rising background levels of carbon dioxide, ventilation, and train crashes

People are so worried about carbon dioxide causing global warming -- but I seldom see anyone worrying about other consequences of rising levels of background carbon dioxide.

I personally have found that I'm very sensitive to carbon dioxide levels in crowded rooms like classrooms, theaters, hotel ball rooms, and commuter trains.  I get restless limbs, nausea, and drowsiness -- and even narcolepsy -- in these environments.

Carbon dioxide is heavier than air.  With the advent of air conditioning, it has become fashionable to have only ceiling ventilation in rooms.  Ceiling ventilation is not very good at removing carbon dioxide from the air.

In older rooms that have floor vents, I feel that the air is much clearer and I am much more alert.

I am particularly concerned about ventilation in trains.  I have often found that I get narcolepsy in trains.  I once complained of this and MetroNorth turned up the ventilation in the trains and I found that I stopped getting drowsy.

I noticed in college that I used to fall asleep a lot in a basement classroom.  It was only later that I realized that a basement classroom, being below ground level, would be very hard to clear of carbon dioxide.

There has been a recent spate of engineers falling asleep and causing train wrecks.  This has been blamed on undiagnosed sleep apnea.  But why would there suddenly be undiagnosed sleep apnea when there wasn't before?

I strongly suspect that sleep apnea is being wrongly blamed for these incidents. I strongly suspect that there is an unsafe level of carbon dioxide on these trains that is contributing to these incidents.

I am frustrated that I can't get anyone to pay attention to my concern about this