Before we get to the goodish news, a caveat: Let's not for any reason allow this kind of thing to make us feel like we can run the A/C all summer and crank the heat with the windows open. Now onto the results. A new study by the International Institute for Environment and Development in London shows that "greenhouse gas emissions for New Yorkers are less than a third of those of the national average for the USA. Those of Barcelona residents are half the average for Spain." In fact, all 11 cities surveyed fared better than their rural counterparts.Not too shabby, but let's think about this. If we're talking per person emissions, this makes perfect sense, especially if you've ever been inside a New York City apartment. Also, city dwellers drive less, and tend to be home less, also curbing energy use.Says the IIED's David Dodman: "Many cities have surprisingly low per capita emissions but what is clear is that most emissions come from the world's wealthier nations. The real climate-change culprits are not the cities themselves but the high consumption lifestyles of people living across these wealthy countries."He also added that most people living in cities still produce more than their per capita emissions allowance, with the exception of Sao Paulo and Rio.It's not the first study of its kind (Brookings did one last year-the link seems to be dead though), and I wonder what the takeaway is from this kind of report. Because like we said, we needn't be patting ourselves on the back quite yet.