"Fundamentally this program is about improving California," he said. "If you as a company trumpet yourself as sustainable when your performance is quite low, then it's up to the marketplace to call you out."
Read more: http://www.sfgate.com/cgi-bin/blogs/wine/detail?&entry_id=55249#ixzz0chG0qfLW
I think the approach used by winemakers - a big tent, fairly modest program for sustainability with the hint silver, gold and platinum certification levels – is the most pragmatic and time-sensitive approach to this issue. The soon fresh produce marketers get in place a credible sustainability certification – now matter how limited the "metrics" are to start with – the better off the idsutry will be.
FYI: Here is a report by Five Winds International – the consulting company that helped created the wine standard – about retailers and sustainability.