The ecological footprint is a measure of human demand
on the Earth's ecosystems. It is a standardized measure of demand for natural
capital that may be contrasted with the planet's ecological
capacity to regenerate. It represents the amount of biologically productive
land and sea area necessary to supply the resources a human population
consumes, and to assimilate associated waste. Using this assessment, it is
possible to estimate how much of the Earth (or how many
planet Earths) it would take to support humanity if everybody followed a given
lifestyle. For 2007, humanity's total ecological footprint was estimated at 1.5
planet Earths; that is, humanity uses ecological services 1.5 times as quickly as
Earth can renew them. Every year, this number is recalculated to incorporate
the three-year lag due to the time it takes for the UN to collect and publish
statistics and relevant research.
Although the term ecological footprint is widely used
and well known, it goes beyond the metaphor. It represents an accounting system
for biocapacity
that tracks how much biocapacity there is, and how much biocapacity people use.
Calculation methods have converged thanks to standards released in 2006 and
updated in 2009.
Overview
The first academic publication about the ecological
footprint was by William Rees in 1992. The ecological
footprint concept and calculation method was developed as the PhD dissertation
of Mathis Wackernagel, under Rees' supervision at
the University of British Columbia in
Vancouver, Canada, from 1990–1994. Originally, Wackernagel and Rees called the
concept "appropriated carrying capacity".To make the idea more
accessible, Rees came up with the term "ecological footprint",
inspired by a computer technician who praised his new computer's "small
footprint on the desk". In early 1996, Wackernagel and Rees published the
book Our Ecological Footprint: Reducing Human Impact on the Earth with
illustrations by Phil Testemale.
Ecological footprint analysis compares human demands on
nature with the biosphere's ability to regenerate resources and provide
services. It does this by assessing the biologically productive land and marine
area required to produce the resources a population consumes and absorb the
corresponding waste, using prevailing technology. Footprint values at the end
of a survey are categorized for Carbon, Food, Housing, and Goods and Services
as well as the total footprint number of Earths needed to sustain the world's
population at that level of consumption. This approach can also be applied to
an activity such as the manufacturing of a product or driving of a car. This
resource accounting is similar to life cycle analysis wherein the consumption of energy, biomass (food, fiber), building
material, water
and other resources are converted into a normalized measure
of land area called global hectares (gha).
Per capita ecological footprint (EF), or ecological
footprint analysis (EFA), is a means of comparing consumption and lifestyles,
and checking this against nature's ability to provide for this consumption. The
tool can inform policy by examining to what extent a nation uses more (or less)
than is available within its territory, or to what extent the nation's
lifestyle would be replicable worldwide. The footprint can also be a useful
tool to educate people about carrying
capacity and over-consumption, with the aim of altering personal
behavior. Ecological footprints may be used to argue that many current
lifestyles are not sustainable. Such a global comparison also
clearly shows the inequalities of resource use on this planet at the beginning
of the twenty-first century.
In 2007, the average biologically productive area per person
worldwide was approximately 1.8 global
hectares (gha) per capita. The U.S.
footprint per capita was 9.0 gha, and that of Switzerland
was 5.6 gha, while China's
was 1.8 gha. The WWF claims that the human footprint has
exceeded the biocapacity (the available supply of natural resources)
of the planet by 20%. Wackernagel and Rees originally estimated that the
available biological capacity for the 6 billion people on Earth at that time
was about 1.3 hectares per person, which is smaller than the 1.8 global
hectares published for 2006, because the initial studies neither used global
hectares nor included bioproductive marine areas.
A number of NGOs offer ecological footprint calculators (see
Footprint Calculator, below).
Ecological footprint analysis is now widely used around the
Earth as an indicator of environmental sustainability.
It can be used to measure and manage the use of resources throughout the
economy. It can be used to explore the sustainability of individual lifestyles,
goods and services, organizations, industry sectors, neighborhoods, cities,
regions and nations. Since 2006, a first set of ecological footprint standards
exist that detail both communication and calculation procedures.
Methodology
The ecological footprint accounting method at the national
level is described in the l Footprint Atlas 2010 or in greater detail in the
Calculation Methodology for the National Footprint Accounts. The National
Accounts Review Committee has also published a research agenda on how the
method will be improved.
There have been differences in the methodology used by
various ecological footprint studies. Examples include how sea area should be
counted, how to account for fossil fuels, how to account for nuclear power
(many studies simply consider it to have the same ecological footprint as
fossil fuels),which data sources used, when average global numbers or local
numbers should be used when looking at a specific area, how space for
biodiversity should be included, and how imports/exports should be accounted
for. However, as new footprint standards emerge, the calculation methodologies
are converging.
In 2003, Jason Venetoulis, Carl Mas, Christopher Gaudet,
Dahlia Chazan, and John Talberth developed Footprint 2., which offers a series
of theoretical and methodological improvements to the standard footprint
approach. The four primary improvements were that they included the entire
surface of the Earth in biocapacity estimates, allocated space for other (i.e.,
non-human) species, updated the basis of equivalence factors from agricultural
land to net primary productivity (NPP), and refined the carbon component of the
footprint based on the latest global carbon models.
Studies in the United Kingdom
The UK's average ecological footprint is 5.45 global
hectares per capita (gha) with variations between regions ranging from 4.80
gha (Wales) to 5.56 gha (East England).Two recent studies have examined
relatively low-impact small communities. BedZED, a 96-home mixed-income housing development in South London, was
designed by Bill Dunster Architects and sustainability consultants BioRegional
for the Peabody Trust. Despite being populated by relatively
"mainstream" home-buyers, BedZED was found to have a footprint of
3.20 gha due to on-site renewable energy production, energy-efficient
architecture, and an extensive green lifestyles program that included on-site
London's first carsharing club. The report did not measure the added
footprint of the 15,000 visitors who have toured BedZED since its completion in
2002. Findhorn Ecovillage, a rural intentional community in Moray, Scotland, had a
total footprint of 2.56 gha, including both the many guests and visitors who
travel to the community to undertake residential courses there and the nearby
campus of Cluny
Hill College. However, the residents alone have a footprint of 2.71 gha, a
little over half the UK national average and one of the lowest ecological
footprints of any community measured so far in the industrialized world Keveral
Farm, an organic farming community in Cornwall, was found to have a footprint
of 2.4 gha, though with substantial differences in footprints among community
members.
Discussion
Early criticism was published by van den Bergh and
Verbruggen in 1999; another criticism was published in 2008. A more complete
review commissioned by the Directorate-General
for the Environment (European Commission) and published in June 2008
provides the most updated independent assessment of the method. A number of
countries have engaged in research collaborations to test the validity of the
method. This includes Switzerland, Germany, United Arab Emirates, and Belgium.
Grazi et al. (2007) have performed a systematic comparison
of the ecological footprint method with spatial welfare analysis that includes
environmental externalities, agglomeration effects and trade
advantages. They find that the two methods can lead to very distinct, and even
opposite, rankings of different spatial patterns of economic activity. However,
this should not be surprising, since the two methods address different research
questions.
Calculating the ecological footprint for densely populated
areas, such as a city or small country with a comparatively large population —
e.g. New York and Singapore respectively — may lead to the perception of these
populations as "parasitic". This is because these communities have
little intrinsic biocapacity, and instead must rely upon large hinterlands.
Critics argue that this is a dubious characterization since mechanized rural
farmers in developed nations may easily consume more resources than urban
inhabitants, due to transportation requirements and the unavailability of economies of scale. Furthermore, such moral
conclusions seem to be an argument for autarky. Some
even take this train of thought a step further, claiming that the Footprint
denies the benefits of trade. Therefore, the critics argue that the Footprint
can only be applied globally.
The method seems to reward the replacement of original
ecosystems with high-productivity agricultural monocultures
by assigning a higher biocapacity to such regions. For example, replacing
ancient woodlands or tropical forests with monoculture forests or plantations
may improve the ecological footprint. Similarly, if organic
farming yields were lower than those of conventional methods, this could
result in the former being "penalized" with a larger ecological
footprint. Of course, this insight, while valid, stems from the idea of using
the footprint as one's only metric. If the use of ecological footprints are complemented
with other indicators, such as one for biodiversity,
the problem could maybe be solved. Indeed, WWF's Living Planet Report complements the biennial
Footprint calculations with the Living Planet Index of biodiversity. Manfred
Lenzen and Shauna Murray have created a modified Ecological Footprint that
takes biodiversity into account for use in Australia.
Although the ecological footprint model prior to 2008
treated nuclear power in the same manner as coal power, the
actual real world effects of the two are radically different. A life cycle
analysis centered on the Swedish Forsmark Nuclear Power Plant estimated
carbon dioxide emissions at 3.10 g/kWh and 5.05 g/kWh in 2002 for the Torness Nuclear Power Station. This
compares to 11 g/kWh for hydroelectric power, 950 g/kWh for installed coal, 900
g/kWh for oil and 600 g/kWh for natural gas generation in the United States in
1999. Figures released by Mark Hertsgaard, however, show that because of the
delays in building nuclear plants and the costs involved, investments in energy
efficiency and renewable energies have seven times the return on investment of
investments in nuclear energy.
The Swedish utility Vattenfall
did a study of full life cycle emissions of Nuclear, Hydro, Coal, Gas, Solar
Cell, Peat and Wind which the utility uses to produce electricity. The net
result of the study was that nuclear power produced 3.3 grams of carbon
dioxide per KW-Hr of produced power. This compares to 400 for natural gas
and 700 for coal
(according to this study). The study also concluded that nuclear power produced
the smallest amount of CO2 of any of their electricity sources.
Claims exist that the problems of nuclear waste do not come
anywhere close to approaching the problems of fossil fuel waste. A 2004 article
from the BBC states: "The World Health Organization (WHO) says 3
million people are killed worldwide by outdoor air pollution annually from
vehicles and industrial emissions, and 1.6 million indoors through using solid
fuel." In the U.S. alone, fossil fuel waste kills 20,000 people each year.
A coal power plant releases 100 times as much radiation as a nuclear power
plant of the same wattage. It is estimated that during 1982, US coal burning
released 155 times as much radioactivity into the atmosphere as the Three
Mile Island incident. In addition, fossil fuel waste causes global
warming, which leads to increased deaths from hurricanes, flooding, and
other weather events. The World Nuclear Association provides a
comparison of deaths due to accidents among different forms of energy
production. In their comparison, deaths per TW-yr of electricity produced (in
UK and USA) from 1970 to 1992 are quoted as 885 for hydropower, 342 for coal,
85 for natural gas, and 8 for nuclear.
Footprint by country
The world-average ecological footprint in 2007 was 2.7
global hectares per person. The average per country ranges from over 10 to
under 1 hectares per person. There is also a high variation within countries,
based on individual lifestyle and economic situation.]
The GHG footprint differs from the ecological footprint
in that the former is expressed in units of GHG warming potential (GGWP) and is
generated by products or services, whereas the latter is expressed in units of
land area and is generated by whole societies.
SUBSCRIBERS - ( LINKS) :FOLLOW / REF / 2 /
findleverage.blogspot.com
Krkz77@yahoo.com
+234-81-83195664
No comments:
Post a Comment