Toxic Sky

"If the oxygen level in such an environment falls below 19.5% it is oxygen deficient, putting occupants of the confined space at risk of losing consciousness and death." What happens if the world's atmospheric levels of oxygen fall to 19.5% or lower?

blogcritics.org
/59phae

I’ve been thinking about this issue for some time and I know that if we are to survive the next “X” event could this be the undoing of us all.
How well will the nuclear shelters deal with this?
Hiding in a cave with supplies will not help either.
So what to do?
Where to hide?
How long before we have done this to ourselves without any catastrophe or outside influence.
What if massive earthquakes release trapped co2 and methane into the atmosphere?
Volcanoes erupt spewing forth sulphur and other toxic gasses.

NewScientist.com news service
/67xvs8
The air we breathe is 21% oxygen, 79% nitrogen and minor amounts of other gases
eskimo.com
/5fdhm8
Earth's atmosphere is approximately 78.1% nitrogen, 20.9% oxygen, .9% argon, .0367% carbon dioxide, and the balance is mostly water vapor.

um...then we would die. in short. i mean...i could go day to day worrying that I could die, but there's no point cuz its gonna happen anyways one day.

HA HA Mad Hatter, I was looking for some positives, but this does seem to be a real issue and survivalists out there would know that this is one of the many things that can make all their preparations’ for nothing.

We live in a very tiny band of atmosphere and this has changed before in Earth’s history and some small changes are being noticed at the moment.

That seems to be the problem... you can have all the supplies you need, but unless you have your own powersource, oxygen maker, and a complete isolation fro outside gasses, you are going to die, wether or not it is fast or a slooooow process... you will get tired, and fall asleep...