts occur. A country may show an ecological surplus, but import
from a country that conducts unsustainable practices. This decreases the ecological
footprint’s ability to be used as a regional planning tool (Lenzen and Murray 2001).
Footprints represent a snapshot of ecological impact and cannot incorporate future
changes in technology. Wackernagel and Rees (1996) acknowledge that EFA represents
a static measurement, a baseline with which to compare repeated footprints. Finally,
ecological footprints, by themselves, are unable to measure quality of life and equity
requisites for sustainability and must be used in conjunction with other social indicators.
Methodological limitations. While conducting the ecological footprint for UCCS, I
discovered several methodological challenges. Selecting appropriate conversion methods
proved to be one of the most difficult obstacles. EFA lacks a unified institutional approach
to measurement resulting in footprints that vary dramatically due to chosen multipliers.
Tables 3.4 and 3.5 feature electricity and natural gas footprints from several universities
and demonstrate how different methods, all considered ecological footprints, can result in
vastly different results with identical consumption input. Some of the variation in these
footprints is due to different energy mixes (specific to electricity), to the decrease in carbon
sequestration rates (Venetoulis 2004) and to rounding erors. For example, the
sequestration rate for carbon has changed since the methodology’s inception from 1.8
metric tons per hectare, to .95 metric tons per hectare, indicating that energy land is now
thought to be able to assimilate only half of what was originally calculated (Chambers
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Table 3.4. Comparison of University Natural Gas Footprints using Different Methods with UCCS 2003 Natural Gas Use of 587,564 CCF
Household Calculator: Includes several multipliers not in other methods. Structural Consumption Multiplier = 1.1. This multiplier is applied to all the total fossil energy footprint components of each consumption category and represents the embodied and direct energy consumed by the government to purchase public goods and services. Fossil Energy Correction Factor for U.S. for Buildings (Housing) = .98. The Correction Factors calibrate this household footprint spreadsheet with the national footprint accounts for the U.S., so that the "average" footprints are equal using both assessment methods. Sequestration rate is .95 t C/ha. Difference between Input data footprint and hand calculated footprint is assumed to be due to rounding. University of Newcastle: Sequestration rate is 100Gj/ha. University of Redlands: Conversion figure of .00157 is given on spreadsheets for calculating footprint of natural gas for a given number of therms. Colorado College: Sequestration rate is 1.8 metric tons C/ha. Assume 14.33 grams Carbon per cubic foot of natural gas.
and Lewis 2001; Redefining Progress 2004). Additionally, the Household Ecological
Footprint Calculator v.3.2 applies several multipliers such as structural consumption and
U.S. Correction Factors that other methods do not include. The relative infancy of EFA
corresponds with few experts in the field to solve methodological quandaries as well as
changing multipliers. Transparency in methodology and calculations is not always
forthcoming11. Redefining Progress and the Global Footprints Network are two non-profit
11 As part of a global ecological footprint listserve, I have been witness to a steady dialogue regarding lack of transparency and some potential errors in some of the methodology in footprints. Nonprofit organizations and businesses that use the footprint methodology to consult naturally wish to keep their methods a business secret. This has angered some in the science community who wish to achieve greater standardization and accuracy.
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Table 3.5. Comparison of University Electricity Footprints with Different Methods given UCCS 2003 Electricity Consumption of 15,564,208 kWh
Method Calculations Footprint (Acres)
University of Vermont – Erika Swahn Sharing Nature’s Interest
Range of Footprints = 1383.97 – 10,406.7 = a difference of 9022 acres depending on method. If we take out the high and low estimates, the range is 5,597 – 8,354.8, a difference of 2758 acres. Assumptions: Colorado Springs composition for Electricity – 52% coal, 35% Natural Gas, 13% Hydro. This composition is fully accounted for only in the University of Redlands method. Electricity use of 15,564,208 kWh (UCCS Consumption 2003) is used for all examples. University of Redlands– Sharing Nature’s Interest - Sequestration rate of 1.8 tC/ha-yr. Colorado College – Assumptions: 100% electricity supplied by coal. Power plant operates at 31.4% efficiency. Coal has heat content of 20kJ per gram. Coal is 85% carbon by mass. Sequestration rate 1.8 tC/ha. Household Calculator – Sequestration rate of .95 t C/ha-yr. Calculator does not allow for separation of coal and natural gas. 87% entered as fossil fuel, 13% entered as Hydroelectric. Includes several multipliers not in other methods. Structural Consumption Multiplier = 1.1. This multiplier is applied to all of the total Fossil Energy footprint components of each consumption category and represents the embodied and direct energy consumed by the government to purchase public goods and services. Fossil Energy Correction Factor for U.S. for Buildings (Housing) = .98. The Correction Factors calibrate this household footprint spreadsheet with the national footprint accounts for the U.S., so that the "average" footprints are equal using both assessment methods. University of Newcastle – Sequestration rate of 100Gj/ha. 100 percent coal fired electricity generation.
organizations working to further the footprint methodology12. There are also a handful of private consulting firms, like Best Foot Forward in England, who have trademarked
12 Attempts to clarify methodology issues with Global Footprint Network were unsuccessful due to a current staffing shortage.
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footprint methodologies and are thus unavailable to students. Redefining Progress
recently received a grant to upgrade EF methodology and it is hoped that this will
facilitate the ability of more practitioners to use EF analysis (Venetoulis 2004).
Ecological Footprint Modifications
Several ecological footprint practitioners have modified the methodology in order
to address some of the critiques above. Two modifications, economic input-output
analysis and a land disturbance based approach, are included below.
Economic input-output data have been introduced to some ecological footprint
analyses in order to provide a more robust measurement of environmental impacts along
the entire life cycle of products. Traditional footprints typically measure the impacts of
first and second order producers and suppliers. Utilizing input-output data captures the
impacts of multiple layers of production and supply.13 First developed by Wassily Leontif
in the 1930s, input-output analysis details the connections between economic sectors
and can illuminate the link between demand for particular products and the creation of
undesirable by-products such as pollution (Bicknel et al. 1998). The first application of
this methodology was by Lichty and Jesswein (1978) to determine the financial impact of
the University of Minnesota on the city of Duluth. The resulting analysis detailed the
direct and indirect inter-industry, income and employment impacts, as well as student
expenditures. In 1998 Bicknel et al. utilized input-output methodology to determine the
ecological footprint of New Zealand. Recently, Wood and Lenzen (2003) applied a hybrid
ecological footprint approach that identified the structural paths of products and services
and was combined with input-output analysis to compare the impacts between two
research institutions in Sydney. They concluded that unmodified ecological footprints fail
13 The life cycle of a product may include numerous production and supplier levels, including retail stores, shipping facilities, distribution centers, processing and manufacturing plants, mining operations, etc.
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to measure the upstream effects of suppliers and producers and thus underestimate the
true impact of the entity measured. The result is a footprint that underestimates the
appropriation of land bioproductivity (Wood and Lenzen 2003).
The second modification is a regional, land disturbance-based approach that was
introduced to address the failings of linking sustainability with land productivity (Lenzen
and Murray 2001; Wood and Lenzen 2003). Ecological footprints use appropriated
world-average productivity to differentiate and weight land use. Lenzen and Murray
(2001) suggest that a more appropriate measure for determining sustainability is to base
footprints on local measures of how land cover is being disrupted. Their analysis
provides a weighted system from 1, consumed, to 0, slightly disturbed, in a six-category
delineation of alteration of the land from its original state. While this still falls short of
concluding whether this land is being used sustainability, it is more representative of
local conditions and highlights precursors, such as soil erosion, to unsustainability
(Wood and Lenzen 2003).
Wood and Lenzen (2003) conducted an ecological footprint of a research
institute in Sydney using four different methods. Their method, using the structural path,
input-output, disturbance-based approach led to footprints 20 percent larger than
traditional bioproductivity-based footprints. Additionally, appropriated land accounted for
a much larger portion of the footprint, 47 percent, than the bioproductivity-based
footprint, which assigned 5 percent to appropriated land.
The modifications described above are in their infancy and have not been
instituted in many footprints. The footprint for UCCS does not incorporate either of the
above modifications due to time considerations, focus of this project, availability of
purchase data, and the lack of resources to provide guidance. Incorporation of these
modifications may be used to improve future footprints of the university.
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Applications of Ecological Footprint Analysis National. Ecological footprints have been completed for more than 140 nations by a
partnership between WWF (formerly the World Wildlife Fund), the United Nations
Environment Program (UNEP) and the Global Footprint Network. Results, published in
the Living Planet Report 2004 for the year 2001, detail per capita footprints by nation
and highlight global trends in biodiversity (Figure 3.3). This report links growing global
footprints, 1.6 percent per year since 1961, with a correlated 40 per cent decline in the
Figure 3.3. Sample of 2001 Ecological Footprints from 2004 Living Planet Report
(Adapted from Loh and Wackernagel 2004)
Living Planet Index, which measures trends in populations of terrestrial, freshwater and
marine species (Loh and Wackernagel 2004). Global overshoot, originally estimated to
have occurred in the early 1970s, continues to grow and is now estimated to be nearly
20 percent (Figure 3.4) (Loh and Wackernagel 2004; Venetoulis et al. 2004). Redefining
Ecological Footprint per Person
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Progress also published an ecological footprint assessment of the world in its 2004
Ecological Footprints of Nations (Venetoulis et al. 2004)14. Significant findings for this
Figure 3.4. Humanity’s Total Footprint 1961-2000
(Adapted from Venetoulis et al. 2004)
report include: 1) The United States moved into the first position for highest ecological
footprint in the world, 2) Between 1999 and 2000, the total Ecological Footprint for
humanity increased by 147 million global hectares to a total 13.2 billion global hectares,
and 3) Continuing its twenty year trend, global per capita ecological footprints declined
(Venetoulis et al. 2004).
Regional/municipal. The first application of footprint analysis to a city was Santiago,
Chile, in 1996 conducted by the International Council on Local Environmental Initiatives’
(ICLEI) Sustainable Santiago project with Mathis Wackernagel. The compound method
was used and disaggregated down to the regional level, using local data where
14 The Living Planet Report was formerly co-produced by Redefining Progress. The Global Footprint Network, directed by Mathis Wackernagel, now performs that role. Footprint results for the two organizations are not identical. For example, the Living Planet Report for 2004 assigns the seventh largest footprint to Estonia. The National Footprints 2004 places Estonia as the 12th largest. This emphasizes the need for greater transparency in the methodology.
0
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1961 1965 1969 1973 1977 1981 1985 1989 1993 1997
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54
available. The resulting footprint was 2.6 hectares per capita, slightly higher than the
footprint for Chile (2.4 ha/capita) as well as the global average footprint (2.0 ha/capita)
(Wackernagel 1998). This footprint also revealed the disparity of per capita footprints
within the city: the wealthiest 10 percent have footprints larger than the average
American, the poorest 20 percent exhibit footprints smaller than the average
Bangladeshi (Chambers et al. 2000).
Numerous municipalities worldwide are now using ecological footprint analysis to
measure and guide sustainability initiatives. Municipal footprints efforts have been most
prevalent in European nations: 8 municipalities in the Netherlands; 10 in Finland;
Navarra, Spain; Turin Province, Italy; Stavanger, Norway; Isle of Wight, Oxfordshire and
Guernsey, UK, and many others (Lewan and Simmons 2001). In 2004, ecological
footprints were calculated for 9 counties of the San Francisco Bay Area. Results
indicated that while the region’s per capita footprint of 20.9 is less than the U.S. average,
it is far above the level of sustainability (Redefining Progress 2004).
Santa Monica, California, is one municipality in the U.S. that has completed a
longitudinal analysis conducting ecological footprints for 1990 and 2000. Reduction in
natural gas and diesel use, the switch to more geothermal energy, and increased
recycling account for the reduction in Santa Monica’s footprint in the ten-year span
(Figure 3.5) (Hancock 2002). Santa Monica’s footprint decreased by 167 square miles,
to 20.9 acres per capita, 4 acres less than the U.S. average (Redefining Progress 2004).
While this footprint is still well above the 4.7-acre fair earthshare, the progress is
admirable. Santa Monica’s commitment to sustainability is well evidenced, “The long-
term impacts of policy choices will be considered to ensure a sustainable legacy” (City of
Santa Monica 1994 in Venetoulis et al. 2004:15). This public statement has been
supported by solid actions, including solar-powered electric vehicle charging stations,
city employee trip-reduction programs, and increased green space. Santa Monica’s
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footprint demonstrates both the hope that sustainability measures can reduce our
ecological footprints and the vast uphill challenge industrialized entities face in order to
achieve sustainability.
Figure 3.5. Comparison of Santa Monica’s ecological footprint 1999-2000
(Redefining Progress 2004) Institutional Footprints. Businesses and organizations are increasingly joining the
sustainability discussion and seeking tools to guide resource efficiency. “Eighty-nine
percent of Fortune 1000 companies think sustainability will be more important in the next
5 years” (Lovins 2004). Institutional analyses include Los Alamos National Laboratory,
New Mexico (Maltin and Starke 2002), Sydney Water Company, Australia, (Lenzen et al.
2003), Anglian Water Services, UK, (Chambers et al. 2000), the National Health Service
(NHS) of England and Wales (Stockholm Environment Institute [SEI] and Best Foot
Forward [BFF] 2003) and many others. Organizations conduct primarily component-
56
based footprint analyses, utilizing local data when available, to create baseline
measurements, develop quantifiable scenarios, and to justify future policies.
The footprint conducted by the NHS of England and Wales in 2003 aimed to
determine areas of high consumption or waste that could be successfully approached by
sustainability strategies:
We recognise that the NHS, as a large organisation, will have a powerful role in helping to deliver a more sustainable future … Quantifying the environmental impact (‘ecological footprint’) of the NHS allows us to see where improvements could be made, in terms of promoting more sustainable patterns of consumption and reducing the quantity of waste that is generated, whilst still improving the social and economic circumstances of the country’s population…
Sir Nigel Crisp, Chief Executive of the Department of Health and NHS. (SEI and BFF 2003:1) The footprint highlighted significant impact in the categories of waste, energy and
transportation. NHS used this information to test scenarios of solar water heating, waste
minimization and recycling, and alternative transportation schemes to reduce its footprint
(SEI and BFF 2003).
University footprints. Ecological footprints are being conducted at a growing number of
universities. Published footprints consistently highlight that universities in industrialized
nations require significant amounts of imported biocapacity, caused predominantly by
energy consumption.
The University of Redlands in southern California conducted an audit of its
energy (electricity, natural gas, and gasoline), solid waste, and water to determine a
footprint of 5,700 acres, or 40 times the area of the campus. The composition was
typical of universities in developed nations that rely heavily on energy consumption: 32.5