The notion of 'sustainability' emerged in The Ecologist's A Blueprint for Survival, in 1972. The quest to make modern civilization 'sustainable' inspired the UN's Stockholm Conference in 1972 and the 'global trusteeship' of subsequent international environmental treaties. 'Sustainability' is related to 'futurity', hence the Brundtland Commission in 1987 defined sustainable development as 'development which meets the needs of the present, without compromising the ability of future generations to meet their own needs'. 'Sustainability' animates 'the precautionary principle', affirmed by the European Union (EU) in 1990 in its Bergen Declaration on Sustainable Development, which requires ecological preservation in cases of scientific uncertainty where serious or irreversible damage is threatened. The Earth Summit in 1992 established 'sustainable development' as the most important policy of the 21st century. 'Sustainability' is at the heart of The Rio Declaration on Environment and Development and Agenda 21, accords signed at the Earth Summit that herald a new paradigm of society, economics and the environment. The EU's Fifth Environmental Action Programme (1993) pursues 'sustainability' in industry, energy, transport, agriculture and tourism. 'Sustainability' has also been endorsed by the Clinton Administration (1994). In the light of these events, 'sustainability' is now used widely in biology, economics, sociology, urban planning, ethics and other domains. It is regarded as tantamount to a new philosophy, in which principles of futurity, equity, global environmentalism and biodiversity must guide decision-making. Far from being a mere doctrine of development science, 'sustainability' has emerged as a universal methodology for evaluating whether human options will yield social and environmental vitality.