I don’t care how green your city claims to be. Unless you follow São Paulo’s lead and ban outdoor advertising, you’ll never be green. Until I can walk down a street without having my eyes and ears constantly assaulted by product advertisements, you’re chalk full of noise pollution and no amount of greening is going to fix that.
To see my point, compare these images (from eduadoZ and katedubya) from ‘Clean City’ with the image of Las Vegas below (from eircell.ie). What looks cleaner to you?