By this time next week, thousands of environmental enthusiasts will have descended upon the southwestern U.S., setting up camp for several days of networking, education and plenty of sustainable innovation. There will even be a few celebrities and a dash of music. To the uninitiated, it initially may sound like a second iteration of Burning Man for 2009, but for anyone in the green building realm, it’s the must-attend four-day bonanza known as Greenbuild International Conference and Expo.

Certainly, it’s an exciting time to be convening, what with issues including climate change, energy efficiency, and green building frequently appearing in the daily headlines, across the blogosphere, and throughout Twitter feeds. As noted in this month’s newsletter, just last week, billions of dollars in federal funds were awarded toward smart grid research and development (the largest group of funding to be awarded in a single day). The industry also was abuzz that same week about reports that green retrofits and renovations could become a $10-$15 billion market in just five years.

We need look no further than Greenbuild’s host city, Phoenix, for examples of sustainable design and construction in motion. To be honest, in the past when I thought of Phoenix, I thought of three S’s: sun, sand and sprawl. My perspective is changing to focus on another S: sustainability. For our upcoming November/December issue, arriving in mailboxes this week, posting online over the coming days at eco-structure.com, and also available on-site at the Phoenix Convention Center during Greenbuild, we took a look at green projects sprouting in the desert, ranging from state-of-the-art technological campuses to a hand-crafted site 40 years in the works. Among the most interesting to me, however, was a project that has yet to take any built form.

Earlier this year, Phoenix mayor Phil Gordon brought forth an idea called Green Phoenix in his state of the city report. The plan consists of 17 general points, but has one goal: To make Phoenix the greenest city in the country. Intrigued, I called up Dr. Robert Melnick, the executive dean of Arizona State University’s Global Institute of Sustainability and also the man tasked with turning the general, overarching plan into concrete, executable steps—certainly no small task. While we chatted about the plan and how it is progressing—the first effort under Green Phoenix is a program seeking to green a 10-mile corridor along the city’s light rail—our conversation (featured in our Perspectives column for November/December) left me with a larger question that’s been stuck in my head ever since. That is: What does it take to truly make a city green and is it really possible for one metropolis to be the greenest of them all? Is it possible to judge San Francisco against Portland, Ore. or New York City against Phoenix—all of whom are vying for the green crown—when their individual contexts are so unique?

I’m looking forward to discussing this question with my fellow 25,000 Greenbuild attendees this week. I also would like to encourage our digital fans to give us their feedback across our online spectrum, from commenting on our stories at eco-structure.com to posting on our Facebook page or tweeting over at Twitter (@ecostructure). What do you think? Is it possible for one city to be the greenest metropolis around?