Newsgroups: sci.environment,sci.chem
Subject: Re: Global Worries? See: http://www.giss.nasa.gov/Data/GISTEMP/
From: rparson@spot.Colorado.EDU (Robert Parson)
Date: 6 Jul 1997 21:28:59 GMT

In article <33BFE6A8.D82@ix.netcom.com>,
Uncle Al  <uncleal0@ix.netcom.com> wrote:
>Sam McClintock wrote:
>>
>> Uncle Al <uncleal@uvic.ca> wrote:
>> > Said natural fluctuations from Popocatepetl are also blasting
>> > cubic miles of dust, sulfuric acid mist, HCl, and CO2 into the
>> > stratosphere.  Go tell Vulcan about the Greenhouse Effect and
>> > the Ozone Hole.
>>
>> Another scientist wannabe trying to blame Cl in the stratosphere on
>> volcanos; just too bad that ALL research on the subject places CFCs as
>> the predominant source.  If mankind had made the same level of effort
>> on research that Uncle Al does, we'd still be in the stone age. :<)
>
>You are so right.  A megatonne of Cl injected directly into the
>stratosphere by NATURAL causes is without sin.

 Except that no volcano on which measurements have actually been
 made has injected anything remotely approaching a megaton of Cl
 into the stratosphere. Pinatubo, the largest eruption since Katmai
 1912 (and in terms of total stratospheric penetration the largest
 since Krakatau 1883), orders of magnitude more powerful than the
 current dustups in Mexico and the Caribbean, made no significant
 net contribution to stratospheric chlorine. See:

 W. Mankin, M. Coffey and A. Goldman, "Airborne observations of
 SO2, HCl, and O3 in the stratospheric plume of the Pinatubo volcano
 in July 1991", Geophys. Res. Lett. _19_, 179, 1992.

 L. Wallace and W. Livingston, "The effect of the Pinatubo cloud
 on hydrogen chloride and hydrogen fluoride", _Geophys. Res. Lett._
  _19_, 1209, 1992.

 Moreover, ice core analyses, which document volcanic eruptions
 very nicely by means of SO2 spikes, show no evidence of chlorine
 enhancement following major volcanic eruptions, not even for
 monsters like Tambora 1815. See:
 R. J. Delmas, _Reviews of Geophysics_ _30_, 1, 1992.

 There is no evidence whatsoever that volcanoes are an important source
 of stratospheric chlorine. In fact, there never was any direct evidence
 - 20 years ago there was some intelligent speculation, that is all,
 which turned out to be wrong when measurements were actually carried out.
 It's a dead hypothesis, abandoned even by the people who originally came
 up with it.

 ------
 Robert