"Sustainability"

By Robert Gilman
from the 1992 UIA/AIA "Call for Sustainable Community Solutions"

What is "sustainability," and why is it generating so much interest? In its broadest scope, sustainability refers to the ability of a society, ecosystem, or any such on-going system to continue functioning into the indefinite future without being forced into decline through the exhaustion or overloading of key resources on which that system depends.

In the case of society, those resources might be material, such as fuels or topsoil; they might be social, such as educational levels or the sense of fair play; or they might be waste-absorbing natural systems, such as wetlands or the atmosphere.

Given this definition, it is not surprising that there are grave concerns about the sustainability of today's human societies. Consider just two examples from a long a growing list of concerns:

• World per capita grain production has been in decline since the mid 1980s due to soil degradation and the loss of farmland, and shows every sign of declining still further in the coming decades. The world fish catch shows a similar pattern as fisheries around the world are over-fished and exhausted. Yet world population, and thus the need for more food, continues to grow.
  
• Industrial society is overwhelmingly dependent on fossil fuels, and continues to build its physical plant as if these fuels will be cheaply available forever, in spite of the fact that world oil discoveries peaked in 1962, and every year damage from acid rain and concern about CO2-produced global warming grow greater.

More generally, we are using nonrenewable resources as if they were in infinite supply, we are pouring wastes into the environment as if they could be infinitely absorbed, we are harvesting renewable resources faster than they can be replenished, and we are allowing our numbers to grow as if there will always be "more" - more land, more food, more everything. Our society has not yet comprehended that the world is indeed round. If we persist in this ignorance, business-as-usual will lead humanity (and millions of other species) to a very grim future in the coming decades.

Fortunately, business-as-usual is not the only path open to us. Many specialists in the area of sustainable development are convinced that humanity could have a bright future if the whole world:

• made use of currently proven technologies and techniques 1) to greatly improve the efficiency of our resource use, 2) to greatly reduce our waste-stream going into the environment, and 3) to maintain and conserve renewable resource systems, like topsoil, fisheries, forests, and water supplies
  
• stabilized the human population through such proven techniques as the broad availability of birth control means and enhanced quality of life for women and families
  
• stabilized overall consumption of resources through switching, especially in industrialized countries, to a focus on "better" and "enough" (quality) rather than "more" (quantity).

All three of these steps are within our human capability. Our future depends on whether we take them.

If we do succeed in developing a sustainable society, it is likely that it will have the following characteristics:

• All material processes will be designed to be cyclical. There will be no such thing as waste or pollution, only outputs from one system serving as assimilatable inputs to another.
  
• The driving physical energy used by society will be renewable solar energy, either directly or in forms such as wind, hydropower, and biomass.
  
• The human population and the quantity of material goods will be stable in size (or gradually declining). This does not imply a static society, for changes in quality can continue unabated; indeed they may accelerate.