Sustainability: a definition
Sustainability, in a broad sense, is the capacity to endure. It can be defined as the ability of an ecosystem to maintain ecological processes, functions, biodiversity and productivity into the future. In ecology, the word describes how biological systems remain diverse and productive over time. For humans it is the potential for long-term maintenance of wellbeing, which in turn depends on the wellbeing of the natural world and the responsible use of natural resources.
For humans it is the potential for long-term maintenance of wellbeing, which in turn depends on the wellbeing of the natural world and the responsible use of natural resources.
There is now abundant scientific evidence that humanity is living unsustainably. Returning human use of natural resources to within sustainable limits will require a major collective effort. Since the 1980s, human sustainability has implied the integration of economic, social and environmental spheres to: “meet the needs of the present without compromising the ability of future generations to meet their own needs. 
Efforts to live more sustainably can take many forms from reorganizing living conditions, reappraising economic sectors (green building, sustainable agriculture), or work practices (sustainable architecture), using science to develop new technologies (green technologies, renewable energy), to adjustments in individual lifestyles.
 United Nations General Assembly (1987) Report of the World Commission on Environment and Development: Our Common Future.</em> Transmitted to the General Assembly as an Annex to document A/42/427 - Development and International Co-operation: Environment. Retrieved on: 2009-02-15.