Chapter 1. Introduction to Sustainability: Humanity and the Environment
1.1. An Introduction to Sustainability: Humanity and the Environment*
Learning Objectives
After reading this chapter, students should be able to
learn the meaning of sustainability in its modern context
acquire a basic facility for using the IPAT equation
learn about patterns of human consumption
understand the major factors that contribute to unsustainable impacts
1.2. What is Sustainability?*
In 1983 the United Nations General Assembly passed resolution 38/161 entitled “Process of Preparation of the Environmental Perspective to the Year 2000 and Beyond,” establishing a special commission whose charge was:
To propose long-term environmental strategies for achieving sustainable development to the year 2000 and beyond;
To recommend ways in which concern for the environment may be translated into greater co-operation among developing countries and between countries at different stages of economic and social development and lead to the achievement of common and mutually supportive objectives which take account of the interrelationships between people, resources, environment and development;
To consider ways and means by which the international community can deal more effectively with environmental concerns, in the light of the other recommendations in its report;
To help to define shared perceptions of long-term environmental issues and of the appropriate efforts needed to deal successfully with the problems of protecting and enhancing the environment, a long-term agenda for action during the coming decades, and aspirational goals for the world community, taking into account the relevant resolutions of the session of a special character of the Governing Council in 1982.
The commission later adopted the formal name “World Commission on Environment and Development” (WCED) but became widely known by the name of its chair Gro Harlem Brundtland, a medical doctor and public health advocate who had served as Norway’s Minister for Environmental Affairs and subsequently held the post of Prime Minister during three periods. The commission had twenty-one members drawn from across the globe, half representing developing nations. In addition to its fact-finding activities on the state of the global environment, the commission held fifteen meetings in various cities around the world seeking firsthand experiences on the how humans interact with the environment. The Brundtland Commission issued its final report “Our Common Future” in 1987.
Although the Brundtland Report did not technically invent the term “sustainability,” it was the first credible and widely-disseminated study that probed its meaning in the context of the global impacts of humans on the environment. Its main and often quoted definition refers to sustainable development as “…development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” The report uses the terms “sustainable development,” “sustainable,” and “sustainability” interchangeably, emphasizing the connections among social equity, economic productivity, and environmental quality. The pathways for integration of these may differ nation by nation; still these pathways must share certain common traits: “the essential needs of the world's poor, to which overriding priority should be given, and the idea of limitations imposed by the state of technology and social organization on the environment's ability to meet present and future needs.”
Thus there are three dimensions that sustainability seeks to integrate: economic, environmental, and social (including sociopolitical). Economic interests define the framework for making decisions, the flow of financial capital, and the facilitation of commerce, including the knowledge, skills, competences and other attributes embodied in individuals that are relevant to economic activity. Environmental aspects recognize the diversity and interdependence within living systems, the goods and services produced by the world’s ecosystems, and the impacts of human wastes. Socio-political refers to interactions between institutions/firms and people, functions expressive of human values, aspirations and well-being, ethical issues, and decision-making that depends upon collective action. The report sees these three elements as part of a highly integrated and cohesively interacting, if perhaps poorly understood, system.
The Brundtland Report makes it clear that while sustainable development is enabled by technological advances and economic viability, it is first and foremost a social construct that seeks to improve the quality of life for the world’s peoples: physically, through the equitable supply of human and ecological goods and services; aspirationally, through making available the widespread means for advancement through access to education, systems of justice, and healthcare; and strategically, through safeguarding the interests of generations to come. In this sense sustainability sits among a series of human social movements that have occurred throughout history: human rights, racial equality, gender equity, labor relations, and conservation, to name a few.
The intersection of social and economic elements can form the basis of social equity. In the sense of enlightened management, "viability" is formed through consideration of economic and environmental interests. Between environment and social elements lies “bearability,” the recognition that the functioning of societies is dependent on environmental resources and services. At the intersection of all three of these lies sustainability.
The US Environmental Protection Agency (US EPA) takes the extra step of drawing a distinction between sustainability and sustainable development, the former encompassing ideas, aspirations and values that inspire public and private organizations to become better stewards of the environment and that promote positive economic growth and social objectives, the latter implying that environmental protection does not preclude economic development and that economic development must be ecologically viable now and in the long run.
The Chapter The Evolution of Environmental Policy in the United States presents information on how the three components that comprise sustainability have influenced the evolution of environmental public policy. The Chapter Sustainability: Ethics, Culture, and History explores in greater detail the ethical basis for sustainability and its cultural and historical significance.
1.3. The IPAT Equation*
As attractive as the concept of sustainability may be as a means of framing our thoughts and goals, its definition is rather broad and difficult to work with when confronted with choices among specific courses of action. The Chapter Problem-Solving, Metrics, and Tools for Sustainability is devoted to various ways of measuring progress toward achieving sustainable goals, but here we introduce one general way to begin to apply sustainability concepts: the IPAT equation.
As is the case for any equation, IPAT expresses a balance among interacting factors. It can be stated as
where I represents the impacts of a given course of action on the environment, P is the relevant human population for the problem at hand, A is the level of consumption per person, and T is impact per unit of consumption. Impact per unit of consumption is a general term for technology, interpreted in its broadest sense as any human-created invention, system, or organization that serves to either worsen or uncouple consumption from impact. The equation is not meant to be mathematically rigorous; rather it provides a way of organizing information for a “first-order” analysis.
Suppose we wish to project future needs for maintaining global environmental quality at present day levels for the mid-twenty-first century. For this we need to have some projection of human population (P) and an idea of rates of growth in consumption (A).
Figure World Population Growth suggests that global population in 2050 will grow from the current 6.8 billion to about 9.2 billion, an increase of 35%. Global GDP (Gross Domestic Product, one measure of consumption) varies from year to year but, using Figure Worldwide Growth of Gross Domestic Product as a guide, an annual growth rate of about 3.5% seems historically accurate (growth at 3.5%, when compounded for forty years, means that the global economy will be four times as large at mid-century as today).
Thus if we wish to maintain environmental impacts (I) at their current levels (i.e. I2050 = I2010), then
or
This means that just to maintain current environmental quality in the face of growing population and levels of affluence, our technological decoupling will need to reduce impacts by about a factor of five. So, for instance, many recently adopted “climate action plans” for local regions and municipalities, such as the Chicago Climate Action Plan, typically call for a reduction in greenhouse gas emissions (admittedly just one impact measure) of eighty percent by mid-century. The means to achieve such reductions, or even whether or not they are necessary, are matters of intense debate; where one group sees expensive remedies with little demonstrable return, another sees opportunities for investment in new technologies, businesses, and employment sectors, with collateral improvements in global and national well-being.
1.4. Human Consumption Patterns and the “Rebound” Effect*
In 1865 William Jevons (1835-1882), a British economist, wrote a book entitled “The Coal Question,” in which he presented data on the depletion of coal reserves yet, seemingly paradoxically, an increase in the consumption of coal in England throughout most of the 19th century. He theorized that significant improvements in the efficiency of the steam engine had increased the utility of energy from coal and, in effect, lowered the price of energy, thereby increasing consumption. This is known as the Jevons paradox , the principle that as technological progress increases the efficiency of resource utilization, consumption of that resource will increase. Increased consumption that negates part of the efficiency gains is referred to as “rebound,” while overconsumption is called “backfire.” Such a counter-intuitive theory has not been met with universal acceptance, even among economists (see, for example, “The Efficiency Dilemma”). Many environmentalists, who see improvements in efficiency as a cornerstone of sustainability, openly question the validity of this theory. After all, is it sensible to suggest that we not improve technological efficiency?
Whether or not the paradox is correct, the fact that it has been postulated gives us pause to examine in somewhat greater depth consumption patterns of society. If we let Q be the quantity of goods and services delivered (within a given time period) to people, and R be the quantity of resources consumed in order to deliver those goods and services, then the IPAT equation can be rewritten in a slightly different way as:
where 
represents the “resource intensity,” and 
is the impact created per unit of resources consumed. Rearranging this version of the equation gives:
which says simply that resources consumed are equal to the quantity of goods and services delivered times the resource intensity. The inverse of resource intensity
is called the resource use efficiency, also known as “resource productivity” or “eco-efficiency
,” an approach that seeks to minimize environmental impacts by maximizing material and energy efficiencies of production. Thus we can say:
that is, resources consumed are equal to goods and services delivered divided by eco-efficiency. Whether or not gains in eco-efficiency yield genuine savings in resources and lower environmental impacts depends on how much, over time, society consumes of a given product or service (i.e. the relative efficiency gain,
) must outpace the quantity of goods and services delivered
. In the terms of Jevons paradox, if
then the system is experiencing “backfire.”
Part of the problem in analyzing data pertaining to whether or not such “overconsumption” is happening depends on the specific good or service in question, the degree to which the data truly represent that good or service, and the level of detail that the data measure. Table Historical Efficiency and Consumption Trends in the United States summarizes some recent findings from the literature on the comparative efficiency and consumption for several activities over extended periods of observation. Taken collectively these activities capture several basic enabling aspects of modern society: major materials, transportation, energy generation, and food production. In all cases the data show that over the long term, consumption outpaces gains in efficiency by wide margins, (i.e.,
). It should also be noted that in all cases, the increases in consumption are significantly greater than increases in population. The data of Table Historical Efficiency and Consumption Trends in the United States do not verify Jevons paradox; we would need to know something about the prices of these goods and services over time, and examine the degree to which substitution might have occurred (for instance aluminum for iron, air travel for automobile travel). To see if such large increases in consumption have translated into comparable decreases in environmental quality, or declines in social equity, other information must be examined. Despite this, the information presented does show a series of patterns that broadly reflect human consumption of goods and services that we consider essential for modern living and for which efficiency gains have not kept pace; in a world of finite resources such consumption patterns cannot continue indefinitely.
| Activity | Time Period | Avg Annual Efficiency Improvement (%) | Avg Annual Increase in Consumption (%) | Ratio: Consumption/Efficiency |
|---|---|---|---|---|
| Pig Iron | 1800-1990 | 1.4 | 4.1 | 3.0 |
| Aluminum | 1900-2005 | 1.2 | 9.8 | 7.9 |
| Fertilizer | 1920-2000 | 1.0 | 8.8 | 8.9 |
| Electricity-Coal | 1920-2007 | 1.3 | 5.7 | 4.5 |
| Electricity-Oil | 1920-2007 | 1.5 | 6.2 | 4.2 |
| Electricity-Nat Gas | 1920-2007 | 1.8 | 9.6 | 5.5 |
| Freight Rail Travel | 1960-2006 | 2.0 | 2.5 | 1.2 |
| Air Passenger Travel | 1960-2007 | 1.3 | 6.3 | 4.9 |
| Motor Vehicle Travel | 1940-2006 | 0.3 | 3.8 | 11.0 |
Our consumption of goods and services creates a viable economy, and also reflects our social needs. For example, most of us consider it a social good that we can travel large distances rather quickly, safely, and more or less whenever we feel the need. Similarly, we realize social value in having aluminum (lightweight, strong, and ductile) available, in spite of its energy costs, because it makes so many conveniences, from air travel to beverage cans, possible. This is at the center of the sustainability paradigm: human behavior is a social and ethical phenomenon, not a technological one. Whether or not we must “overconsume” to realize social benefits is at the core of sustainable solutions to problems.
Resources
For more information about eco-efficiency, see the World Business Council for Sustainable Development report titled "Eco-Efficiency: Creating more value with less impact"
References
Dahmus, J. B., and T. G. Gutowski (2011) “Can Efficiency Improvements Reduce Resource Consumption? A Historical Analysis of Ten Activities” Journal of Industrial Ecology (accepted for publication).
1.5. Challenges for Sustainability*
The concept of sustainability has engendered broad support from almost all quarters. In a relatively succinct way it expresses the basis upon which human existence and the quality of human life depend: responsible behavior directed toward the wise and efficient use of natural and human resources. Such a broad concept invites a complex set of meanings that can be used to support divergent courses of action. Even within the Brundtland Report a dichotomy exists: alarm over environmental degradation that typically results from economic growth, yet seeing economic growth as the main pathway for alleviating wealth disparities.
The three main elements of the sustainability paradigm are usually thought of as equally important, and within which tradeoffs are possible as courses of action are charted. For example, in some instances it may be deemed necessary to degrade a particular ecosystem in order to facilitate commerce, or food production, or housing. In reality, however, the extent to which tradeoffs can be made before irreversible damage results is not always known, and in any case there are definite limits on how much substitution among the three elements is wise (to date, humans have treated economic development as the dominant one of the three). This has led to the notion of strong sustainability, where tradeoffs among natural, human, and social capital are not allowed or are very restricted, and weak sustainability, where tradeoffs are unrestricted or have few limits. Whether or not one follows the strong or weak form of sustainability, it is important to understand that while economic and social systems are human creations, the environment is not. Rather, a functioning environment underpins both society and the economy.
This inevitably leads to the problem of metrics: what should be measured and how should the values obtained be interpreted, in light of the broad goals of the sustainability paradigm? The Chapter Problem-Solving, Metrics, and Tools for Sustainability addresses this in detail, but presented here is a brief summary of the findings of the Millennium Ecosystem Assessment (MEA), a project undertaken by over a thousand internationally recognized experts, from 2001-2005, who assessed the state of the world’s major ecosystems and the consequences for humans as a result of human-induced changes. In its simplest form, a system is a collection of parts that function together. The MEA presents findings as assessments of ecosystems and ecosystem services: provisioning services such as food and water; regulating services such as flood control, drought, and disease; supporting services such as soil formation and nutrient cycling; and cultural services such as recreational, spiritual, religious and other nonmaterial benefits. MEA presents three overarching conclusions:
Approximately 60% (15 out of 24) of the ecosystem services examined are being degraded or used unsustainably, including fresh water, capture fisheries, air and water purification, and the regulation of regional and local climate, natural hazards, and pests. The full costs of the loss and degradation of these ecosystem services are difficult to measure, but the available evidence demonstrates that they are substantial and growing. Many ecosystem services have been degraded as a consequence of actions taken to increase the supply of other services, such as food. These trade-offs often shift the costs of degradation from one group of people to another or defer costs to future generations.
There is established but incomplete evidence that changes being made are increasing the likelihood of nonlinear changes in ecosystems (including accelerating, abrupt, and potentially irreversible changes) that have important consequences for human well-being. Examples of such changes include disease emergence, abrupt alterations in water quality, the creation of “dead zones” in coastal waters, the collapse of fisheries, and shifts in regional climate.
The harmful effects of the degradation of ecosystem services are being borne disproportionately by the poor, are contributing to growing inequities and disparities across groups of people, and are sometimes the principal factor causing poverty and social conflict. This is not to say that ecosystem changes such as increased food production have not also helped to lift many people out of poverty or hunger, but these changes have harmed other individuals and communities, and their plight has been largely overlooked. In all regions, and particularly in sub-Saharan Africa, the condition and management of ecosystem services is a dominant factor influencing prospects for reducing poverty.
Organizations such as the World Commission on Environment and Development, the Millennium Ecosystem Assessment, and several others including the Intergovernmental Panel on Climate Change, the Organization for Economic Cooperation and Development, and the National Academy Report to Congress have all issued reports on various aspects of the state of society and the environment. The members of these groups are among the best experts available to assess the complex problems facing human society in the 21st century, and all have reached a similar conclusion: absent the enactment of new policies and practices that confront the global issues of economic disparities, environmental degradation, and social inequality, the future needs of humanity and the attainment of our aspirations and goals are not assured.
1.6. Chapter Review Questions*
What are the essential aspects of “sustainability” as defined in the Brundtland Report?
Define “strong” and “weak” sustainability and give examples of each.
State, in your own words, the meaning of the “IPAT” equation?
What is the “rebound” effect and how is it related to human patterns of consumption?
Glossary
- eco-efficiency
An approach that seeks to minimize environmental impacts by maximizing material and energy efficiencies of production.
- ecosystem services
The benefits humans receive from ecosystems
- ecosystems
Dynamic systems of human, plant, animal, and microorganism communities and the nonliving environment that interact as a functional unit
- Jevons paradox
The principle that as technological progress increases the efficiency of resource utilization, consumption of that resource will increase.
- overconsumption
A long-term result in which the increase in consumption is greater than the efficiency improvement
- strong sustainability
All forms of capital must be maintained intact independent of one another. The implicit assumption is that different forms of capital are mainly complementary; that is, all forms are generally necessary for any form to be of value. Produced capital used in harvesting and processing timber, for example, is of no value in the absence of stocks of timber to harvest. Only by maintaining both natural and produced capital stocks intact can non-declining income be assured.
- sustainable development
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
- weak sustainability
All forms of capital are more or less substitutes for one another; no regard has to be given to the composition of the stock of capital. Weak sustainability allows for the depletion or degradation of natural resources, so long as such depletion is offset by increases in the stocks of other forms of capital (for example, by investing royalties from depleting mineral reserves in factories).