Several years ago, I remember hearing about a big out-bubbling of carbon dioxide from a lake (in Aftrica?). This carbon dioxide, being heavier than air “pooled” in the low lying areas and killed a lot of animals and people.
Which got me thinking – always a dangerous proposition.
If carbon dioxide is heavier than air (which it is), why doesn’t it all settle to the ground? What mechanism keeps it suspended or mixed in the atmosphere?
My first thought was “wind”, but there are lots of windless days. And why wouldn’t wind encourage the CO2 to settle out, kind of like shaking a bowl of popcorn (which allows the heavier unpopped kernels to fall to the bottom)?
Also, do the ratios of elements in the air significantly change as a function of altitude? E.g., are there significantly fewer “heavier than air” atoms in the upper atmosphere?
Help me fight my ignorance. Why does carbon dioxide stay mixed in the atmosphere?