Xref: utzoo sci.bio:4040 sci.environment:8810
Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!ncar!bierstadt.scd.ucar.edu!ilana
From: ilana@bierstadt.scd.ucar.edu (Ilana Stern)
Newsgroups: sci.bio,sci.environment
Subject: Re: Coral reefs and global warming
Message-ID: <9351@ncar.ucar.edu>
Date: 30 Nov 90 17:31:59 GMT
References: <719@sierra.stanford.edu> <1990Nov30.141515.26084@ncsuvx.ncsu.edu> <BBC.90Nov30103535@sicilia.rice.edu>
Sender: news@ncar.ucar.edu
Distribution: na
Organization: Scientific Computing Division/NCAR, Boulder, CO
Lines: 58


(This no longer has much to do with coral reefs, and thus sci.aquaria/bio,
but I couldn't let this by.)

In article <1990Nov30.141515.26084@ncsuvx.ncsu.edu> kwf@ecersg.ncsu.edu 
(Ken Fernald) writes:
>
>You may also want to consider the possibility that global warming
>exists only in certain crude computer models that have been
>extrapolated far beyond reasonable limits.  There is actually little
>scientific data which supports global warming, and in fact, global
>temperature measurements show that the warming simply isn't happening.

1) The computer models are not crude (I've worked with them, I know!)
unless your definition of crude is "something that falls short of being
a perfect model in any respect."  Models today include such variables
as heat fluxes into and out of the surface, soil temperature and moisture,
ocean currents, clouds (which are no longer "white boxes" but include
some microphysics), and rain and snowfall.  

2) "Extrapolated far beyond reasonable limits" is handwaving.  What is
a reasonable limit, to you?  Considering the chaotic nature of the
atmosphere, in a sense anything beyond 10-14 days is unreasonable as
an exact forecast.  BUT we are not trying to forecast the temperature
on July 25th, 2010.  Hundreds of runs are made, "spinning up" the
climate until it reaches a steady state, and the average of the results
is what is considered.  

3) There is a great deal of scientific data which supports global warming.
It does not support it unequivocably.  The observed warming (0.3-0.6C/100
years, with the five warmest years in the 1980s) is of the same magnitude
as natural climate variability.  The warming could be due to this; or
possibly, the variability and other human factors contributing to cooling
could have offset an even greater warming.

4) It is misleading to say that the warming isn't happening.  We know
that *theoretically* the increase in certain gases in the atmosphere
will result in a warmer climate.  This theoretical smooth curve will
be broken to bits by things such as natural variability, biological
effects (such as the coral alluded to in the original thread), and
other gases with cooling effects (sulfur compounds from volcanos and
industrial emissions, for example).

Screaming that catastrophic global warming is inevitable is a misleading
mistake, but dismissing it out of hand is another mistake. 

				Ilana

[Numbers and facts in this posting are from the WMO IPCC summary,
_Scientific Assessment of Climate Change_.  I may post excerpts from it
in sci.environment if I have time, and if I can get permission from the
IPCC chairman.  Opinions are not the official opinions of NCAR.  The
DoD# in my signature has nothing to do with the Department of Defense.]

--
	     Ilana Stern / ilana@ncar.ucar.edu / DoD #00009
	The throttle acts primarily as an occasional form of 
		    humor and social commentary.


Brought to you by Super Global Mega Corp .com