Living within a Fair Share Ecological Footprint

Robert Vale, Brenda Vale

• Publisher: Routledge
• Year: 2013
• Print ISBN: 9780415507226
• eBook ISBN: 9781136456060
• Topic: Ciencias biológicas
• Subtopic: Ecología

According to many authorities the impact of humanity on the earth is already overshooting the earth's capacity to supply humanity's needs. This is an unsustainable position. This book does not focus on the problem but on the solution, by showing what it is like to live within a fair earth share ecological footprint.

The authors describe numerical methods used to calculate this, concentrating on low or no cost behaviour change, rather than on potentially expensive technological innovation. They show what people need to do now in regions where their current lifestyle means they are living beyond their ecological means, such as in Europe, North America and Australasia. The calculations focus on outcomes rather than on detailed discussion of the methods used. The main objective is to show that living with a reduced ecological footprint is both possible and not so very different from the way most people currently live in the west.

The book clearly demonstrates that change in behaviour now will avoid some very challenging problems in the future. The emphasis is on workable, practical and sustainable solutions based on quantified research, rather than on generalities about overall problems facing humanity.

Part I

Introduction

1 Ecological Footprints, Fair Earth-Shares and Urbanization

William E. Rees and Jennie Moore

Introduction: Thinking about Urban Sustainability

Economic expansionists often argue that environmentalists exaggerate the human impact on earth. After all, humans are increasingly an urban species and cities occupy only 2 to 3 per cent of earth's land area; the entire human population could live in the US state of Texas in single-family dwellings with room to spare! Some economists even suggest that humanity's impact may actually be shrinking as people get richer and the economy ‘dematerializes’ or ‘decouples’ from nature.

One purpose of this chapter is to make the case that most such claims are the result of faulty accounting. The simple fact is that the geographic or political ‘footprints’ of human settlements bear scant relationship to the biophysical demands of their inhabitants on the ecosphere (Rees, 2010a, 2012). Contrary to common belief, urbanization is not further evidence that humanity is decoupling from nature. Urbanization merely separates people spatially from their supportive ecosystems without changing their functional dependence on those systems. In other words, urbanization effectively divides the human ecosystem into two distinct physical components – a widely dispersed productive ‘hinterland’ and a densely concentrated but wholly dependent consumptive core, the city itself. The increasingly global hinterland of a typical modern city – its true ‘ecological footprint’, or EF – is up to three orders of magnitude (a thousand times) larger than the city itself. From a human ecological perspective – all fantasies of Texas aside – we actually live in an ecologically full world (Daly, 2005).

Indeed, earth is full to overflowing. Recent estimates put humanity's aggregate ecological footprint at approximately 18 billion global hectares, or 2.7 global hectares (gha) per capita (a ‘global hectare’ represents a hectare of land or water ecosystems of world average productivity). Compare this to the earth's total stock of productive land and water ecosystems: 11.9 billion gha, or 1.7 gha per capita (WWF, 2010a). Humanity has already overshot global carrying capacity by roughly 50 per cent. This overshoot is made possible by using non-renewable resources; it means that our species is living and growing, in part, by depleting ecosystems and resource stocks, polluting air, water and soil, and undermining both local and global life-support functions. We are dissipating essential ‘natural capital’ and generally disordering the ecosphere. This situation demands that the world community thoroughly and urgently rethink its growth-based economic paradigm.

The primary cause of global degradation is resource over-consumption and excess waste production. Since, first, the wealthiest fifth of the world's people account for 76 per cent of private consumption and associated pollution (Shah, 2010) and, second, total human demand exceeds long-term bio-capacity by 50 per cent, the richest 20 per cent alone have effectively appropriated the entire bio-capacity of earth and contribute most to its degradation. This fortunate minority mostly comprises those living in industrial and post-industrial cities with average eco-footprints several times larger than their equitable shares of global carrying capacity.

Within this context, the major purposes of this chapter are to make the case, on both thermodynamic and ecological footprint (EF) grounds, that:

1 It is meaningless to plan for urban sustainability without ensuring the security and sustainability of the extra-urban ecosystems upon which cities are dependent.

2 Achieving equitable global sustainability in an urbanizing world will require significant reductions in energy and material throughput.

We argue that the world community has no choice but to reconcile the prevailing myth of unlimited economic growth with a rapidly deteriorating biophysical reality. Ecosystems can thrive in the absence of the economy, but no economy is possible without fully functional ecosystems. If we wish to extend the lifetime of global civilization on a finite planet, the world community must constrain its energy and material demands to comply with the limits set by the productive and assimilative capacities of our life-supporting ecosystems.

Clearly, sustainability is a serious business, more serious than most governments and international agencies have so far been willing to contemplate. The failure of the 2012 ‘Rio +20’ conference is strong evidence of this (Monbiot, 2012). Starting with a world in overshoot, equitable sustainability implies that wealthy countries should already be implementing plans to reduce their per capita ecological footprints – by up to 80 per cent. Major reductions in throughput by the wealthy are necessary to create the ecological space needed for justifiable consumption growth in developing countries (Rees, 2008). This is the true biophysical meaning of the emergent concept of ‘degrowth’ that is now spreading virally around the world.

Cities, the Second Law and Urban Ecosystems

The modern city – its form, function and sheer scale in the landscape – has been made possible because of abundant cheap energy, particularly fossil fuels. There may be no better expression of human technical mastery of materials than the multiple transportation, communication, utility and other engineered systems that comprise the circulatory, digestive, nervous and waste disposal infrastructure of typical large cities.

Until recently, we have not had to think much about it, but the energy intensity and ‘physicalness’ of cities make them subject to the rigorous rule of the second law of thermodynamics, the entropy law. The second law is implicated in all real processes involving the use of energy and the transformation of materials.

Even if they have never heard of it, everyone is familiar with commonplace examples of the second law at work – every shiny new car eventually becomes a rusty old clunker; in plain English, the second law dictates that, without continuous maintenance, things naturally tend to erode, wear out and run down. And there are no known exceptions. Is anyone aware of a rusted-out old car that has reacquired its original showroom splendour all on its own?

Scientists describe the second law in slightly more technical terms: any spontaneous change in an isolated system (one not able to exchange energy or matter with its ‘environment’) increases the ‘entropy’ of that system. By this they mean that, over time, the system tends to lose form and function – ‘randomness’ increases as order erodes and energy dissipates. Eventually, an isolated system will reach ‘thermodynamic equilibrium’, a state of maximum entropy in which no further change is possible. Entropy is one of the more difficult concepts in physics. For our purposes, it is sufficient to define entropy as a measure of disorder or randomness. Thus, a completely dissipated system exhibits maximum entropy, while a highly ordered system is a low-entropy system. Concentrations of ‘available’ or useful energy or matter are sometimes called ‘negentropy’.

Of course, the real world is full of complex systems, ranging from newborn infants through cities to the entire ecosphere, which are assuredly not decaying toward equilibrium. The ecosphere, for example, is a highly ordered system of extraordinary complexity, as represented by millions of distinct species, differentiated matter and accumulated biomass. Moreover, with the passage of geological time, its biodiversity, systemic complexity and energy/material flows have been increasing. In short, the ecosphere is seemingly evolving against the gradient of decay imposed by thermodynamic law. It has been rising ever further from equilibrium; the entropy of the system is decreasing (see Box 1.1). Prigogine (1997) asserts that this phenomenon may well be the measure of life: ‘distance from equilibrium becomes an essential parameter in describing nature, much like temperature [is] in [standard] equilibrium thermodynamics’.

If all energy and material transformation is governed by the entropy law, how can we explain the ascent of the ecosphere? The paradox hinges on a single fact: all living systems, from the tiny organelles inside living cells to entire ecosystems, from cities to the ecosphere, are open systems that freely exchange energy and matter with their environments. In short, open systems are just as subject to degradation as isolated systems are but they are also able to import high-grade energy and raw materials for self-maintenance and growth, and to export the resultant low-grade wastes. In effect, open systems can shed their entropy into their ‘environments’ (see Box 1.1).

Box 1.1 The ecosphere and the second law

Imagine a homogenized world the surface layers of which contain exactly the same mass and mix of elements and stable compounds (for example water and carbon dioxide) as the real world, but where everything has been put through an entropic blender. In this imaginary world there are no concentrations of anything – no physical means of distinguishing any point in ‘the system’ from any other. Our randomized world is at thermodynamic equilibrium, a state of maximum local entropy.

Now imagine the enormous task of replicating the living world as we know it from this homogeneous mass of raw material: all the necessary ‘stuff’ is there, but consider the unfathomable quantity of external energy and the infinity of physical processes that would be required to assemble, molecule by molecule, the mind-boggling diversity and complexity (negentropy) of present-day earth from our simulated primordial soup and then maintain it there against the inexorable drag of the entropy law.

In fact, this massive expenditure of energy and effort has actually occurred, or else we wouldn't be here thinking about it! Where did the necessary energy come from? Initially, the process – the emergence of the first replicating molecules and single-celled organisms – was driven by residual chemical energy in the ‘soup’, but for the past 2.5 billion years the growth and evolution of the ecosphere has mostly been powered by solar energy. No sun, no ecosphere.

Green plants, using photosynthesis, assimilate and incorporate a small portion of this available high-grade solar energy (negentropy) as chemical energy in plant biomass. This concentration of energy and matter powers all other life-forms and living processes in the ecosphere. Much more of the energy falling on plants is used in evapotranspiration to cool them down. Thus, through photosynthesis, evapotranspiration and their own respiration, plants radiate vast quantities of low-grade, high-entropy waste heat into space. Consumer organisms (mostly animals, bacteria and fungi) produce themselves by consuming the surplus biomass (negentropy) generated by plants, but they also ultimately dissipate all this chemically bound solar energy back into space in degraded form. The ecosphere emerges in all its negentropic splendour, but the net entropy of the universe increases much more in the process.

Primary lessons? First, in a universe governed by the second law of thermodynamics, any system that achieves and maintains a highly differentiated, far-from-equilibrium dynamic steady state or which continues growing must have a constant, reliable source of external energy to enable it to resist the dissipative drag of the second law. Second, the increase in local negentropy represented by the growth and increase in complexity of any subsystem is purchased at the expense of a much larger increase in global entropy.

There are, of course, complications. Systems biologists recognize that living systems exist in overlapping, nested hierarchies in which each component subsystem (called a ‘holon’) is contained by the next level up and itself comprises a chain of linked subsystems at lower levels. (Think ‘cell, tissue, organ, individual, population, community, ecosystem’ or, if you prefer, contemplate a set of Russian ‘matryoshka’ nesting dolls.)

This organizational form is the basis for ‘self-organizing holarchic open’ (SOHO) systems theory (Kay and Regier, 2000). ‘Holarchic’ means a hierarchy of holons, and the key idea is that every holon in the hierarchy grows, develops and maintains itself using available energy and material (negentropy) extracted from its ‘host’ system one level up. It processes this energy and matter internally to produce and maintain its own structure and function, and exports its degraded energy and material wastes back into its environment. In short, living organisms maintain themselves in low-entropy far-from-equilibrium states at the expense of increasing global entropy, particularly the entropy of their immediate host system (Schneider and Kay, 1994, 1995). Because self-producing systems thrive by continuously importing, degrading and dissipating available energy and matter, they are called ‘dissipative structures’ (Prigogine, 1997).

Another expression of the second law is relevant to this discuss...

Table of contents

• Cover
• Title Information
• Title Page
• Copyright Page
• Table of Contents
• Notes on contributors
• Preface
• Part I Introduction
• Part II What Does Living within a Fair Earth Share Mean?
• Part III Footprints in the Past
• Part IV Footprints in the Present
• Part V Conclusions
• Index