Shrink and share: humanity's present and future Ecological Footprint.

Sustainability is the possibility of all people living rewarding lives within the means of nature. Despite ample recognition of the importance of achieving sustainable development, exemplified by the Rio Declaration of 1992 and the United Nations Millennium Development Goals, the global economy fails to meet the most fundamental minimum condition for sustainability--that human demand for ecosystem goods and services remains within the biosphere's total capacity. In 2002, humanity operated in a state of overshoot, demanding over 20% more biological capacity than the Earth's ecosystems could regenerate in that year.