Who defined sustainable development as "Development that meets the need of the present generation without compromising the ability of the future generation to meet their own needs"?

United Nations Conference on Environment and Development (UNCED)

Sustainable development is that development which allows all future generations to have a potential average quality of life that is at least as high as that which is being enjoyed by the current generation. 

The concept of sustainable development was emphasized by the United Nations Conference on Environment and Development (UNCED), which defined it as: ‘Development that meets the need of the present generation without compromising the ability of the future generation to meet their own needs’.