What is "sustainability"?

What after all does it mean to sustain something?  Does it mean to maintain planetary and human healthfulness in perpetuity?  If so – what is the baseline?  What standard might we use for what we want to ‘maintain?’

I know – not good practice to answer questions with questions – but I think it’s important to think deeply about this on an individual basis before we can apply it to local issues or the global systems and anything in between.

The United Nations Commission on Sustainable Development defined sustainability in the 1983 Brundtland Report. The report defined sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs."

I’ve underlined these sections to point out that needs change from person to person, and that we likely have no clue as to exactly what future generations will “need.” And heaven forbid… What if people of the future – our grandchildren for example - want to have more than their ”needs” met?
 
I actually prefer to think of sustainability as Hans Carl von Carlowitz thought of it. As the "father of sustainable yield forestry" and the first recorded European to define sustainability, Hans published “Sylvicultura Oeconomica,” which loosely translates to the economics and instructions for the growth of wild trees (Wilderer, Schroeder, and Kopp, 2005).  The root (pun intended) of the word then is at the intersection of economic and ecologic equilibrium.  Achieving this balance is difficult but undoubtedly has societal benefits. Since Von Carlowitz’s time the term has come to mean finding harmony in economy, ecology, and equality. Some people say these three E’s make up the triple bottom line – others use the terms "people," "planet," "prosperity."

 I am not sure these ambiguous terms help define an already ambiguous term.  Maybe that is the beauty and eternal struggle of sustainability… Maybe in this way sustainability rises to simplicity through complexity and to thoughtfulness through connectivity…

How do you define sustainability?