<http://schema.org/about>
"Gil Friend (see his bio here) writes on WorldChanging: \"I think we're likely to look back on 2005 as the tipping point for 'sustainability.'\" For those that are not familiar with the \"tipping point\" concept (\"The phrase tipping point refers to that"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/culture/2005-has-sustainability-reached-the-tipping-point.html>