NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/sci/environm/14334

Internet Message Format | 1993-01-06 | 2.8 KB

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From: [e-mail] (Bryan Joseph Hannegan)
Subject: Re: What is Climate?
Nntp-Posting-Host: orion.oac.uci.edu
Message-ID: <[e-mail]>
Newsgroups: sci.environment
Organization: University of California, Irvine
Lines: 40
Date: 7 Jan 93 03:59:23 GMT
References: <[e-mail]> <[e-mail]>

In article <[e-mail]> [e-mail] (David Halliwell) writes:
>
>(...) figure out how long a period is required to observe all possible
>variability for a given set of boundary conditions. A "climate change"
>would be a shift in climate which is attributable to some change in
>controlling conditions (e.g. solar output, or some aspect of internal
>conditions which is independent of the climatic variabilty). Thus,
>variability is the time-dependent behaviour which cannot be attributed
>to time-dependent controlling factors. If we have incorrectly seperated
>"variability" and "change", then we may spend a lot of time looking for
>the cause of "changes" which were in fact "variation" and therefore
>are "unexplainable".
>

     Paleoclimatology seems like a candidate field for these kinds of things.
Can we really be sure that all the variability can be observed? Must the full
range of variability be observed before we can surely attribute climate change
to its rightful forcing mechanism? I'm pessimistic concerning ideas like these,
since I am not sure that the wide range of variability will ever be experienced
for a single set of static boundary conditions, much less the continually
changing and dynamic boundary conditions that exist today.

     The definition I received in my undergrad years lead me to believe that
climate is simply "average weather", including all the extremes and midpoints.
A little narrow, I agree, but for me this suffices, since it leaves vague
the more specific points of "over how long of a time, and how big of an area?".
Climate change studies, like those we do at UC Irvine, revolve around the
shifts that can be attributed to something outside of the system (like Dave
mentioned above), and as such, for the purposes of our inquiry, the definition
of climate we use can be safely redefined to best express the changes we find,
for the definition can vary without disturbing the study. A lot of the work
on climate change I have come into contact with has a similar feature.

     I'll definitely chew on this some more.

--
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Bryan Hannegan                              [e-mail]
Dept of Geosciences, UC-Irvine              [e-mail]
If you fall on your face, at least take heart in making forward progress.