How can city pollution be fought?

How can city pollution be fought? How can we identify the main parameters that lead the increase of pollution? And then, how can we reduce pollution if some economic issues are against the pollution preventing program we could imagine?
Thus, information and communication are two things we cannot forget and it is really an important part of any anti-pollution program.

First, I think that the transport sector is a major contributor to greenhouse gas and other emissions. So, I think that we should deal with that very issue to fight city pollution.
The ever-increasing demand for new and efficient trans...