We are what we measure.   It's time to measure what we want to be.

Definitions of sustainability and sustainable development

Webster's New International Dictionary
"Sustain - to cause to continue (as in existence or a certain state, or in force or intensity); to keep up, especially without interruption diminution, flagging, etc.; to prolong."
Webster's New International Dictionary. (Springfield, Mass.: Merriam-Webster Inc., 1986)
 
Caring for the Earth
"improving the quality of human life while living within the carrying capacity of supporting eco-systems."
IUCN/UNEP/WWF. Caring for the Earth: A Strategy for Sustainable Living. (Gland, Switzerland: 1991).(IUCN - The World Conservation Union, UNEP - United Nations Environment Programme, WWF - World Wide Fund for Nature).
 
Sustainable Seattle
Sustainability is the "long-term, cultural, economic and environmental health and vitality" with emphasis on long-term, "together with the importance of linking our social, financial, and environmental well-being"
http://sustainableseattle.org/
 
Friends of the Earth Scotland
"Sustainability encompasses the simple principle of taking from the earth only what it can provide indefinitely, thus leaving future generations no less than we have access to ourselves."
http://www.foe-scotland.org.uk/
 
Thomas Jefferson Sustainability Council
"Sustainability may be described as our responsibility to proceed in a way that will sustain life that will allow our children, grandchildren and great-grandchildren to live comfortably in a friendly, clean, and healthy world . that people:
  • Take responsibility for life in all its forms as well as respect human work and aspirations;
  • Respect individual rights and community responsibilities;
  • Recognize social, environmental, economic, and political systems to be inter-dependent;
  • Weigh costs and benefits of decisions fully, including long-term costs and benefits to future generations;
  • Acknowledge that resources are finite and that there are limits to growth;
  • Assume control of their destinies;
  • Recognize that our ability to see the needs of the future is limited, and any attempt to define sustainability should remain as open and flexible as possible."

http://www.tjpdc.org/
 

The Natural Step Four System Conditions
Substances from the Earth's crust must not systematically increase in nature. (This means that fossil fuels, metals, and other minerals can not be extracted at a faster rate than their re-deposit back into the Earth's crust).
Substances produced by society must not systematically increase in nature. (This means that things like plastics, ozone-depleting chemicals, carbon dioxide, waste materials, etc must not be produced at a faster rate than they can be broken down in nature. This requires a greatly decreased production of naturally occurring substances that are systematically accumulating beyond natural levels, and a phase-out of persistent human-made substances not found in nature.) 
The physical basis for productivity and diversity of nature must not be systematically diminished. (This means that we cannot harvest or manipulate ecosystems in such a way as to diminish their productive capacity, or threaten the natural diversity of life forms (biodiversity). This requires that we critically examine how we harvest renewable resources, and adjust our consumption and land-use practices to fall well within the regenerative capacities of ecosystems.) 
We must be fair and efficient in meeting basic human needs. (This means that basic human needs must be met with the most resource-efficient methods possible, including a just resource distribution.)
Adapted from http://www.naturalstep.org/
 
Jerry Sturmer
Santa Barbara South Coast Community Indicators
Sustainability is meeting the needs of all humans, being able to do so on a finite planet for generations to come while ensuring some degree of openness and flexibility to adapt to changing circumstances.
JSturmer@aol.com
 
Random House Dictionary of the English Language
"Develop - v.t. - to bring out the capabilities or possibilities of, to bring to a more advanced or effective state"
Random House Dictionary of the English Language. (New York, NY: Random House: 1987).
 
Our Common Future
"Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs."
Page 8, World Commission on Environment and Development. Our Common Future. (Oxford, Great Britain: Oxford University Press, 1987). (Frequently referred to as the Brundtland report after Gro Harlem Brundtland, Chairman of the Commission)
 
Hamilton Wentworth Regional Council
"Sustainable Development is positive change which does not undermine the environmental or social systems on which we depend. It requires a coordinated approach to planning and policy making that involves public participation. Its success depends on widespread understanding of the critical relationship between people and their environment and the will to make necessary changes."
http://www.unesco.org/most/usa4.htm
 
World Business Council on Sustainable Development
"Sustainable development involves the simultaneous pursuit of economic prosperity, environmental quality and social equity. Companies aiming for sustainability need to perform not against a single, financial bottom line but against the triple bottom line."
  "Over time, human and social values change. Concepts that once seemed extraordinary (e.g. emancipating slaves, enfranchising women) are now taken for granted. New concepts (e.g. responsible consumerism, environmental justice, intra- and inter-generational equity) are now coming up the curve."
http://www.wbcsd.org/
 
Interfaith Center on Corporate Responsibility (ICCR)
"Sustainable development...[is] the process of building equitable, productive and participatory structures to increase the economic empowerment of communities and their surrounding regions.
Interfaith Center on Corporate Responsibility, 475 Riverside Drive, New York, NY 10115, 212-870-2295