Well, using a movie as an example of a phenomena might seem lame to you, but since we don't have any historical video evidence to show what could happen, it's all we've got.
I suppose you also think that "life after people" is lame too?
Anyhow, there is also concrete evidence that what we're doing is accelerating the process and in fact, the smog and airborne particulate is actually slowing the warming process from the sun.
Anyone with an I Q over 75 realizes that by cutting down all the mechanisms for cleaning our air, and introducing 10 fold more pollutants can't be a good thing. Or are you going to try and tell me the brown haze of smog over every city is a natural occurance?
I tell you what primo, we'll do a little experiment shall we? We'll go to home depot, buy 50 house plants and put them in your garage with a lawn chair. We'll close the door and have you sit in that lawnchair for an hour. We'll test your heartrate.
Then we'll pull out all the plants and put in a smart car. We'll start the smart car, close the door and have you sit in the lawnchair for an hour. We'll then test your heart rate (if you have one).
I'm free this saturday so you can prove your point that what we're doing has no effect on our environment.