What would a good outcome from Rio+20 look like?

A genuine question, honest.  Triggered by today’s earnest plea urging world leaders to get their act together and agree something – anything – for the Rio+20 conference, now only three weeks away.  But aside from some vague commitments to Sustainable Development Goals – which could well backfire horribly, as lots of us have argued here at GD and elsewhere (though they could just work if allowed to evolve slowly - see here), how will we know if they manage it?

There’s obviously a long wish-list built up over the last six months or so – as well as Sustainable Development Goals, there’s changes to the global governance of climate issues, the UN Secretary Genera’s Energy For All initiative, and a host of proposals from NGOs and others.  But in the world of feasible options, and starting from where we are now, what is the concrete difference – in the form of actual content for the actual declaration – between success and failure at Rio+20?  Answers on a postcard, please…..