How long does it take?

This is one generation later than I first came across the idea at school in 1975. And it still only includes environmental agencies. An ecosystems approach without economic and social agencies? How long until the whole picture is seen and understood, before we see the world in its full and glorious interdependence, and before we are able to say with any confidence that we will not destroy ourselves?

http://www.defra.gov.uk/wildlife-countryside/natres/eco-actionp.htm