From: tobis@meteor.wisc.edu (Michael Tobis)
Newsgroups: sci.environment
Subject: Re: Steering Clinton onto the right track
Summary: Don't tell those who know more than you their business.
Keywords: hubris
Date: 18 Nov 92 19:37:48 GMT
Organization: University of Wisconsin, Meteorology and Space Science

In article <1992Nov18.145201.1606@gn.ecn.purdue.edu> dyrda@gn.ecn.purdue.edu (Richard Dyrda) writes:
>>In article <1ec3rtINNc33@gap.caltech.edu> carl@SOL1.GPS.CALTECH.EDU writes:
>>>In article <1992Nov17.215924.829@gn.ecn.purdue.edu>, dyrda@gn.ecn.purdue.edu (Richard Dyrda) writes:
>>> Volcanic eruptionsput out 1,000's upon 1,000's more ozone depleting
>>>chemicals than we humans have ever done. Since volcanoes have erupted
>>>for 1 billion years I think our ozone level is just fine.
>>
>>Volcanos put out lots of REACTIVE chloring compounds, along with sulfates. 
>>Mostly these go into the troposphere where most of them are removed before ever
>>having a chance to reach the stratosphere (occasionally are really large
>>volcanic eruption may inject some chemicals directly into the stratosphere). 
>>CFC's, on the other hand, are not  very reactive (that's one of their big
>>advantages for refrigeration and industrial applications).  They have a very
>>good chance of reaching the stratosphere before being scavenged.  Hence pound
>>for pound, they present a MUCH larger threat to the ozone than do volcanic
>>compounds.
> 
> Ok say that 0.01% of these chlorine agents reach the actual ozone.
>Now lets say its roughly 10,000,000,000 particles of chlorine (I'm
>no chemist what is the actual amount?) That is 100,000,000 particles
>that reach the ozone per eruption. Say on average there is one eruption
>every ten years (and going 1,000,000 years back) this is 
>10,000,000,000,000 particles in the ozone. While it may not get there 
>all that often they have been there a lot longer and in much larger
>quantities than CFC's (which are being phased out by 1996).

Um, what's a particle of chlorine? Surely you don't mean a molecule? That
would amount to about a nanogram. 

Anyway, you are obviously talking without knowing what you are talking
about. The point Carl made about the atmospheric lifetime of the particles
seems to have escaped you completely. The half-life of volcanic emission
atmospheric residence time is on the order of a year. So there's only about
a year's worth of volcanic emissions in the stratosphere on average.
By comparison, the half life of the anthropogenic compounds under consideration
is about a century. (In both cases, the product that is eventually flushed
out is HCl.)

Natural chlorine is predominantly oceanic in origin. Current startospheric
chlorine concentrations exceed 4 times the natural background and continue
to increase rapidly, even with declining emissions. This is because the
time for the lower atmosphere to mix with the stratosphere is about two
decades. Thus we can expect stratospheric chlorine concentrations to increase 
for some time to come.

> You don't have to be an aeronautical engineer to know how to fly! Use
>your common sense, Sun creates ozone. Where are the holes located, at
>the poles. Where is there no sun for 6 months, at the poles. It seems
>pretty reasonable to me.

Again, you show not the remotest knowledge of the subject. If you had gone so
far as to read the Scientific American article (January 1988) you would know
that the question isn't the amount of ozone in the Antarctic, but the
preciptious decline in that amount that began around 1970, not correlated
with any volcanic activity.

If you really knew your stuff, you would know that actually there is less
column ozone closer to the equator and this is monotonic up to latitude
+/- 70 degrees or so. You would also know that the depletion occurs in the
spring AFTER the sun comes out and solar energy is an essential feature
of chlorine catalyzed ozone destruction. 

> Everything isn't scientific, remember theoretically I can put my
>hand through a desk w/o touching it.

I hope this isn't the brand of theory they are teaching you at nuclear
engineering school. Just what theory is that, anyway?

Maybe you might try to have some idea what you are talking about before
sharing your wisdom with the net, especially if you insist on being so
smug and snide about it. 

mt

--

references: 
_Aeronomy of the Middle Atmosphere_, Brasseur & Solomon, Reidel Press 1985

"Progress Toward a Quantitative Understanding of Antarctic Ozone Depletion",
Susan Solomon, _Nature_ vol 347 pp 347 ff, Sept. 1990.