New ways to rank 'green' cities

New York City's ban on smoking in parks gets high green marks. But what about other criteria?

I'm always looking for new ways to track city quality of life. This article from the NY Post talks about the recent reduction in smoking rates in NYC. That's a good new indicator. Two more indicators that I'm having trouble collecting data on are dog poop and public spitting. Rome would not score high on the doggy criteria. Some of China's cities wouldn't score great on the spitting.

As usual, an index weights issue would arise. If a city has lots of smokers but no spitting or dog poop --- is it "green"?

For those researchers looking for an applied micro topic, it would interest me if a good paper can be written on the effects of exposure to 2nd hand smoke using the within city declines in smoking rates to generate some cross city variation. I realize that exposure and effects are not instantaneous. In the smoking externality literature, the effect of second hand smoke has been an important factor in determining what is the optimal smoking tax. I don't believe we know this effect?