It won't spoil anything in case you haven't seen the movie, but I gained a lot more respect for Tom Cruise demanding to do all his own stunts in Ghost Protocol.
I'd actually be more scared of coming down than going up!
I bet their eyes and lungs were burning from all that smog. Maybe the smog level was below them though. Either way, there's NO way I would trust Chinese construction at a level like that, even on a good day.