"Meeting the needs of the present without compromising the ability of future generations to meet their own needs."

Or, some might say: "Living life on earth in a way in which our children, grand children and all future generations can enjoy the same quality of life as we do..."

  • What do you think would be a good definition?

Sustainability depends on the amount of people or animals living in a certain area, the limits of nature (only so many people can eat the fruits of one tree!), and availability of natural resources (such as wood to burn for fire). Sustainability is achieved by giving current, future and future future people the same access to the resources they need without loss of environmental quality.

Technological Sustainability
Most sustainable development today addresses immediate needs to expand employment opportunities, improve energy efficiency, and increase the availability of food and water. These strategies rely heavily on the development and use of new technologies. These technologies must expand economic activities, address environmental impacts, improve social conditions and maintain or increase living standards.

Economist refer to technological sustainability as "weak sustainability." From an economic perspective, weak sustainability is achieved by maintaining total capital stocks. Capital stocks are services and goods that satisfy human needs and wants. They include man-made capital stocks (machines and buildings), human-capital stocks (skills and knowledge), and natural-capital stocks (like ecosystems and natural resources). Advocates of weak sustainability believe these stocks are equally valuable and that one stock may be substituted for another that is depleted or in short supply.

Because a technological approach to sustainable development depends on technological innovations, the decision makers in this process are scientists, economists, corporate leaders, governments, and scientific and financial institutions. Thus, technological sustainability strategies do not require individuals to adopt new or different views about the relationship between people and the environment. Therefore, programs implemented to promote technological sustainability likely will not foster long-term changes in human behavior. They will force people to behave differently, but do not teach people the reason why. When the technologies are removed, people may revert to past resource-use practices.

Ecological Sustainability
Ecological sustainability relies on advanced ecological literacy and environmental protection. Ecological sustainability requires stable and reduced levels of population growth and natural resource use (in contrast to economic growth assumption made for technological sustainability). Goal is to bring the scale of human activities within environmental limits.

With populations living within their ecological carrying capacities, natural systems could provide a template for economic development. Wastes from one business would become the raw materials for another. Natural resources would be used at renewable rates, and the environment's natural water- and air cleansing abilities would not be exceeded. This would be a shift from our current growth-focused economy, which rapidly is depleting nonrenewable resources, damaging biological diversity, changing the composition of gases in our atmosphere, and altering natural pace of evolutionary processes.

Ecological economists refer to ecological sustainability as "strong sustainability" because it places the highest value on natural-capital stocks: the services and resources provided by natural ecosystems. Advocates of strong sustainability do not believe human ingenuity or man-made capital stocks like commercial forests or aquaculture can provide long term substitutes for the resource-generating and pollution-cleansing services of natural systems.

The ability of individuals and communities to distinguish needs from wants and to change their behavior is fundamental to achieving ecological sustainability. So is the ability to identify needed services and the different methods for providing them. In the case of transportation, people often confuse the needed service--easy access to jobs and shopping--with one method for providing the services--more roads. Access may be provided better through improved public transportation or changes in local zoning that offer shopping and other services within easy walking distance, Ecological sustainability does not intend to promote hardship. Instead, it seeks to provide needed resources and services by using an efficient mix of advanced and traditional technologies to achieve a high level of human comfort.

Education about Sustainability
Education about sustainability differs from traditional environmental education in several ways. First, education for sustainability shifts the emphasis from simply solving existing environmental problems to preventing them in the future. Second, it demands future generations' needs to be considered in current decision making and values the role of non-human life forms in natural ecosystems. At a time when technological sustainability is needed to quickly address the global development crisis, education for ecological sustainability is a critical investment in the future.

In responding to unanticipated ecological, social and economic crises, proponents of technological sustainability place their faith in the ability of undiscovered or emerging technologies to solve problems associated with food stocks, energy reserves, safe water availability, job opportunities and social unrest. Plans to promote ecological sustainability seek to minimize these crises proactively and expand the natural resource use option of future generations. These plans call for cautious environmental and natural resource-use decisions that minimize risk and provide ample reserves for emergency use--the ultimate test of sustainability.

Adapted from "Coming To Terms With Sustainability," Environments For Life, Conservation Issues Forum Series. Izaak Walton League of America, Sustainable Education Project, March 1997.