Here at Earth to Philly we've tweaked Mayor Nutter for his oft-repeated declaration that by the end of his second term (let's not pretend we don't know he'll get one) Philadelphia will be "The Greenest City in America." At the United Nations Environment Program on Sustainable Building Practices last week he indicated that the goal may indeed be more of a rhetorical device than a competitive race to number one. Is that a bad thing?

The Symposium on Sustainable Buildings was held Thursday and Friday at the T.C. Chan Center for Building Simulation and Energy Studies at the University of Pennsylvania. Our mayor was joined by other mayors and leaders at an event "to learn more about the mutual global effort to make where we live and work more comfortable and efficient." The T.C. Chan Center has a track record of working with institutions around the world both governmental and non- to create more sustainable buildings, largely by consultation and the development of simulation tools.

Dr. Ali Malkawi, the founder of TC Chan, discussed the center's work in building and retrofitting commercial and multi-family residential buildings around the Philadelphia area "not only to increase the efficiency of the area's buildings, but also to stimulate investment and quality job creation across the region."

Mayor Nutter rightly crowed about the sustainability programs he has initiated here (some of which he had pushed for back in his Councilman days) and observed that "I can honestly say that I'm saving money, putting people to work and delivering a high quality of service at a very low cost." Perhaps a bit ruefully, he added, though, that "What they want is no cost."

The symposium, however, was about real-world scenarios balancing costs, both direct and externalized, with payoffs in efficiency, usability and sustainability. And to this end, Nutter seemed to recast his "Greenest City in America" pledge as part of a group effort: "I want to encourage all of my fellow mayors in the United States and around the world: everyone should set a goal to be the number one green city. If we strive for this goal, everyone will win."

Wait, I thought it was all about being number one? Nutter addressed this. "It's not about being number one. It's about doing what's right for our city."

No one can claim Nuter has been anything but Philadelphia's greenest mayor, so it's hard to second-guess his strategy. With the news today from the Inquirer that Swarthmore won third place in a contest sponsoered by the Environmental Protection Agency to achieve the highest percentage of building power from renewable energy, and the various ways the borough finagled and innovated to get there, the value of competing in this arena is palpable. Even Swarthmore's leaders still say they're going for number one.

Obviously not all of Swarthmore's methods are scalable to a metropolis like Philadelphia, but it's worth noting that we've got momentum toward a greener economy and greener living here in Southeastern Pennsylvania. Sharing the knowledge, as well as the motivation, at networked events such as that at the TC Chan center can only help to raise the bar higher.