The United Nations Conference on Sustainable Development, a.k.a. Rio +20 Summit, kicks off this week and, along with population growth, urbanism is expected to be a main topic of study and conversation.

The event is massive and complex. Aside from the main event — a meeting of heads of state that will span June 20 to 22 and likely include marathon talks in an effort to scratch out actionable international agreements — there are more than 500 side events taking place in Rio.

In his Monday morning email to readers, GreenBiz.com executive editor Joel Makower wrote:

Jay Carson, executive director of C40, the sustainable cities initiative started by Michael Bloomberg and Bill Clinton, told me by phone from Rio over the weekend: “The vast majority of the conversation here is around cities” — a big change from two years ago in Copenhagen, when cities were barely on the agenda.

Building better cities, in fact, is the topic of a presentation Makower will give during the World Green Summit, an event sponsored by Phillips and a number of other blue chip firms.  Rest