From: norris@aquifer.geology.uiuc.edu (Chuck Norris)
Subject: green house versus global warming
Organization: University of Illinois at Urbana
Date: Thu, 30 Jul 1992 21:51:36 GMT
Keywords: greenhouse global warming CO2


A couple of stray thoughts or observations have occurred during the exchanges
recently about global warming vs green house effects vs science vs politics.

I have found it one of the most interesting and enlightening threads to grace
s.g.m. in months.  Since most of us ultimately feed at the public trough,
it's important to not only do good science but to understand there is
an entirely separate 'review' process that operates, and it measures
our results not just against science and logic but against (social,
political, economic) acceptability of the implication of those results.
I happen to think social responsibility accompanies societal funding,
and it is untenable to take an approach that says "Ah ha!  I can prove,
Johnny, that I knew ten minutes ago that that burner would be hot enough
to burn you hand.  But since I didn't know whether it would be 2nd or
3rd degree burns, I wasn't justified in projecting the results by warning
you."

Thanks, Nick.  You've offered a nice view of what we can expect.  And thanks,
Michael, for hanging tough!

In the for what its worth department, I'm with Tobis on the ENSO observation.
For one thing, it obscures the fact that the same phenomenon was identified and
named by two strongly divergent elements of society, and scientists stumbled
onto later.  Common experience and social awareness is a valid form of
observation, just less comfortable to many of us.


Enough philosophy.  Green house vs global (climatic) warming:

A couple of documentable observations:

Diurnal temperature range at Champaign IL has steadily decreased over the 100+
years of weather records.

Annual precipitation has increased steadily over the same period from just
over 33.5 inches (1889-98) to 42.3 (1979-88).

(Premise:  Diurnal temperature range is a surrogate for moisture content,
as may be precipitation.)

Daily mean temperatures climbed very steeply to ~1950, dropped at about the
same rate for 25 years (hence not as far), and since have climbed at an even
steeper rate.

When viewed in temperature/humidity space, the weather at Champaign IL is not
oscillating about a central position, but is clearly in transit between
two states.  The 'from' state we can presumably (partially) document with
history, the 'to' state ...?
Is there any reason (beyond its being easily conceptualized) that the impact
of the (irrefutable) green house effect need be felt solely or primarily as
temperature increase?  In attempting to 'find' the impact in temperature
values are we overlooking alternative signals?


On a related note, someone posted the observation that for now, in the
tropics, increased cloud cover seems to provide offsetting albedo to keep
temperatures relatively unchanged.  Then speculated that if that doesn't
remain the case, we could be in real trouble.

If the sulfur in coal and petroleum represents a balance of the atmospheric
gases at the time the organisms were buried, and if we are merrily returning
the carbon to the atmosphere while diligently removing the sulfur (to protect
the environment), are we not venturing into uncharted waters?  Even if the
increased H2O results in increased clouds, aren't we talking about duller
clouds, and therefore higher temperature?  Seems to me if we want to return to
Cretaceous or Pennsylvanian aged CO2 levels we'd better do our best to make
sure we're creating the total corresponding atmosphere.  At least we know it
sustained a (probably) livable environment.

[Let's not EVEN consider going back to Cambrian conditions, Nick.  There may
have been abundant and diverse life (but not I think vertebrates), but there
was damn little if any terrestrial life, animal or vegetable.  It apparently
was NOT a hospitable environment on land!]


Thanks for any feedback (grin) and comments are appreciated.


Chuck Norris
University of Illinois
Department of Geology
Urbana, Illinois  61801            norris@aquifer.geology.uiuc.edu