It was written by Dechucka:
/snip the loon's confused view of chemistry, meteorology, etc...etc...etc/
Post by Dechucka
Having done a lot of caving in my time CO2 does not fill up all the
holes in the ground.
Caves with multiple entrances usually do ventilate well (like chimney),
so CO2 pooling is not an issue. Caves with single entrances, specially
the vertical ones can have some serious safety issues with high
concentration of CO2 in the lower reaches of the cave. (see for instance
Bungonia, Borenore and Wellington caves).
However the cause has nothing to do with some sort of sinking of the
atmospheric CO2 due to its molecular weight but rather the CO2 emission
in an enclosed space by plant life in and above the caves (tree roots for
instance), some rotting organic material washed into the cave and the
limestone itself under pressure. The CO2 concentration in such caves can
be directly related to the time of the year when the vegetation is
growing the fastest.
Ergo, review your summer caving plans for Bungania very carefully unless
you want to end up with a horrible headache, vomiting and worse during
and after the trip.
BTW the poster you are responding to have claimed not so long ago, just
before I've plonked him that he has invented some sort of perpetual
motion machine. That fact alone already speaks volumes about his crazy
Ördög, without any apologies !!!