# Could earth run out of O2? [closed]

Death in a closed environment due to lack of O2 is actually not that bad:

And as far as I know as we are cutting down our life saving woods and jungles less $O_2$ is being produced and more $CO_2$ is not converted back to $O_2$. Greenpeace and others tell us how bad this fact is.

But: If it continues like this, is it possible for humanity to extinct itself because we run out of $O_2$ and breath in too much $CO_2$?

Wouldn't it be much nicer than like burning to death if the $O_2$ would disappear?

• Too much CO2 causes the asphyxiation response in which we gasp for air. Death by CO2 is not pleasant at all, which is what oxygen breathing life on earth would experience if CO2 levels ever increased to such levels. However, if CO2 did ever get to such levels, we would probably have cooked to death long before then. – BillDOe Nov 13 '17 at 20:04