Wow nice discussion... holy moly !
As for me, I do not understand the details of the question and yet... if you are
not convinced of the negative effects of toxic emissions, try to let the engine
of your car run in a closed garage. I would say that at least for you, at that
moment, there is some minor damage being felt. And then imagine the same
experience with billions of cars world-wide, with the garage being our planet.
Imagining this, although it might sound retarded, makes me feel a tatty wee bit
unconfortable about it all.
Carry on please.