There are different definitions for sustainable development. The probably most common definition is found in the Brundtland Commission Report 1987 with the title "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."

Sustainable development does not only cover environmental aspects but also many other fields like culture, health and social welfare. The global society of today needs to integrate these aspects in its work for creating a sustainable future.

Several different methods for measurement of sustainable development have been proposed. It is difficult to measure sustainable development, as it is not defined in detail what is meant by sustainable development. Besides, the concept of sustainable development will evolve with time.

For more information please have a look at:

http://iisd1.iisd.ca/ (general information)

http://www.unep.ch/earthw/indicat.htm (indicators)