Smog tends to localised where greenhouse gas emissions are of global significants.
As someone who lives in a place without smog my main concern and what should be the main concern to all people on the planet is the emissions of greenhouse gases and how it affects our climate.
If you live in a smoggy place at least you have the option to move somewhere else if its damaging your health (it is something that we should be tackling as well as AGW) where as we haven't found another planet to move too yet.
All this talk of how we label these issues is just a smoke screen to try to obscure to real issues.
The planet is warming quickly we have caused this by the massive release of carbon based gases previously stored in the ground coupled with the destruction of carbon sinks such as forrests (the amounts we are releasing even if we hadn't destroyed so much forrest we would still be in trouble).
Those in denial love to steer the conversation away from the real problem by talking sematics.
