urban ecology australia - do we fit on the planet

7/29/2019 Urban Ecology Australia - Do We Fit on the Planet

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Do We Fit On The Planet?

Food Systems and the Ecological Footprint

Sharon Ede, Urban Ecology Australia, 2002.4

(Available in http://www.urbanecology.org.au/articles/dowefit.html)

All human beings, whatever their lifestyles, generate impacts on nature, butthis is not a concern provided our impacts are within the means of nature, thatis within the regenerative capacity of the biosphere.

Concerns over resource use have previously focused on the depletion of finitenonrenewable resources such as fossil fuels and minerals, however it isincreasingly recognised that it is renewable resources which are the non-negotiable limiting factors for sustaining life.

Historically, countries have sustained economic growth by appropriatingbiocapacity (resources, ecological services, waste sinks) from elsewherethrough purchasing power, with some waste such as CO2 and CFCs being‘dumped’ into the global commons.

However this model of dependence on ‘ghost acreage’ (biocapacity on whicha country depends, but which is not physically within the borders of thatcountry), which has both the developed and developing world alike in its grasp,ignores one simple reality – not everyone can be a net importer of biocapacity .

Once the biological carrying capacity of the planet is exceeded, ‘development’

occurs through the liquidation of the planet’s natural capital stock, switchingfrom the reproductive use of the resource base, which leaves it intact, to anextractive use, which reduces the total store. Instead of living off the Earth’s‘interest’, humanity begins draining the Earth's 'capital', and we move intowhat is termed ‘ecological overshoot’.

Overshoot graphic by Phil Testemale (in Rees & Wackernagel, 1996)



Overshoot is when human demand exceeds nature’s supply at the local,national, or global scale. The level of overshoot is the amount by whichnature’s biological capacity is being used beyond its regeneration rate.

Sustainability

Sustainability has a specific meaning - avoiding ecological overshoot.

The myriad of ‘fuzzy’ definitions attributed to sustainability keeps discussionsvague, and diffuses the pressure for action.

‘Fuzzy’ terms include 'sustainable development' and its omnipresentBrundtland definition ‘meeting the needs of the present without compromisingthe ability of future generations to meet their needs’.

This definition is problematic - how do we know how many people there will bein future generations, and what their needs will be? Also, many societiestoday are not just meeting needs, but wants - should future generations be

allowed to fulfil their wants as well as their needs?

Defining sustainability in a way which is both specific and measurablenecessitates keeping of biophysical accounts to enable us to determinewhether we are moving into or avoiding overshoot.

It would be unthinkable to run a business without keeping the books - abusiness which does not track its activities and keep accurate financialrecords runs the risk of bankruptcy - yet this is precisely the approach we takewith the only planet within our reach capable of supporting life.

Footprints As Resource Accounting Tools

Resource accounting tools are needed to monitor humanity’s use of nature inorder to answer what may be the most important question which has ever confronted our political, social and economic institutions: do we fit on theplanet?

Ecological Footprinting measures human use of nature and aggregates our impacts on the biosphere into one figure, the bioproductive space occupiedexclusively by a given human activity, expressed in hectares.

Footprinting inverts the traditional concept of carrying capacity, the population

a given region could support, and instead seeks to determine ecological load -what total area of land is required, regardless of where that land is located, tosustain a given population, organisation or activity.

National Footprints are underpinned by complex spreadsheets designed toenable calculation of a country’s per capita Footprint (demand), and compareit with the biocapacity (supply) of the country and planet.



Official data from the UN Food & Agriculture Organisation, theIntergovernmental Panel on Climate Change, and a range of other reputablesources, such as the World Resources Institute, form the basis of nationalFootprint accounts.

The spreadsheets track a country’s production, import, export and apparent

consumption of approximately 60 categories of commodities in biophysicalunits (eg. tonnes) rather than monetary units, and each category includes bothprimary resources (raw timber or milk) and manufactured products that arederived from them (paper or cheese).

Conversion factors are used to account for the efficiency of conversion of rawmaterials (eg. milk) to manufactured products (eg. cheese). Adjustedconversion factors correct true conversion efficiencies to account for secondary animal products, such as hides and wool.

Direct comparison of actual land area raises an equity issue, as countrieshave access to different land types of varying quality. Figures are corrected

for bioproductivity by multiplying the actual area of land (hectares) by anequivalence factor to produce ‘area units’.

The equivalence factor represents the productivity of a category of landglobally as compared to ‘average’ land globally ie. arable land is scaled up inrelation to ‘average’ space, as it is more biologically productive.

Biocapacity figures are also corrected using a yield factor, which illustrateshow much more or less productive a country’s land is in comparison to samecategory across the rest of the world.

Footprint results underestimate human impact and overestimate availablebiological capacity by choosing conservative estimates when in doubt, leavingout some activities for which there is insufficient data, assuming currentagricultural yields are sustainable and excluding activities that systematicallyerode nature’s ability to regenerate, eg. use of materials for which thebiosphere has no significant assimilation capacity, such as plutonium,polychlorinated biphenyls (PCBs), chlorofluorocarbons (CFCs), and processesthat irreversibly damage the biosphere eg. species extinction, aquifer destruction, deforestation, desertification.

Even with this cautious approach, research undertaken by RedefiningProgress using Ecological Footprint analysis reveals that in 1996, the average

Footprint per person was 2.85 hectares. However there are only 2.2 hectaresper person available globally.

Biologically productive space needed to support6 billion people living on a 2.85 hectare Footprint(1996)

17.1 billionhectares

Biologically productive space on the planet(1996)

12.6 billionhectares



Number of planets needed to sustain 6 billionpeople living on a 2.85 hectare Footprint

1.35

A time series which calculates the global Footprint and global biocapacity for every year from 1961 – 1997 has been developed by Oakland basedRedefining Progress (www.rprogress.org). The series reveals that some time

during the mid- 1970s, humanity crossed over from a reproductive to anextractive use of nature.

By 1997, humanity’s footprint had exceeded global carrying capacity by over 30%. This means that one and a third planets are currently required to sustainhumanity ie. nature takes one year and four months to regenerate thebioproductive capacity we use in a year.

0 2 (Figure showingecological footprint; available biocapacity; available biocapacity allowing 10%for nature reserves.)

The question is not whether we can sustain more than six billion people on awestern industrial model of development, but how to sustain the projectedglobal population at an adequate standard of living for all within theregenerative biocapacity of one planet.

Furthermore, it is vital that a percentage of the earth be set aside to allow

bioproductive space for the millions of other species that share the planet withhumanity, and whom we typically exclude from the spaces occupied for human uses. The Footprint methodology uses the 1987 Brundtland reportfigure of 12% - an estimate considered to be politically courageous butecologically inadequate, as conservation biologists think the necessary figureis more likely to be somewhere between 25- 75%.

Competition for biocapacity occurs not only between species, but betweeneconomies. As the Footprint is an aggregated indicator which highlights the



connections of ecological functions and human pressures on nature, it canreveal competition for ecological space. Once the Footprint exceeds biologicalcapacity, human uses of nature become competitive with each other.

Alleviating one pressure may simply shift the load elsewhere, or one impactmay even exacerbate another.

Because the Footprint is an accounting tool based on physical rather thanmonetary data, it can provide us with crucial information pertaining to resourceuse and ecological limits which is absent from conventional economic analysis.

‘… market scarcity and ecological scarcity are increasingly separate phenomena, the former representing the immediate supply on the market (asexpressed by market prices), the latter giving an indication of total existing stocks (as expressed in biophysical accounts). As global trade delinks market scarcity and ecological scarcity, the healthy and necessary feedback loopbetween ecological capacity and human consumption is broken…’

Mathis Wackernagel

As the demand for biocapacity grows while the supply shrinks, tracking use of nature is imperative both for countries with an ecological deficit who aredependent on imported carrying capacity, as well as for ecological creditorswho are supplying the debtors with biocapacity, often through liquidating their own natural capital.

The Ecological Footprint enables us to understand sustainability in a way thatis both measurable, and grounded within ecological realities.

Cities and ‘Food Footprints’

Cities have enormous potential as leverage points for change - not only isover half of humanity now living in urban areas worldwide, but developmentand the making of cities is the single most powerful source of impacts on theplanet.

Creating and maintaining the built environment generates massive amounts of resource extraction and use, and it is imperative that we understand the cityas an ecosystem, acknowledging and addressing the behaviour of thesemega-organisms, and their impact beyond city limits.

In the mid 1990s, Herbert Girardet (author of the Gaia Atlas of Cities)estimated the Ecological Footprint of London, and found that it was 125 timesthe actual surface area of London.



We need to understand how and where our cities are appropriating andaltering other areas of earth to service their needs:

‘Estimates at the time of the Earth Summit (Rio) in 1992 found that 75 percent of the natural resources that we harvest and mine from the Earth are shipped,

trucked, railroaded and flown to 2.5 percent of the Earth’s surface, which ismetropolitan. At that destination, 80 percent of those resources are converted into ‘waste’.’

Jac Smit, ‘Urban Agriculture & Biodiversity’

Cities and urban areas, with their immense economic and political power, arecentral to global and local ecological problems, and they must become centralto solutions. As largely urban creatures, people need to understand and takeresponsibility for the patterns of how cities behave in nature, their relationshipto their regions, how urban demands generate environmental problems andhow this dynamic can be harnessed for the purposes of ecological

development and restoration.

(City footprint graphic by Phil Testemale (in Rees & Wackernagel, 1996)

The Footprint concept can be used to help us explore ways of making our cities not only as ecologically benign as possible, but as productive (or ‘biogenic’) rather than ‘biocidic’ (or destructive) in form and function.

Ecological Load of Urban Food Systems



Human settlements depend upon agriculture for survival, however few citydwellers are ever faced with the effects their lives make on areas beyond thecity limits, such as the consequences of large scale agriculture required tofeed the hordes of urban dwellers, the impacts generated by growing,amassing and transporting resources required for consumption in the city.

‘… with access to global resources, urban populations everywhere areseemingly immune to the consequences of locally unsustainable land and resource management practices...’ William Rees & Mathis Wackernagel

Environmental impacts resulting from food production - such as drylandsalinity, demand for water, runoff of pesticides and fertilisers made necessaryby centralised production/monocultural agribusiness – are predominantlygenerated by the demands of urban markets.

Food production systems which are dependent on extensive external supplylines are also a large contributor to ‘food miles’, greenhouse emissionsresulting from fossil fuel consumption required for transport & refrigeration.

‘Economics, particularly so-called economic rationalism is supposed to beabout the efficient use of resources – what more gross misallocation of resources and human effort could there be than shipping low valueagricultural produce such as strawberries halfway around the planet?'

Michael Rowbotham, August 2001, Community Economics Conference, Adelaide

(Africa image by P V Vernon from ‘Sharing Nature’s Interest’ (2000) by NickyChambers, Craig Simmons & Mathis Wackernagel

http://www.ecologicalfootprint.com)

The emergence of global trade and its network of extensive external supplylines has resulted in an enormous expansion of humanity’s ‘food footprint’,particularly in terms of food miles.

Transporting food into the city from often distant locations has greenhouseimplications – the further we have to transport it in (or out), the higher theembodied energy of our food. This is a significant issue in relation to the cost



of fuel and its effect on availability and affordability of food, particularly in theface of any future oil shocks.

Urban Agriculture

‘… agriculture and food consumption is the largest contributor to humanity’s

ecological load, appropriating over 60 percent of the planet’s regenerativecapacity...’

Mathis Wackernagel & Diana Deumling

There is growing recognition that urban agriculture can meet a percentage of urban dwellers’ food needs within urban areas. Urban food production(including permaculture, roof & community gardens) may be the mostpowerful tool we have to close open nutrient, carbon and pollution loops whilecontributing positively to local and regional economic activity. Urbanagriculture could also assist in arresting and reversing biodiversity loss:

‘One acre of urban agriculture, using urban waste as an input, can save fiveacres, or more, of rural marginal agricultural land or rain forest…Urbanagriculture is an effective tool to slow down the loss of biodiversity’

Jac Smit, ‘Urban Agriculture & Biodiversity’

Incorporating urban food production into food systems has many potentialbenefits – reduction of greenhouse gas emissions and a range of other environmental impacts, protection of biodiversity, local economic stimulation,nutritional & other health benefits, reduction of urban heat islands, communitybuilding through people working together, and neighbourhood security as a

result of passive surveillance.

Perhaps most importantly, Ecological Footprinting can help to re-establishhumanity’s psychological connection to nature by measuring and makingvisible impacts which have largely been rendered ‘ unseen’.

Produced by Sharon Ede for Urban Ecology Australia’s 10th BirthdayCelebration Bioregional Banquet, 21 April 2002

References

Wackernagel, Mathis & Rees, William (1996) Our Ecological Footprint–

Reducing Human Impact on the Earth New Society Publishers, GabriolaIsland, Canada

Wackernagel, Mathis (2000) ‘Importing Carrying Capacity: How Global TradeEnables Nations and the World to Accumulate and Ecological Debt’Contribution to Professor Kenneth Watt’s Encyclopaedia on Human Ecology,Transaction Publishers/ Rutgers, New Jersey, US.



Wackernagel, Mathis (2001) ‘Advancing Sustainable Resource Management:Using Ecological Footprint Analysis for Problem Formulation, PolicyDevelopment and Communication’ Draft Paper prepared for DGXI, EuropeanCommission Redefining Progress, Oakland.

Wackernagel, Mathis & Deumling, Diana (2001) ‘Eating up the Earth: How

Sustainable Food Systems Reverse Humanity’s Assault on the Biosphere’Draft outline for a briefing paper for the philanthropic community on theecological significance of sustainable food systems Redefining Progress,Oakland.

Wackernagel, Mathis; Yount, David & Deumling, Diana (2000) ‘Accounting for the Future: A Handbook for National (and Regional) Ecological Footprint Analysis’ Draft Redefining Progress, Oakland.

Author

Sharon Ede, an Urban Ecology Australia Board Member who works for theSouth Australian Department for Environment & Heritage, undertookresearch/study in May 2001 with California based organisation RedefiningProgress, whose Sustainability Program is directed by Mathis Wackernagel,one of the Footprint’s creators.

2007.2.8

urban ecology australia - do we fit on the planet

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