The essence of the term sustainable is "that which can be maintained over time." By implication, this means that any society that is unsustainable cannot be maintained for long and will cease to function at some point.
Unfortunately, in recent years the word sustainable has become widely used to refer merely to practices that are reputed to be more environmentally sound than others. Often the word is used so carelessly as to lead some environmentalists to advise abandoning its use.
Nevertheless, the concept is indispensable and should be the cornerstone for all long-range planning. It is probably safe to assume that no human living arrangement can be maintained forever. Astronomers assure us that in several billion years the Sun will have heated to the point that Earth’s oceans will boil away. Thus sustainability is a relative term. It seems reasonable to use as a frame of reference for the durations of prior civilizations, ranging from hundreds to thousands of years. A sustainable society, then, would be able to maintain itself for many centuries at least.
How Do We Define Sustainability?
The concept of sustainability has been embodied in the traditions of many indigenous peoples; for example, it was a precept of the Iroquois Confederacy’s Gayanashagowa or Great Law of Peace, that chiefs consider the impact of their decisions on the seventh generation to come.
The first known European use of the word sustainability (German: Nachhaltigkeit) occurred in 1713 in the book Sylvicultura Oeconomica by German forester and scientist Hans Carl von Carlowitz. Later, French and English foresters adopted the practice of planting trees as a path to "sustained-yield forestry."
The term gained widespread usage after 1987, when the Brundtland Report from the United Nations’ World Commission on Environment and Development defined sustainable development as development that "meets the needs of the present generation without compromising the ability of future generations to meet their own needs." This definition of sustainability has proved extremely influential and is still widely used; nevertheless, it has been criticized for its failure to explicitly note the unsustainability of the use of nonrenewable resources and for its general disregard of the problem of population growth.
Also in the 1980s, Swedish oncologist Dr. Karl-Henrik Robèrt brought together leading scientists to develop a consensus on requirements for a sustainable society. In 1989 Robèrt formulated this consensus in four system conditions for sustainability, which in turn became the basis for an organization, the Natural Step. Subsequently, many businesses and municipalities around the world pledged to abide by Natural Step conditions.
The four conditions are as follows:
In a sustainable society, nature is not subject to systematically increasing:
1. concentrations of substances extracted from the earth’s crust.
2. concentrations of substances produced by society.
3. degradation by physical means.
And, in that society:
4. people are not subject to conditions that systematically undermine their capacity to meet their needs.
Seeing the need for an accounting or indicator scheme by which to measure sustainability, Canadian ecologist William Rees and graduate student (at the time) Mathis Wackernagel developed in the early 1990s the concept of the "ecological footprint," defined as the amount of land and water area a human population would hypothetically need to provide the resources required to support itself and to absorb its wastes, given prevailing technology.
Implicit in the scheme is the recognition that, for humanity to achieve sustainability, the total world population’s footprint must be less than the total land and water area of Earth (that footprint is currently calculated by the Global Footprint Network as being about 40 percent larger than the planet can regenerate, indicating that humankind is to this extent overconsuming resources and operating in an unsustainable manner).
A truly comprehensive historical survey of the usage of the terms sustainable and sustainability is not feasible. A search of Amazon.com for sustainability April 1,2010) yielded 8,875 book titles containing the word. A search of journal articles on Google Scholar turned up 108,000 hits, indicating many thousands of scholarly articles with the word sustainability in their titles. However, a perusal of the literature suggests that most of this immense body of work repeats, or is based on,the definitions and conditions described above.
Five Axioms of Sustainability
As a contribution to this ongoing refinement of the concept, I recently formulated five axioms (self-evident truths) of sustainability.
My goal was simply to distill ideas that had been proposed previously and put them into a concise, easy-to-understand form. In formulating these axioms, my criteria were as follows:
•To qualify as an axiom, a statement must be capable of being tested using the methodology of science.
•Collectively, a set of axioms intended to define sustainability must be minimal (with no redundancies).
•At the same time, the axioms must be sufficient, leaving no glaring loopholes.
•The axioms should be worded in terms a lay person can understand…