Sustainability is improving the quality of human life while living within the carrying capacity of the world's ecosystems.

Green Skills strive for a community in which all people share and experience the principles of biodiversity and ecological integrity; equity and human rights, long-term economic health and personal well being.

The most commonly quoted definition is from the Brundtland Report (1987): 

"Sustainable development is development that meets the needs of the present without compromising the needs of future generations to meet their own needs.  It contains within it two key concepts:

The concepts of needs, in particular the essential needs of the worlds poor, to which overriding priority should be given, and:

The idea of limitations imposed by the state of technology and social organization on the environments ability to meet present and future needs." 

Sustainability is sometimes described as the ‘triple bottom line’, to reflect the importance of environmental, social and economic factors in decision-making.  However, we need to integrate our actions across all three areas to achieve human and ecosystem wellbeing and happiness for all.

A selection of definitions on sustainability 

(from Sustainable Seattle http://www.ecy.wa.gov/sustainability/more_defns.htm)

Robert Gilman

Sustainability  is equity over time ... think of it as extending the Golden rule through time .. Do unto future generations as you would have them do unto you.

Paul Hawken

Leave  the world better than you found it, take no more than you need, try not to harm life or the environment, make amends if you do.

James  Coomer 

A  sustainable society is one that lives within  the self-perpetuating limits of its environment. That society is not a "no growth" society - it  is, rather a society that recognizes the limits of  growth and looks for alternative ways of growing.

Sustainable  Seattle 

Sustainability  is a new way of thinking about an age-old  concern: ensuring that our children and grandchildren  inherit a tomorrow that is at least as good as today,  preferably better. We want to make sure that the way  we live our lives is sustainable - that it can  continue and keep improving for a long, long time.

Barbara  Lither

If  you get right down to it, sustainability is  really the study of the interconnectedness of all  things.

James  McNeil

Growth  based on forms and processes of development  that do not undermine the integrity of the environment  on which they depend.

David  Schaller

Achieving  the ecological balance which allows economic  prosperity and social equity to be achieved across  generations.