# How does Dichlorofluoromethane get into the stratosphere?

I was wondering why FCKWs can destroy the ozone layer. It seems like these gases have a high molecular weight in comparison to $$\ce{N2}$$ or $$\ce{O2}$$. How can these gasses come up to the outer layer of our atmosphere? In particular, how long (on average) would it take to get to such an altitude (through the diffusion of such a particle)?

I mean, they are basically several times heavier than all the other components of our atmosphere combined. Hence, it shouldn't be very energetically stable for them to float on the outer layers of space on top of other lighter particles.

• The dominant factor in getting into the upper atmosphere is the atmospheric lifetime of the gas. The atmosphere is fairly well mixed (obviously so since heavy gases like carbon dioxide don't settle out). But compounds that undergo easy reactions don't survive long enough to get fully mixed. CCl2FH is one of those short lived ones unlike its fully halogenated cousins. So it won't be notable in the upper atmosphere, at least compared, for example, to CCl2F2. – matt_black Jan 8 at 14:02