Sustainability is a characteristic of a process or state that can be maintained at a certain level indefinitely. For planet earth, it is thus the intent to provide the best outcomes for the human and natural environments both now and into the indefinite future. One of the most often-cited definitions of sustainability is the one created by the Brundtland Commission, led by the former Norwegian Prime Minister Gro Harlem Brundtland. The Commission defined sustainable development as development that "meets the needs of the present without compromising the ability of future generations to meet their own needs." Sustainability relates to the continuity of economic, social, institutional and environmental aspects of human society, as well as the non-human environment. Sustainability is one of the four Core Concepts behind the 2007 Universal Forum of Cultures.