Define Sustainability?  Here are a few examples:

1. UBC “a societal conversation about the kind of world we want to live in, informed by some understanding of the ecological, social and economic consequences of our individual and collective actions”

2. BioScience  (Vol. 60 No. 7 p539) “meeting human needs in a socially just manner without depriving ecosystems of their health”

3. SCIE 120 (UBC) “the ability of humans to coexist and ensure that our creative capacities for enterprise and discovery do not extend beyond the limits of the supporting ecosystems on which we depend”

4. Brundtland Commission (World Commission on Environment and Development) “development which meets the needs of current generations without compromising the ability of future generations to meet their own needs”.

The core of the problem with nailing down a concrete definition is that it has different meaning to us as individuals, discipline groups, and contexts.  If we recognize our common goal of leaving the world in better shape than it is now, we can move beyond debate and work toward finding solutions.